{"id":15314668,"url":"https://github.com/unframework/u-boot","last_synced_at":"2025-10-09T00:32:38.369Z","repository":{"id":48805674,"uuid":"345245012","full_name":"unframework/u-boot","owner":"unframework","description":"\"Das U-Boot\" Source Tree  (cherry-picked Icenowy/u-boot f1c100s-spiflash branch et al as of 2021-03)","archived":false,"fork":true,"pushed_at":"2023-02-12T16:31:15.000Z","size":214636,"stargazers_count":2,"open_issues_count":0,"forks_count":2,"subscribers_count":1,"default_branch":"2021.01-f1c100s","last_synced_at":"2024-10-02T08:46:26.042Z","etag":null,"topics":[],"latest_commit_sha":null,"homepage":"","language":"C","has_issues":false,"has_wiki":null,"has_pages":null,"mirror_url":null,"source_name":"u-boot/u-boot","license":null,"status":null,"scm":"git","pull_requests_enabled":true,"icon_url":"https://github.com/unframework.png","metadata":{"files":{"readme":"README","changelog":null,"contributing":null,"funding":null,"license":"Licenses/Exceptions","code_of_conduct":null,"threat_model":null,"audit":null,"citation":null,"codeowners":null,"security":null,"support":null}},"created_at":"2021-03-07T02:56:28.000Z","updated_at":"2023-02-12T04:50:20.000Z","dependencies_parsed_at":null,"dependency_job_id":null,"html_url":"https://github.com/unframework/u-boot","commit_stats":null,"previous_names":[],"tags_count":0,"template":false,"template_full_name":null,"repository_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/repositories/unframework%2Fu-boot","tags_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/repositories/unframework%2Fu-boot/tags","releases_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/repositories/unframework%2Fu-boot/releases","manifests_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/repositories/unframework%2Fu-boot/manifests","owner_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/owners/unframework","download_url":"https://codeload.github.com/unframework/u-boot/tar.gz/refs/heads/2021.01-f1c100s","host":{"name":"GitHub","url":"https://github.com","kind":"github","repositories_count":235781122,"owners_count":19043929,"icon_url":"https://github.com/github.png","version":null,"created_at":"2022-05-30T11:31:42.601Z","updated_at":"2022-07-04T15:15:14.044Z","host_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub","repositories_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/repositories","repository_names_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/repository_names","owners_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/owners"}},"keywords":[],"created_at":"2024-10-01T08:46:37.167Z","updated_at":"2025-10-09T00:32:28.973Z","avatar_url":"https://github.com/unframework.png","language":"C","readme":"# SPDX-License-Identifier: GPL-2.0+\n#\n# (C) Copyright 2000 - 2013\n# Wolfgang Denk, DENX Software Engineering, wd@denx.de.\n\nSummary:\n========\n\nThis directory contains the source code for U-Boot, a boot loader for\nEmbedded boards based on PowerPC, ARM, MIPS and several other\nprocessors, which can be installed in a boot ROM and used to\ninitialize and test the hardware or to download and run application\ncode.\n\nThe development of U-Boot is closely related to Linux: some parts of\nthe source code originate in the Linux source tree, we have some\nheader files in common, and special provision has been made to\nsupport booting of Linux images.\n\nSome attention has been paid to make this software easily\nconfigurable and extendable. For instance, all monitor commands are\nimplemented with the same call interface, so that it's very easy to\nadd new commands. Also, instead of permanently adding rarely used\ncode (for instance hardware test utilities) to the monitor, you can\nload and run it dynamically.\n\n\nStatus:\n=======\n\nIn general, all boards for which a configuration option exists in the\nMakefile have been tested to some extent and can be considered\n\"working\". In fact, many of them are used in production systems.\n\nIn case of problems see the CHANGELOG file to find out who contributed\nthe specific port. In addition, there are various MAINTAINERS files\nscattered throughout the U-Boot source identifying the people or\ncompanies responsible for various boards and subsystems.\n\nNote: As of August, 2010, there is no longer a CHANGELOG file in the\nactual U-Boot source tree; however, it can be created dynamically\nfrom the Git log using:\n\n\tmake CHANGELOG\n\n\nWhere to get help:\n==================\n\nIn case you have questions about, problems with or contributions for\nU-Boot, you should send a message to the U-Boot mailing list at\n\u003cu-boot@lists.denx.de\u003e. There is also an archive of previous traffic\non the mailing list - please search the archive before asking FAQ's.\nPlease see https://lists.denx.de/pipermail/u-boot and\nhttps://marc.info/?l=u-boot\n\nWhere to get source code:\n=========================\n\nThe U-Boot source code is maintained in the Git repository at\nhttps://gitlab.denx.de/u-boot/u-boot.git ; you can browse it online at\nhttps://gitlab.denx.de/u-boot/u-boot\n\nThe \"Tags\" links on this page allow you to download tarballs of\nany version you might be interested in. Official releases are also\navailable from the DENX file server through HTTPS or FTP.\nhttps://ftp.denx.de/pub/u-boot/\nftp://ftp.denx.de/pub/u-boot/\n\n\nWhere we come from:\n===================\n\n- start from 8xxrom sources\n- create PPCBoot project (https://sourceforge.net/projects/ppcboot)\n- clean up code\n- make it easier to add custom boards\n- make it possible to add other [PowerPC] CPUs\n- extend functions, especially:\n  * Provide extended interface to Linux boot loader\n  * S-Record download\n  * network boot\n  * ATA disk / SCSI ... boot\n- create ARMBoot project (https://sourceforge.net/projects/armboot)\n- add other CPU families (starting with ARM)\n- create U-Boot project (https://sourceforge.net/projects/u-boot)\n- current project page: see https://www.denx.de/wiki/U-Boot\n\n\nNames and Spelling:\n===================\n\nThe \"official\" name of this project is \"Das U-Boot\". The spelling\n\"U-Boot\" shall be used in all written text (documentation, comments\nin source files etc.). Example:\n\n\tThis is the README file for the U-Boot project.\n\nFile names etc. shall be based on the string \"u-boot\". Examples:\n\n\tinclude/asm-ppc/u-boot.h\n\n\t#include \u003casm/u-boot.h\u003e\n\nVariable names, preprocessor constants etc. shall be either based on\nthe string \"u_boot\" or on \"U_BOOT\". Example:\n\n\tU_BOOT_VERSION\t\tu_boot_logo\n\tIH_OS_U_BOOT\t\tu_boot_hush_start\n\n\nVersioning:\n===========\n\nStarting with the release in October 2008, the names of the releases\nwere changed from numerical release numbers without deeper meaning\ninto a time stamp based numbering. Regular releases are identified by\nnames consisting of the calendar year and month of the release date.\nAdditional fields (if present) indicate release candidates or bug fix\nreleases in \"stable\" maintenance trees.\n\nExamples:\n\tU-Boot v2009.11\t    - Release November 2009\n\tU-Boot v2009.11.1   - Release 1 in version November 2009 stable tree\n\tU-Boot v2010.09-rc1 - Release candidate 1 for September 2010 release\n\n\nDirectory Hierarchy:\n====================\n\n/arch\t\t\tArchitecture specific files\n  /arc\t\t\tFiles generic to ARC architecture\n  /arm\t\t\tFiles generic to ARM architecture\n  /m68k\t\t\tFiles generic to m68k architecture\n  /microblaze\t\tFiles generic to microblaze architecture\n  /mips\t\t\tFiles generic to MIPS architecture\n  /nds32\t\tFiles generic to NDS32 architecture\n  /nios2\t\tFiles generic to Altera NIOS2 architecture\n  /powerpc\t\tFiles generic to PowerPC architecture\n  /riscv\t\tFiles generic to RISC-V architecture\n  /sandbox\t\tFiles generic to HW-independent \"sandbox\"\n  /sh\t\t\tFiles generic to SH architecture\n  /x86\t\t\tFiles generic to x86 architecture\n  /xtensa\t\tFiles generic to Xtensa architecture\n/api\t\t\tMachine/arch independent API for external apps\n/board\t\t\tBoard dependent files\n/cmd\t\t\tU-Boot commands functions\n/common\t\t\tMisc architecture independent functions\n/configs\t\tBoard default configuration files\n/disk\t\t\tCode for disk drive partition handling\n/doc\t\t\tDocumentation (don't expect too much)\n/drivers\t\tCommonly used device drivers\n/dts\t\t\tContains Makefile for building internal U-Boot fdt.\n/env\t\t\tEnvironment files\n/examples\t\tExample code for standalone applications, etc.\n/fs\t\t\tFilesystem code (cramfs, ext2, jffs2, etc.)\n/include\t\tHeader Files\n/lib\t\t\tLibrary routines generic to all architectures\n/Licenses\t\tVarious license files\n/net\t\t\tNetworking code\n/post\t\t\tPower On Self Test\n/scripts\t\tVarious build scripts and Makefiles\n/test\t\t\tVarious unit test files\n/tools\t\t\tTools to build S-Record or U-Boot images, etc.\n\nSoftware Configuration:\n=======================\n\nConfiguration is usually done using C preprocessor defines; the\nrationale behind that is to avoid dead code whenever possible.\n\nThere are two classes of configuration variables:\n\n* Configuration _OPTIONS_:\n  These are selectable by the user and have names beginning with\n  \"CONFIG_\".\n\n* Configuration _SETTINGS_:\n  These depend on the hardware etc. and should not be meddled with if\n  you don't know what you're doing; they have names beginning with\n  \"CONFIG_SYS_\".\n\nPreviously, all configuration was done by hand, which involved creating\nsymbolic links and editing configuration files manually. More recently,\nU-Boot has added the Kbuild infrastructure used by the Linux kernel,\nallowing you to use the \"make menuconfig\" command to configure your\nbuild.\n\n\nSelection of Processor Architecture and Board Type:\n---------------------------------------------------\n\nFor all supported boards there are ready-to-use default\nconfigurations available; just type \"make \u003cboard_name\u003e_defconfig\".\n\nExample: For a TQM823L module type:\n\n\tcd u-boot\n\tmake TQM823L_defconfig\n\nNote: If you're looking for the default configuration file for a board\nyou're sure used to be there but is now missing, check the file\ndoc/README.scrapyard for a list of no longer supported boards.\n\nSandbox Environment:\n--------------------\n\nU-Boot can be built natively to run on a Linux host using the 'sandbox'\nboard. This allows feature development which is not board- or architecture-\nspecific to be undertaken on a native platform. The sandbox is also used to\nrun some of U-Boot's tests.\n\nSee doc/arch/sandbox.rst for more details.\n\n\nBoard Initialisation Flow:\n--------------------------\n\nThis is the intended start-up flow for boards. This should apply for both\nSPL and U-Boot proper (i.e. they both follow the same rules).\n\nNote: \"SPL\" stands for \"Secondary Program Loader,\" which is explained in\nmore detail later in this file.\n\nAt present, SPL mostly uses a separate code path, but the function names\nand roles of each function are the same. Some boards or architectures\nmay not conform to this.  At least most ARM boards which use\nCONFIG_SPL_FRAMEWORK conform to this.\n\nExecution typically starts with an architecture-specific (and possibly\nCPU-specific) start.S file, such as:\n\n\t- arch/arm/cpu/armv7/start.S\n\t- arch/powerpc/cpu/mpc83xx/start.S\n\t- arch/mips/cpu/start.S\n\nand so on. From there, three functions are called; the purpose and\nlimitations of each of these functions are described below.\n\nlowlevel_init():\n\t- purpose: essential init to permit execution to reach board_init_f()\n\t- no global_data or BSS\n\t- there is no stack (ARMv7 may have one but it will soon be removed)\n\t- must not set up SDRAM or use console\n\t- must only do the bare minimum to allow execution to continue to\n\t\tboard_init_f()\n\t- this is almost never needed\n\t- return normally from this function\n\nboard_init_f():\n\t- purpose: set up the machine ready for running board_init_r():\n\t\ti.e. SDRAM and serial UART\n\t- global_data is available\n\t- stack is in SRAM\n\t- BSS is not available, so you cannot use global/static variables,\n\t\tonly stack variables and global_data\n\n\tNon-SPL-specific notes:\n\t- dram_init() is called to set up DRAM. If already done in SPL this\n\t\tcan do nothing\n\n\tSPL-specific notes:\n\t- you can override the entire board_init_f() function with your own\n\t\tversion as needed.\n\t- preloader_console_init() can be called here in extremis\n\t- should set up SDRAM, and anything needed to make the UART work\n\t- there is no need to clear BSS, it will be done by crt0.S\n\t- for specific scenarios on certain architectures an early BSS *can*\n\t  be made available (via CONFIG_SPL_EARLY_BSS by moving the clearing\n\t  of BSS prior to entering board_init_f()) but doing so is discouraged.\n\t  Instead it is strongly recommended to architect any code changes\n\t  or additions such to not depend on the availability of BSS during\n\t  board_init_f() as indicated in other sections of this README to\n\t  maintain compatibility and consistency across the entire code base.\n\t- must return normally from this function (don't call board_init_r()\n\t\tdirectly)\n\nHere the BSS is cleared. For SPL, if CONFIG_SPL_STACK_R is defined, then at\nthis point the stack and global_data are relocated to below\nCONFIG_SPL_STACK_R_ADDR. For non-SPL, U-Boot is relocated to run at the top of\nmemory.\n\nboard_init_r():\n\t- purpose: main execution, common code\n\t- global_data is available\n\t- SDRAM is available\n\t- BSS is available, all static/global variables can be used\n\t- execution eventually continues to main_loop()\n\n\tNon-SPL-specific notes:\n\t- U-Boot is relocated to the top of memory and is now running from\n\t\tthere.\n\n\tSPL-specific notes:\n\t- stack is optionally in SDRAM, if CONFIG_SPL_STACK_R is defined and\n\t\tCONFIG_SPL_STACK_R_ADDR points into SDRAM\n\t- preloader_console_init() can be called here - typically this is\n\t\tdone by selecting CONFIG_SPL_BOARD_INIT and then supplying a\n\t\tspl_board_init() function containing this call\n\t- loads U-Boot or (in falcon mode) Linux\n\n\n\nConfiguration Options:\n----------------------\n\nConfiguration depends on the combination of board and CPU type; all\nsuch information is kept in a configuration file\n\"include/configs/\u003cboard_name\u003e.h\".\n\nExample: For a TQM823L module, all configuration settings are in\n\"include/configs/TQM823L.h\".\n\n\nMany of the options are named exactly as the corresponding Linux\nkernel configuration options. The intention is to make it easier to\nbuild a config tool - later.\n\n- ARM Platform Bus Type(CCI):\n\t\tCoreLink Cache Coherent Interconnect (CCI) is ARM BUS which\n\t\tprovides full cache coherency between two clusters of multi-core\n\t\tCPUs and I/O coherency for devices and I/O masters\n\n\t\tCONFIG_SYS_FSL_HAS_CCI400\n\n\t\tDefined For SoC that has cache coherent interconnect\n\t\tCCN-400\n\n\t\tCONFIG_SYS_FSL_HAS_CCN504\n\n\t\tDefined for SoC that has cache coherent interconnect CCN-504\n\nThe following options need to be configured:\n\n- CPU Type:\tDefine exactly one, e.g. CONFIG_MPC85XX.\n\n- Board Type:\tDefine exactly one, e.g. CONFIG_MPC8540ADS.\n\n- 85xx CPU Options:\n\t\tCONFIG_SYS_PPC64\n\n\t\tSpecifies that the core is a 64-bit PowerPC implementation (implements\n\t\tthe \"64\" category of the Power ISA). This is necessary for ePAPR\n\t\tcompliance, among other possible reasons.\n\n\t\tCONFIG_SYS_FSL_TBCLK_DIV\n\n\t\tDefines the core time base clock divider ratio compared to the\n\t\tsystem clock.  On most PQ3 devices this is 8, on newer QorIQ\n\t\tdevices it can be 16 or 32.  The ratio varies from SoC to Soc.\n\n\t\tCONFIG_SYS_FSL_PCIE_COMPAT\n\n\t\tDefines the string to utilize when trying to match PCIe device\n\t\ttree nodes for the given platform.\n\n\t\tCONFIG_SYS_FSL_ERRATUM_A004510\n\n\t\tEnables a workaround for erratum A004510.  If set,\n\t\tthen CONFIG_SYS_FSL_ERRATUM_A004510_SVR_REV and\n\t\tCONFIG_SYS_FSL_CORENET_SNOOPVEC_COREONLY must be set.\n\n\t\tCONFIG_SYS_FSL_ERRATUM_A004510_SVR_REV\n\t\tCONFIG_SYS_FSL_ERRATUM_A004510_SVR_REV2 (optional)\n\n\t\tDefines one or two SoC revisions (low 8 bits of SVR)\n\t\tfor which the A004510 workaround should be applied.\n\n\t\tThe rest of SVR is either not relevant to the decision\n\t\tof whether the erratum is present (e.g. p2040 versus\n\t\tp2041) or is implied by the build target, which controls\n\t\twhether CONFIG_SYS_FSL_ERRATUM_A004510 is set.\n\n\t\tSee Freescale App Note 4493 for more information about\n\t\tthis erratum.\n\n\t\tCONFIG_A003399_NOR_WORKAROUND\n\t\tEnables a workaround for IFC erratum A003399. It is only\n\t\trequired during NOR boot.\n\n\t\tCONFIG_A008044_WORKAROUND\n\t\tEnables a workaround for T1040/T1042 erratum A008044. It is only\n\t\trequired during NAND boot and valid for Rev 1.0 SoC revision\n\n\t\tCONFIG_SYS_FSL_CORENET_SNOOPVEC_COREONLY\n\n\t\tThis is the value to write into CCSR offset 0x18600\n\t\taccording to the A004510 workaround.\n\n\t\tCONFIG_SYS_FSL_DSP_DDR_ADDR\n\t\tThis value denotes start offset of DDR memory which is\n\t\tconnected exclusively to the DSP cores.\n\n\t\tCONFIG_SYS_FSL_DSP_M2_RAM_ADDR\n\t\tThis value denotes start offset of M2 memory\n\t\twhich is directly connected to the DSP core.\n\n\t\tCONFIG_SYS_FSL_DSP_M3_RAM_ADDR\n\t\tThis value denotes start offset of M3 memory which is directly\n\t\tconnected to the DSP core.\n\n\t\tCONFIG_SYS_FSL_DSP_CCSRBAR_DEFAULT\n\t\tThis value denotes start offset of DSP CCSR space.\n\n\t\tCONFIG_SYS_FSL_SINGLE_SOURCE_CLK\n\t\tSingle Source Clock is clocking mode present in some of FSL SoC's.\n\t\tIn this mode, a single differential clock is used to supply\n\t\tclocks to the sysclock, ddrclock and usbclock.\n\n\t\tCONFIG_SYS_CPC_REINIT_F\n\t\tThis CONFIG is defined when the CPC is configured as SRAM at the\n\t\ttime of U-Boot entry and is required to be re-initialized.\n\n\t\tCONFIG_DEEP_SLEEP\n\t\tIndicates this SoC supports deep sleep feature. If deep sleep is\n\t\tsupported, core will start to execute uboot when wakes up.\n\n- Generic CPU options:\n\t\tCONFIG_SYS_BIG_ENDIAN, CONFIG_SYS_LITTLE_ENDIAN\n\n\t\tDefines the endianess of the CPU. Implementation of those\n\t\tvalues is arch specific.\n\n\t\tCONFIG_SYS_FSL_DDR\n\t\tFreescale DDR driver in use. This type of DDR controller is\n\t\tfound in mpc83xx, mpc85xx, mpc86xx as well as some ARM core\n\t\tSoCs.\n\n\t\tCONFIG_SYS_FSL_DDR_ADDR\n\t\tFreescale DDR memory-mapped register base.\n\n\t\tCONFIG_SYS_FSL_DDR_EMU\n\t\tSpecify emulator support for DDR. Some DDR features such as\n\t\tdeskew training are not available.\n\n\t\tCONFIG_SYS_FSL_DDRC_GEN1\n\t\tFreescale DDR1 controller.\n\n\t\tCONFIG_SYS_FSL_DDRC_GEN2\n\t\tFreescale DDR2 controller.\n\n\t\tCONFIG_SYS_FSL_DDRC_GEN3\n\t\tFreescale DDR3 controller.\n\n\t\tCONFIG_SYS_FSL_DDRC_GEN4\n\t\tFreescale DDR4 controller.\n\n\t\tCONFIG_SYS_FSL_DDRC_ARM_GEN3\n\t\tFreescale DDR3 controller for ARM-based SoCs.\n\n\t\tCONFIG_SYS_FSL_DDR1\n\t\tBoard config to use DDR1. It can be enabled for SoCs with\n\t\tFreescale DDR1 or DDR2 controllers, depending on the board\n\t\timplemetation.\n\n\t\tCONFIG_SYS_FSL_DDR2\n\t\tBoard config to use DDR2. It can be enabled for SoCs with\n\t\tFreescale DDR2 or DDR3 controllers, depending on the board\n\t\timplementation.\n\n\t\tCONFIG_SYS_FSL_DDR3\n\t\tBoard config to use DDR3. It can be enabled for SoCs with\n\t\tFreescale DDR3 or DDR3L controllers.\n\n\t\tCONFIG_SYS_FSL_DDR3L\n\t\tBoard config to use DDR3L. It can be enabled for SoCs with\n\t\tDDR3L controllers.\n\n\t\tCONFIG_SYS_FSL_DDR4\n\t\tBoard config to use DDR4. It can be enabled for SoCs with\n\t\tDDR4 controllers.\n\n\t\tCONFIG_SYS_FSL_IFC_BE\n\t\tDefines the IFC controller register space as Big Endian\n\n\t\tCONFIG_SYS_FSL_IFC_LE\n\t\tDefines the IFC controller register space as Little Endian\n\n\t\tCONFIG_SYS_FSL_IFC_CLK_DIV\n\t\tDefines divider of platform clock(clock input to IFC controller).\n\n\t\tCONFIG_SYS_FSL_LBC_CLK_DIV\n\t\tDefines divider of platform clock(clock input to eLBC controller).\n\n\t\tCONFIG_SYS_FSL_PBL_PBI\n\t\tIt enables addition of RCW (Power on reset configuration) in built image.\n\t\tPlease refer doc/README.pblimage for more details\n\n\t\tCONFIG_SYS_FSL_PBL_RCW\n\t\tIt adds PBI(pre-boot instructions) commands in u-boot build image.\n\t\tPBI commands can be used to configure SoC before it starts the execution.\n\t\tPlease refer doc/README.pblimage for more details\n\n\t\tCONFIG_SYS_FSL_DDR_BE\n\t\tDefines the DDR controller register space as Big Endian\n\n\t\tCONFIG_SYS_FSL_DDR_LE\n\t\tDefines the DDR controller register space as Little Endian\n\n\t\tCONFIG_SYS_FSL_DDR_SDRAM_BASE_PHY\n\t\tPhysical address from the view of DDR controllers. It is the\n\t\tsame as CONFIG_SYS_DDR_SDRAM_BASE for  all Power SoCs. But\n\t\tit could be different for ARM SoCs.\n\n\t\tCONFIG_SYS_FSL_DDR_INTLV_256B\n\t\tDDR controller interleaving on 256-byte. This is a special\n\t\tinterleaving mode, handled by Dickens for Freescale layerscape\n\t\tSoCs with ARM core.\n\n\t\tCONFIG_SYS_FSL_DDR_MAIN_NUM_CTRLS\n\t\tNumber of controllers used as main memory.\n\n\t\tCONFIG_SYS_FSL_OTHER_DDR_NUM_CTRLS\n\t\tNumber of controllers used for other than main memory.\n\n\t\tCONFIG_SYS_FSL_HAS_DP_DDR\n\t\tDefines the SoC has DP-DDR used for DPAA.\n\n\t\tCONFIG_SYS_FSL_SEC_BE\n\t\tDefines the SEC controller register space as Big Endian\n\n\t\tCONFIG_SYS_FSL_SEC_LE\n\t\tDefines the SEC controller register space as Little Endian\n\n- MIPS CPU options:\n\t\tCONFIG_SYS_INIT_SP_OFFSET\n\n\t\tOffset relative to CONFIG_SYS_SDRAM_BASE for initial stack\n\t\tpointer. This is needed for the temporary stack before\n\t\trelocation.\n\n\t\tCONFIG_XWAY_SWAP_BYTES\n\n\t\tEnable compilation of tools/xway-swap-bytes needed for Lantiq\n\t\tXWAY SoCs for booting from NOR flash. The U-Boot image needs to\n\t\tbe swapped if a flash programmer is used.\n\n- ARM options:\n\t\tCONFIG_SYS_EXCEPTION_VECTORS_HIGH\n\n\t\tSelect high exception vectors of the ARM core, e.g., do not\n\t\tclear the V bit of the c1 register of CP15.\n\n\t\tCOUNTER_FREQUENCY\n\t\tGeneric timer clock source frequency.\n\n\t\tCOUNTER_FREQUENCY_REAL\n\t\tGeneric timer clock source frequency if the real clock is\n\t\tdifferent from COUNTER_FREQUENCY, and can only be determined\n\t\tat run time.\n\n- Tegra SoC options:\n\t\tCONFIG_TEGRA_SUPPORT_NON_SECURE\n\n\t\tSupport executing U-Boot in non-secure (NS) mode. Certain\n\t\timpossible actions will be skipped if the CPU is in NS mode,\n\t\tsuch as ARM architectural timer initialization.\n\n- Linux Kernel Interface:\n\t\tCONFIG_MEMSIZE_IN_BYTES\t\t[relevant for MIPS only]\n\n\t\tWhen transferring memsize parameter to Linux, some versions\n\t\texpect it to be in bytes, others in MB.\n\t\tDefine CONFIG_MEMSIZE_IN_BYTES to make it in bytes.\n\n\t\tCONFIG_OF_LIBFDT\n\n\t\tNew kernel versions are expecting firmware settings to be\n\t\tpassed using flattened device trees (based on open firmware\n\t\tconcepts).\n\n\t\tCONFIG_OF_LIBFDT\n\t\t * New libfdt-based support\n\t\t * Adds the \"fdt\" command\n\t\t * The bootm command automatically updates the fdt\n\n\t\tOF_TBCLK - The timebase frequency.\n\t\tOF_STDOUT_PATH - The path to the console device\n\n\t\tboards with QUICC Engines require OF_QE to set UCC MAC\n\t\taddresses\n\n\t\tCONFIG_OF_BOARD_SETUP\n\n\t\tBoard code has addition modification that it wants to make\n\t\tto the flat device tree before handing it off to the kernel\n\n\t\tCONFIG_OF_SYSTEM_SETUP\n\n\t\tOther code has addition modification that it wants to make\n\t\tto the flat device tree before handing it off to the kernel.\n\t\tThis causes ft_system_setup() to be called before booting\n\t\tthe kernel.\n\n\t\tCONFIG_OF_IDE_FIXUP\n\n\t\tU-Boot can detect if an IDE device is present or not.\n\t\tIf not, and this new config option is activated, U-Boot\n\t\tremoves the ATA node from the DTS before booting Linux,\n\t\tso the Linux IDE driver does not probe the device and\n\t\tcrash. This is needed for buggy hardware (uc101) where\n\t\tno pull down resistor is connected to the signal IDE5V_DD7.\n\n\t\tCONFIG_MACH_TYPE\t[relevant for ARM only][mandatory]\n\n\t\tThis setting is mandatory for all boards that have only one\n\t\tmachine type and must be used to specify the machine type\n\t\tnumber as it appears in the ARM machine registry\n\t\t(see https://www.arm.linux.org.uk/developer/machines/).\n\t\tOnly boards that have multiple machine types supported\n\t\tin a single configuration file and the machine type is\n\t\truntime discoverable, do not have to use this setting.\n\n- vxWorks boot parameters:\n\n\t\tbootvx constructs a valid bootline using the following\n\t\tenvironments variables: bootdev, bootfile, ipaddr, netmask,\n\t\tserverip, gatewayip, hostname, othbootargs.\n\t\tIt loads the vxWorks image pointed bootfile.\n\n\t\tNote: If a \"bootargs\" environment is defined, it will override\n\t\tthe defaults discussed just above.\n\n- Cache Configuration:\n\t\tCONFIG_SYS_L2CACHE_OFF- Do not enable L2 cache in U-Boot\n\n- Cache Configuration for ARM:\n\t\tCONFIG_SYS_L2_PL310 - Enable support for ARM PL310 L2 cache\n\t\t\t\t      controller\n\t\tCONFIG_SYS_PL310_BASE - Physical base address of PL310\n\t\t\t\t\tcontroller register space\n\n- Serial Ports:\n\t\tCONFIG_PL010_SERIAL\n\n\t\tDefine this if you want support for Amba PrimeCell PL010 UARTs.\n\n\t\tCONFIG_PL011_SERIAL\n\n\t\tDefine this if you want support for Amba PrimeCell PL011 UARTs.\n\n\t\tCONFIG_PL011_CLOCK\n\n\t\tIf you have Amba PrimeCell PL011 UARTs, set this variable to\n\t\tthe clock speed of the UARTs.\n\n\t\tCONFIG_PL01x_PORTS\n\n\t\tIf you have Amba PrimeCell PL010 or PL011 UARTs on your board,\n\t\tdefine this to a list of base addresses for each (supported)\n\t\tport. See e.g. include/configs/versatile.h\n\n\t\tCONFIG_SERIAL_HW_FLOW_CONTROL\n\n\t\tDefine this variable to enable hw flow control in serial driver.\n\t\tCurrent user of this option is drivers/serial/nsl16550.c driver\n\n- Autoboot Command:\n\t\tCONFIG_BOOTCOMMAND\n\t\tOnly needed when CONFIG_BOOTDELAY is enabled;\n\t\tdefine a command string that is automatically executed\n\t\twhen no character is read on the console interface\n\t\twithin \"Boot Delay\" after reset.\n\n\t\tCONFIG_RAMBOOT and CONFIG_NFSBOOT\n\t\tThe value of these goes into the environment as\n\t\t\"ramboot\" and \"nfsboot\" respectively, and can be used\n\t\tas a convenience, when switching between booting from\n\t\tRAM and NFS.\n\n- Serial Download Echo Mode:\n\t\tCONFIG_LOADS_ECHO\n\t\tIf defined to 1, all characters received during a\n\t\tserial download (using the \"loads\" command) are\n\t\techoed back. This might be needed by some terminal\n\t\temulations (like \"cu\"), but may as well just take\n\t\ttime on others. This setting #define's the initial\n\t\tvalue of the \"loads_echo\" environment variable.\n\n- Kgdb Serial Baudrate: (if CONFIG_CMD_KGDB is defined)\n\t\tCONFIG_KGDB_BAUDRATE\n\t\tSelect one of the baudrates listed in\n\t\tCONFIG_SYS_BAUDRATE_TABLE, see below.\n\n- Removal of commands\n\t\tIf no commands are needed to boot, you can disable\n\t\tCONFIG_CMDLINE to remove them. In this case, the command line\n\t\twill not be available, and when U-Boot wants to execute the\n\t\tboot command (on start-up) it will call board_run_command()\n\t\tinstead. This can reduce image size significantly for very\n\t\tsimple boot procedures.\n\n- Regular expression support:\n\t\tCONFIG_REGEX\n\t\tIf this variable is defined, U-Boot is linked against\n\t\tthe SLRE (Super Light Regular Expression) library,\n\t\twhich adds regex support to some commands, as for\n\t\texample \"env grep\" and \"setexpr\".\n\n- Device tree:\n\t\tCONFIG_OF_CONTROL\n\t\tIf this variable is defined, U-Boot will use a device tree\n\t\tto configure its devices, instead of relying on statically\n\t\tcompiled #defines in the board file. This option is\n\t\texperimental and only available on a few boards. The device\n\t\ttree is available in the global data as gd-\u003efdt_blob.\n\n\t\tU-Boot needs to get its device tree from somewhere. This can\n\t\tbe done using one of the three options below:\n\n\t\tCONFIG_OF_EMBED\n\t\tIf this variable is defined, U-Boot will embed a device tree\n\t\tbinary in its image. This device tree file should be in the\n\t\tboard directory and called \u003csoc\u003e-\u003cboard\u003e.dts. The binary file\n\t\tis then picked up in board_init_f() and made available through\n\t\tthe global data structure as gd-\u003efdt_blob.\n\n\t\tCONFIG_OF_SEPARATE\n\t\tIf this variable is defined, U-Boot will build a device tree\n\t\tbinary. It will be called u-boot.dtb. Architecture-specific\n\t\tcode will locate it at run-time. Generally this works by:\n\n\t\t\tcat u-boot.bin u-boot.dtb \u003eimage.bin\n\n\t\tand in fact, U-Boot does this for you, creating a file called\n\t\tu-boot-dtb.bin which is useful in the common case. You can\n\t\tstill use the individual files if you need something more\n\t\texotic.\n\n\t\tCONFIG_OF_BOARD\n\t\tIf this variable is defined, U-Boot will use the device tree\n\t\tprovided by the board at runtime instead of embedding one with\n\t\tthe image. Only boards defining board_fdt_blob_setup() support\n\t\tthis option (see include/fdtdec.h file).\n\n- Watchdog:\n\t\tCONFIG_WATCHDOG\n\t\tIf this variable is defined, it enables watchdog\n\t\tsupport for the SoC. There must be support in the SoC\n\t\tspecific code for a watchdog. For the 8xx\n\t\tCPUs, the SIU Watchdog feature is enabled in the SYPCR\n\t\tregister.  When supported for a specific SoC is\n\t\tavailable, then no further board specific code should\n\t\tbe needed to use it.\n\n\t\tCONFIG_HW_WATCHDOG\n\t\tWhen using a watchdog circuitry external to the used\n\t\tSoC, then define this variable and provide board\n\t\tspecific code for the \"hw_watchdog_reset\" function.\n\n- Real-Time Clock:\n\n\t\tWhen CONFIG_CMD_DATE is selected, the type of the RTC\n\t\thas to be selected, too. Define exactly one of the\n\t\tfollowing options:\n\n\t\tCONFIG_RTC_PCF8563\t- use Philips PCF8563 RTC\n\t\tCONFIG_RTC_MC13XXX\t- use MC13783 or MC13892 RTC\n\t\tCONFIG_RTC_MC146818\t- use MC146818 RTC\n\t\tCONFIG_RTC_DS1307\t- use Maxim, Inc. DS1307 RTC\n\t\tCONFIG_RTC_DS1337\t- use Maxim, Inc. DS1337 RTC\n\t\tCONFIG_RTC_DS1338\t- use Maxim, Inc. DS1338 RTC\n\t\tCONFIG_RTC_DS1339\t- use Maxim, Inc. DS1339 RTC\n\t\tCONFIG_RTC_DS164x\t- use Dallas DS164x RTC\n\t\tCONFIG_RTC_ISL1208\t- use Intersil ISL1208 RTC\n\t\tCONFIG_RTC_MAX6900\t- use Maxim, Inc. MAX6900 RTC\n\t\tCONFIG_RTC_DS1337_NOOSC\t- Turn off the OSC output for DS1337\n\t\tCONFIG_SYS_RV3029_TCR\t- enable trickle charger on\n\t\t\t\t\t  RV3029 RTC.\n\n\t\tNote that if the RTC uses I2C, then the I2C interface\n\t\tmust also be configured. See I2C Support, below.\n\n- GPIO Support:\n\t\tCONFIG_PCA953X\t\t- use NXP's PCA953X series I2C GPIO\n\n\t\tThe CONFIG_SYS_I2C_PCA953X_WIDTH option specifies a list of\n\t\tchip-ngpio pairs that tell the PCA953X driver the number of\n\t\tpins supported by a particular chip.\n\n\t\tNote that if the GPIO device uses I2C, then the I2C interface\n\t\tmust also be configured. See I2C Support, below.\n\n- I/O tracing:\n\t\tWhen CONFIG_IO_TRACE is selected, U-Boot intercepts all I/O\n\t\taccesses and can checksum them or write a list of them out\n\t\tto memory. See the 'iotrace' command for details. This is\n\t\tuseful for testing device drivers since it can confirm that\n\t\tthe driver behaves the same way before and after a code\n\t\tchange. Currently this is supported on sandbox and arm. To\n\t\tadd support for your architecture, add '#include \u003ciotrace.h\u003e'\n\t\tto the bottom of arch/\u003carch\u003e/include/asm/io.h and test.\n\n\t\tExample output from the 'iotrace stats' command is below.\n\t\tNote that if the trace buffer is exhausted, the checksum will\n\t\tstill continue to operate.\n\n\t\t\tiotrace is enabled\n\t\t\tStart:  10000000\t(buffer start address)\n\t\t\tSize:   00010000\t(buffer size)\n\t\t\tOffset: 00000120\t(current buffer offset)\n\t\t\tOutput: 10000120\t(start + offset)\n\t\t\tCount:  00000018\t(number of trace records)\n\t\t\tCRC32:  9526fb66\t(CRC32 of all trace records)\n\n- Timestamp Support:\n\n\t\tWhen CONFIG_TIMESTAMP is selected, the timestamp\n\t\t(date and time) of an image is printed by image\n\t\tcommands like bootm or iminfo. This option is\n\t\tautomatically enabled when you select CONFIG_CMD_DATE .\n\n- Partition Labels (disklabels) Supported:\n\t\tZero or more of the following:\n\t\tCONFIG_MAC_PARTITION   Apple's MacOS partition table.\n\t\tCONFIG_ISO_PARTITION   ISO partition table, used on CDROM etc.\n\t\tCONFIG_EFI_PARTITION   GPT partition table, common when EFI is the\n\t\t\t\t       bootloader.  Note 2TB partition limit; see\n\t\t\t\t       disk/part_efi.c\n\t\tCONFIG_SCSI) you must configure support for at\n\t\tleast one non-MTD partition type as well.\n\n- IDE Reset method:\n\t\tCONFIG_IDE_RESET_ROUTINE - this is defined in several\n\t\tboard configurations files but used nowhere!\n\n\t\tCONFIG_IDE_RESET - is this is defined, IDE Reset will\n\t\tbe performed by calling the function\n\t\t\tide_set_reset(int reset)\n\t\twhich has to be defined in a board specific file\n\n- ATAPI Support:\n\t\tCONFIG_ATAPI\n\n\t\tSet this to enable ATAPI support.\n\n- LBA48 Support\n\t\tCONFIG_LBA48\n\n\t\tSet this to enable support for disks larger than 137GB\n\t\tAlso look at CONFIG_SYS_64BIT_LBA.\n\t\tWhithout these , LBA48 support uses 32bit variables and will 'only'\n\t\tsupport disks up to 2.1TB.\n\n\t\tCONFIG_SYS_64BIT_LBA:\n\t\t\tWhen enabled, makes the IDE subsystem use 64bit sector addresses.\n\t\t\tDefault is 32bit.\n\n- SCSI Support:\n\t\tCONFIG_SYS_SCSI_MAX_LUN [8], CONFIG_SYS_SCSI_MAX_SCSI_ID [7] and\n\t\tCONFIG_SYS_SCSI_MAX_DEVICE [CONFIG_SYS_SCSI_MAX_SCSI_ID *\n\t\tCONFIG_SYS_SCSI_MAX_LUN] can be adjusted to define the\n\t\tmaximum numbers of LUNs, SCSI ID's and target\n\t\tdevices.\n\n\t\tThe environment variable 'scsidevs' is set to the number of\n\t\tSCSI devices found during the last scan.\n\n- NETWORK Support (PCI):\n\t\tCONFIG_E1000\n\t\tSupport for Intel 8254x/8257x gigabit chips.\n\n\t\tCONFIG_E1000_SPI\n\t\tUtility code for direct access to the SPI bus on Intel 8257x.\n\t\tThis does not do anything useful unless you set at least one\n\t\tof CONFIG_CMD_E1000 or CONFIG_E1000_SPI_GENERIC.\n\n\t\tCONFIG_E1000_SPI_GENERIC\n\t\tAllow generic access to the SPI bus on the Intel 8257x, for\n\t\texample with the \"sspi\" command.\n\n\t\tCONFIG_NATSEMI\n\t\tSupport for National dp83815 chips.\n\n\t\tCONFIG_NS8382X\n\t\tSupport for National dp8382[01] gigabit chips.\n\n- NETWORK Support (other):\n\n\t\tCONFIG_DRIVER_AT91EMAC\n\t\tSupport for AT91RM9200 EMAC.\n\n\t\t\tCONFIG_RMII\n\t\t\tDefine this to use reduced MII inteface\n\n\t\t\tCONFIG_DRIVER_AT91EMAC_QUIET\n\t\t\tIf this defined, the driver is quiet.\n\t\t\tThe driver doen't show link status messages.\n\n\t\tCONFIG_CALXEDA_XGMAC\n\t\tSupport for the Calxeda XGMAC device\n\n\t\tCONFIG_LAN91C96\n\t\tSupport for SMSC's LAN91C96 chips.\n\n\t\t\tCONFIG_LAN91C96_USE_32_BIT\n\t\t\tDefine this to enable 32 bit addressing\n\n\t\tCONFIG_SMC91111\n\t\tSupport for SMSC's LAN91C111 chip\n\n\t\t\tCONFIG_SMC91111_BASE\n\t\t\tDefine this to hold the physical address\n\t\t\tof the device (I/O space)\n\n\t\t\tCONFIG_SMC_USE_32_BIT\n\t\t\tDefine this if data bus is 32 bits\n\n\t\t\tCONFIG_SMC_USE_IOFUNCS\n\t\t\tDefine this to use i/o functions instead of macros\n\t\t\t(some hardware wont work with macros)\n\n\t\t\tCONFIG_SYS_DAVINCI_EMAC_PHY_COUNT\n\t\t\tDefine this if you have more then 3 PHYs.\n\n\t\tCONFIG_FTGMAC100\n\t\tSupport for Faraday's FTGMAC100 Gigabit SoC Ethernet\n\n\t\t\tCONFIG_FTGMAC100_EGIGA\n\t\t\tDefine this to use GE link update with gigabit PHY.\n\t\t\tDefine this if FTGMAC100 is connected to gigabit PHY.\n\t\t\tIf your system has 10/100 PHY only, it might not occur\n\t\t\twrong behavior. Because PHY usually return timeout or\n\t\t\tuseless data when polling gigabit status and gigabit\n\t\t\tcontrol registers. This behavior won't affect the\n\t\t\tcorrectnessof 10/100 link speed update.\n\n\t\tCONFIG_SH_ETHER\n\t\tSupport for Renesas on-chip Ethernet controller\n\n\t\t\tCONFIG_SH_ETHER_USE_PORT\n\t\t\tDefine the number of ports to be used\n\n\t\t\tCONFIG_SH_ETHER_PHY_ADDR\n\t\t\tDefine the ETH PHY's address\n\n\t\t\tCONFIG_SH_ETHER_CACHE_WRITEBACK\n\t\t\tIf this option is set, the driver enables cache flush.\n\n- TPM Support:\n\t\tCONFIG_TPM\n\t\tSupport TPM devices.\n\n\t\tCONFIG_TPM_TIS_INFINEON\n\t\tSupport for Infineon i2c bus TPM devices. Only one device\n\t\tper system is supported at this time.\n\n\t\t\tCONFIG_TPM_TIS_I2C_BURST_LIMITATION\n\t\t\tDefine the burst count bytes upper limit\n\n\t\tCONFIG_TPM_ST33ZP24\n\t\tSupport for STMicroelectronics TPM devices. Requires DM_TPM support.\n\n\t\t\tCONFIG_TPM_ST33ZP24_I2C\n\t\t\tSupport for STMicroelectronics ST33ZP24 I2C devices.\n\t\t\tRequires TPM_ST33ZP24 and I2C.\n\n\t\t\tCONFIG_TPM_ST33ZP24_SPI\n\t\t\tSupport for STMicroelectronics ST33ZP24 SPI devices.\n\t\t\tRequires TPM_ST33ZP24 and SPI.\n\n\t\tCONFIG_TPM_ATMEL_TWI\n\t\tSupport for Atmel TWI TPM device. Requires I2C support.\n\n\t\tCONFIG_TPM_TIS_LPC\n\t\tSupport for generic parallel port TPM devices. Only one device\n\t\tper system is supported at this time.\n\n\t\t\tCONFIG_TPM_TIS_BASE_ADDRESS\n\t\t\tBase address where the generic TPM device is mapped\n\t\t\tto. Contemporary x86 systems usually map it at\n\t\t\t0xfed40000.\n\n\t\tCONFIG_TPM\n\t\tDefine this to enable the TPM support library which provides\n\t\tfunctional interfaces to some TPM commands.\n\t\tRequires support for a TPM device.\n\n\t\tCONFIG_TPM_AUTH_SESSIONS\n\t\tDefine this to enable authorized functions in the TPM library.\n\t\tRequires CONFIG_TPM and CONFIG_SHA1.\n\n- USB Support:\n\t\tAt the moment only the UHCI host controller is\n\t\tsupported (PIP405, MIP405); define\n\t\tCONFIG_USB_UHCI to enable it.\n\t\tdefine CONFIG_USB_KEYBOARD to enable the USB Keyboard\n\t\tand define CONFIG_USB_STORAGE to enable the USB\n\t\tstorage devices.\n\t\tNote:\n\t\tSupported are USB Keyboards and USB Floppy drives\n\t\t(TEAC FD-05PUB).\n\n\t\tCONFIG_USB_EHCI_TXFIFO_THRESH enables setting of the\n\t\ttxfilltuning field in the EHCI controller on reset.\n\n\t\tCONFIG_USB_DWC2_REG_ADDR the physical CPU address of the DWC2\n\t\tHW module registers.\n\n- USB Device:\n\t\tDefine the below if you wish to use the USB console.\n\t\tOnce firmware is rebuilt from a serial console issue the\n\t\tcommand \"setenv stdin usbtty; setenv stdout usbtty\" and\n\t\tattach your USB cable. The Unix command \"dmesg\" should print\n\t\tit has found a new device. The environment variable usbtty\n\t\tcan be set to gserial or cdc_acm to enable your device to\n\t\tappear to a USB host as a Linux gserial device or a\n\t\tCommon Device Class Abstract Control Model serial device.\n\t\tIf you select usbtty = gserial you should be able to enumerate\n\t\ta Linux host by\n\t\t# modprobe usbserial vendor=0xVendorID product=0xProductID\n\t\telse if using cdc_acm, simply setting the environment\n\t\tvariable usbtty to be cdc_acm should suffice. The following\n\t\tmight be defined in YourBoardName.h\n\n\t\t\tCONFIG_USB_DEVICE\n\t\t\tDefine this to build a UDC device\n\n\t\t\tCONFIG_USB_TTY\n\t\t\tDefine this to have a tty type of device available to\n\t\t\ttalk to the UDC device\n\n\t\t\tCONFIG_USBD_HS\n\t\t\tDefine this to enable the high speed support for usb\n\t\t\tdevice and usbtty. If this feature is enabled, a routine\n\t\t\tint is_usbd_high_speed(void)\n\t\t\talso needs to be defined by the driver to dynamically poll\n\t\t\twhether the enumeration has succeded at high speed or full\n\t\t\tspeed.\n\n\t\t\tCONFIG_SYS_CONSOLE_IS_IN_ENV\n\t\t\tDefine this if you want stdin, stdout \u0026/or stderr to\n\t\t\tbe set to usbtty.\n\n\t\tIf you have a USB-IF assigned VendorID then you may wish to\n\t\tdefine your own vendor specific values either in BoardName.h\n\t\tor directly in usbd_vendor_info.h. If you don't define\n\t\tCONFIG_USBD_MANUFACTURER, CONFIG_USBD_PRODUCT_NAME,\n\t\tCONFIG_USBD_VENDORID and CONFIG_USBD_PRODUCTID, then U-Boot\n\t\tshould pretend to be a Linux device to it's target host.\n\n\t\t\tCONFIG_USBD_MANUFACTURER\n\t\t\tDefine this string as the name of your company for\n\t\t\t- CONFIG_USBD_MANUFACTURER \"my company\"\n\n\t\t\tCONFIG_USBD_PRODUCT_NAME\n\t\t\tDefine this string as the name of your product\n\t\t\t- CONFIG_USBD_PRODUCT_NAME \"acme usb device\"\n\n\t\t\tCONFIG_USBD_VENDORID\n\t\t\tDefine this as your assigned Vendor ID from the USB\n\t\t\tImplementors Forum. This *must* be a genuine Vendor ID\n\t\t\tto avoid polluting the USB namespace.\n\t\t\t- CONFIG_USBD_VENDORID 0xFFFF\n\n\t\t\tCONFIG_USBD_PRODUCTID\n\t\t\tDefine this as the unique Product ID\n\t\t\tfor your device\n\t\t\t- CONFIG_USBD_PRODUCTID 0xFFFF\n\n- ULPI Layer Support:\n\t\tThe ULPI (UTMI Low Pin (count) Interface) PHYs are supported via\n\t\tthe generic ULPI layer. The generic layer accesses the ULPI PHY\n\t\tvia the platform viewport, so you need both the genric layer and\n\t\tthe viewport enabled. Currently only Chipidea/ARC based\n\t\tviewport is supported.\n\t\tTo enable the ULPI layer support, define CONFIG_USB_ULPI and\n\t\tCONFIG_USB_ULPI_VIEWPORT in your board configuration file.\n\t\tIf your ULPI phy needs a different reference clock than the\n\t\tstandard 24 MHz then you have to define CONFIG_ULPI_REF_CLK to\n\t\tthe appropriate value in Hz.\n\n- MMC Support:\n\t\tThe MMC controller on the Intel PXA is supported. To\n\t\tenable this define CONFIG_MMC. The MMC can be\n\t\taccessed from the boot prompt by mapping the device\n\t\tto physical memory similar to flash. Command line is\n\t\tenabled with CONFIG_CMD_MMC. The MMC driver also works with\n\t\tthe FAT fs. This is enabled with CONFIG_CMD_FAT.\n\n\t\tCONFIG_SH_MMCIF\n\t\tSupport for Renesas on-chip MMCIF controller\n\n\t\t\tCONFIG_SH_MMCIF_ADDR\n\t\t\tDefine the base address of MMCIF registers\n\n\t\t\tCONFIG_SH_MMCIF_CLK\n\t\t\tDefine the clock frequency for MMCIF\n\n- USB Device Firmware Update (DFU) class support:\n\t\tCONFIG_DFU_OVER_USB\n\t\tThis enables the USB portion of the DFU USB class\n\n\t\tCONFIG_DFU_NAND\n\t\tThis enables support for exposing NAND devices via DFU.\n\n\t\tCONFIG_DFU_RAM\n\t\tThis enables support for exposing RAM via DFU.\n\t\tNote: DFU spec refer to non-volatile memory usage, but\n\t\tallow usages beyond the scope of spec - here RAM usage,\n\t\tone that would help mostly the developer.\n\n\t\tCONFIG_SYS_DFU_DATA_BUF_SIZE\n\t\tDfu transfer uses a buffer before writing data to the\n\t\traw storage device. Make the size (in bytes) of this buffer\n\t\tconfigurable. The size of this buffer is also configurable\n\t\tthrough the \"dfu_bufsiz\" environment variable.\n\n\t\tCONFIG_SYS_DFU_MAX_FILE_SIZE\n\t\tWhen updating files rather than the raw storage device,\n\t\twe use a static buffer to copy the file into and then write\n\t\tthe buffer once we've been given the whole file.  Define\n\t\tthis to the maximum filesize (in bytes) for the buffer.\n\t\tDefault is 4 MiB if undefined.\n\n\t\tDFU_DEFAULT_POLL_TIMEOUT\n\t\tPoll timeout [ms], is the timeout a device can send to the\n\t\thost. The host must wait for this timeout before sending\n\t\ta subsequent DFU_GET_STATUS request to the device.\n\n\t\tDFU_MANIFEST_POLL_TIMEOUT\n\t\tPoll timeout [ms], which the device sends to the host when\n\t\tentering dfuMANIFEST state. Host waits this timeout, before\n\t\tsending again an USB request to the device.\n\n- Journaling Flash filesystem support:\n\t\tCONFIG_JFFS2_NAND\n\t\tDefine these for a default partition on a NAND device\n\n\t\tCONFIG_SYS_JFFS2_FIRST_SECTOR,\n\t\tCONFIG_SYS_JFFS2_FIRST_BANK, CONFIG_SYS_JFFS2_NUM_BANKS\n\t\tDefine these for a default partition on a NOR device\n\n- Keyboard Support:\n\t\tSee Kconfig help for available keyboard drivers.\n\n\t\tCONFIG_KEYBOARD\n\n\t\tDefine this to enable a custom keyboard support.\n\t\tThis simply calls drv_keyboard_init() which must be\n\t\tdefined in your board-specific files. This option is deprecated\n\t\tand is only used by novena. For new boards, use driver model\n\t\tinstead.\n\n- Video support:\n\t\tCONFIG_FSL_DIU_FB\n\t\tEnable the Freescale DIU video driver.\tReference boards for\n\t\tSOCs that have a DIU should define this macro to enable DIU\n\t\tsupport, and should also define these other macros:\n\n\t\t\tCONFIG_SYS_DIU_ADDR\n\t\t\tCONFIG_VIDEO\n\t\t\tCONFIG_CFB_CONSOLE\n\t\t\tCONFIG_VIDEO_SW_CURSOR\n\t\t\tCONFIG_VGA_AS_SINGLE_DEVICE\n\t\t\tCONFIG_VIDEO_LOGO\n\t\t\tCONFIG_VIDEO_BMP_LOGO\n\n\t\tThe DIU driver will look for the 'video-mode' environment\n\t\tvariable, and if defined, enable the DIU as a console during\n\t\tboot.  See the documentation file doc/README.video for a\n\t\tdescription of this variable.\n\n- LCD Support:\tCONFIG_LCD\n\n\t\tDefine this to enable LCD support (for output to LCD\n\t\tdisplay); also select one of the supported displays\n\t\tby defining one of these:\n\n\t\tCONFIG_ATMEL_LCD:\n\n\t\t\tHITACHI TX09D70VM1CCA, 3.5\", 240x320.\n\n\t\tCONFIG_NEC_NL6448AC33:\n\n\t\t\tNEC NL6448AC33-18. Active, color, single scan.\n\n\t\tCONFIG_NEC_NL6448BC20\n\n\t\t\tNEC NL6448BC20-08. 6.5\", 640x480.\n\t\t\tActive, color, single scan.\n\n\t\tCONFIG_NEC_NL6448BC33_54\n\n\t\t\tNEC NL6448BC33-54. 10.4\", 640x480.\n\t\t\tActive, color, single scan.\n\n\t\tCONFIG_SHARP_16x9\n\n\t\t\tSharp 320x240. Active, color, single scan.\n\t\t\tIt isn't 16x9, and I am not sure what it is.\n\n\t\tCONFIG_SHARP_LQ64D341\n\n\t\t\tSharp LQ64D341 display, 640x480.\n\t\t\tActive, color, single scan.\n\n\t\tCONFIG_HLD1045\n\n\t\t\tHLD1045 display, 640x480.\n\t\t\tActive, color, single scan.\n\n\t\tCONFIG_OPTREX_BW\n\n\t\t\tOptrex\t CBL50840-2 NF-FW 99 22 M5\n\t\t\tor\n\t\t\tHitachi\t LMG6912RPFC-00T\n\t\t\tor\n\t\t\tHitachi\t SP14Q002\n\n\t\t\t320x240. Black \u0026 white.\n\n\t\tCONFIG_LCD_ALIGNMENT\n\n\t\tNormally the LCD is page-aligned (typically 4KB). If this is\n\t\tdefined then the LCD will be aligned to this value instead.\n\t\tFor ARM it is sometimes useful to use MMU_SECTION_SIZE\n\t\there, since it is cheaper to change data cache settings on\n\t\ta per-section basis.\n\n\n\t\tCONFIG_LCD_ROTATION\n\n\t\tSometimes, for example if the display is mounted in portrait\n\t\tmode or even if it's mounted landscape but rotated by 180degree,\n\t\twe need to rotate our content of the display relative to the\n\t\tframebuffer, so that user can read the messages which are\n\t\tprinted out.\n\t\tOnce CONFIG_LCD_ROTATION is defined, the lcd_console will be\n\t\tinitialized with a given rotation from \"vl_rot\" out of\n\t\t\"vidinfo_t\" which is provided by the board specific code.\n\t\tThe value for vl_rot is coded as following (matching to\n\t\tfbcon=rotate:\u003cn\u003e linux-kernel commandline):\n\t\t0 = no rotation respectively 0 degree\n\t\t1 = 90 degree rotation\n\t\t2 = 180 degree rotation\n\t\t3 = 270 degree rotation\n\n\t\tIf CONFIG_LCD_ROTATION is not defined, the console will be\n\t\tinitialized with 0degree rotation.\n\n\t\tCONFIG_LCD_BMP_RLE8\n\n\t\tSupport drawing of RLE8-compressed bitmaps on the LCD.\n\n\t\tCONFIG_I2C_EDID\n\n\t\tEnables an 'i2c edid' command which can read EDID\n\t\tinformation over I2C from an attached LCD display.\n\n- MII/PHY support:\n\t\tCONFIG_PHY_CLOCK_FREQ (ppc4xx)\n\n\t\tThe clock frequency of the MII bus\n\n\t\tCONFIG_PHY_RESET_DELAY\n\n\t\tSome PHY like Intel LXT971A need extra delay after\n\t\treset before any MII register access is possible.\n\t\tFor such PHY, set this option to the usec delay\n\t\trequired. (minimum 300usec for LXT971A)\n\n\t\tCONFIG_PHY_CMD_DELAY (ppc4xx)\n\n\t\tSome PHY like Intel LXT971A need extra delay after\n\t\tcommand issued before MII status register can be read\n\n- IP address:\n\t\tCONFIG_IPADDR\n\n\t\tDefine a default value for the IP address to use for\n\t\tthe default Ethernet interface, in case this is not\n\t\tdetermined through e.g. bootp.\n\t\t(Environment variable \"ipaddr\")\n\n- Server IP address:\n\t\tCONFIG_SERVERIP\n\n\t\tDefines a default value for the IP address of a TFTP\n\t\tserver to contact when using the \"tftboot\" command.\n\t\t(Environment variable \"serverip\")\n\n\t\tCONFIG_KEEP_SERVERADDR\n\n\t\tKeeps the server's MAC address, in the env 'serveraddr'\n\t\tfor passing to bootargs (like Linux's netconsole option)\n\n- Gateway IP address:\n\t\tCONFIG_GATEWAYIP\n\n\t\tDefines a default value for the IP address of the\n\t\tdefault router where packets to other networks are\n\t\tsent to.\n\t\t(Environment variable \"gatewayip\")\n\n- Subnet mask:\n\t\tCONFIG_NETMASK\n\n\t\tDefines a default value for the subnet mask (or\n\t\trouting prefix) which is used to determine if an IP\n\t\taddress belongs to the local subnet or needs to be\n\t\tforwarded through a router.\n\t\t(Environment variable \"netmask\")\n\n- BOOTP Recovery Mode:\n\t\tCONFIG_BOOTP_RANDOM_DELAY\n\n\t\tIf you have many targets in a network that try to\n\t\tboot using BOOTP, you may want to avoid that all\n\t\tsystems send out BOOTP requests at precisely the same\n\t\tmoment (which would happen for instance at recovery\n\t\tfrom a power failure, when all systems will try to\n\t\tboot, thus flooding the BOOTP server. Defining\n\t\tCONFIG_BOOTP_RANDOM_DELAY causes a random delay to be\n\t\tinserted before sending out BOOTP requests. The\n\t\tfollowing delays are inserted then:\n\n\t\t1st BOOTP request:\tdelay 0 ... 1 sec\n\t\t2nd BOOTP request:\tdelay 0 ... 2 sec\n\t\t3rd BOOTP request:\tdelay 0 ... 4 sec\n\t\t4th and following\n\t\tBOOTP requests:\t\tdelay 0 ... 8 sec\n\n\t\tCONFIG_BOOTP_ID_CACHE_SIZE\n\n\t\tBOOTP packets are uniquely identified using a 32-bit ID. The\n\t\tserver will copy the ID from client requests to responses and\n\t\tU-Boot will use this to determine if it is the destination of\n\t\tan incoming response. Some servers will check that addresses\n\t\taren't in use before handing them out (usually using an ARP\n\t\tping) and therefore take up to a few hundred milliseconds to\n\t\trespond. Network congestion may also influence the time it\n\t\ttakes for a response to make it back to the client. If that\n\t\ttime is too long, U-Boot will retransmit requests. In order\n\t\tto allow earlier responses to still be accepted after these\n\t\tretransmissions, U-Boot's BOOTP client keeps a small cache of\n\t\tIDs. The CONFIG_BOOTP_ID_CACHE_SIZE controls the size of this\n\t\tcache. The default is to keep IDs for up to four outstanding\n\t\trequests. Increasing this will allow U-Boot to accept offers\n\t\tfrom a BOOTP client in networks with unusually high latency.\n\n- DHCP Advanced Options:\n\t\tYou can fine tune the DHCP functionality by defining\n\t\tCONFIG_BOOTP_* symbols:\n\n\t\tCONFIG_BOOTP_NISDOMAIN\n\t\tCONFIG_BOOTP_BOOTFILESIZE\n\t\tCONFIG_BOOTP_NTPSERVER\n\t\tCONFIG_BOOTP_TIMEOFFSET\n\t\tCONFIG_BOOTP_VENDOREX\n\t\tCONFIG_BOOTP_MAY_FAIL\n\n\t\tCONFIG_BOOTP_SERVERIP - TFTP server will be the serverip\n\t\tenvironment variable, not the BOOTP server.\n\n\t\tCONFIG_BOOTP_MAY_FAIL - If the DHCP server is not found\n\t\tafter the configured retry count, the call will fail\n\t\tinstead of starting over.  This can be used to fail over\n\t\tto Link-local IP address configuration if the DHCP server\n\t\tis not available.\n\n\t\tCONFIG_BOOTP_DHCP_REQUEST_DELAY\n\n\t\tA 32bit value in microseconds for a delay between\n\t\treceiving a \"DHCP Offer\" and sending the \"DHCP Request\".\n\t\tThis fixes a problem with certain DHCP servers that don't\n\t\trespond 100% of the time to a \"DHCP request\". E.g. On an\n\t\tAT91RM9200 processor running at 180MHz, this delay needed\n\t\tto be *at least* 15,000 usec before a Windows Server 2003\n\t\tDHCP server would reply 100% of the time. I recommend at\n\t\tleast 50,000 usec to be safe. The alternative is to hope\n\t\tthat one of the retries will be successful but note that\n\t\tthe DHCP timeout and retry process takes a longer than\n\t\tthis delay.\n\n - Link-local IP address negotiation:\n\t\tNegotiate with other link-local clients on the local network\n\t\tfor an address that doesn't require explicit configuration.\n\t\tThis is especially useful if a DHCP server cannot be guaranteed\n\t\tto exist in all environments that the device must operate.\n\n\t\tSee doc/README.link-local for more information.\n\n - MAC address from environment variables\n\n\t\tFDT_SEQ_MACADDR_FROM_ENV\n\n\t\tFix-up device tree with MAC addresses fetched sequentially from\n\t\tenvironment variables. This config work on assumption that\n\t\tnon-usable ethernet node of device-tree are either not present\n\t\tor their status has been marked as \"disabled\".\n\n - CDP Options:\n\t\tCONFIG_CDP_DEVICE_ID\n\n\t\tThe device id used in CDP trigger frames.\n\n\t\tCONFIG_CDP_DEVICE_ID_PREFIX\n\n\t\tA two character string which is prefixed to the MAC address\n\t\tof the device.\n\n\t\tCONFIG_CDP_PORT_ID\n\n\t\tA printf format string which contains the ascii name of\n\t\tthe port. Normally is set to \"eth%d\" which sets\n\t\teth0 for the first Ethernet, eth1 for the second etc.\n\n\t\tCONFIG_CDP_CAPABILITIES\n\n\t\tA 32bit integer which indicates the device capabilities;\n\t\t0x00000010 for a normal host which does not forwards.\n\n\t\tCONFIG_CDP_VERSION\n\n\t\tAn ascii string containing the version of the software.\n\n\t\tCONFIG_CDP_PLATFORM\n\n\t\tAn ascii string containing the name of the platform.\n\n\t\tCONFIG_CDP_TRIGGER\n\n\t\tA 32bit integer sent on the trigger.\n\n\t\tCONFIG_CDP_POWER_CONSUMPTION\n\n\t\tA 16bit integer containing the power consumption of the\n\t\tdevice in .1 of milliwatts.\n\n\t\tCONFIG_CDP_APPLIANCE_VLAN_TYPE\n\n\t\tA byte containing the id of the VLAN.\n\n- Status LED:\tCONFIG_LED_STATUS\n\n\t\tSeveral configurations allow to display the current\n\t\tstatus using a LED. For instance, the LED will blink\n\t\tfast while running U-Boot code, stop blinking as\n\t\tsoon as a reply to a BOOTP request was received, and\n\t\tstart blinking slow once the Linux kernel is running\n\t\t(supported by a status LED driver in the Linux\n\t\tkernel). Defining CONFIG_LED_STATUS enables this\n\t\tfeature in U-Boot.\n\n\t\tAdditional options:\n\n\t\tCONFIG_LED_STATUS_GPIO\n\t\tThe status LED can be connected to a GPIO pin.\n\t\tIn such cases, the gpio_led driver can be used as a\n\t\tstatus LED backend implementation. Define CONFIG_LED_STATUS_GPIO\n\t\tto include the gpio_led driver in the U-Boot binary.\n\n\t\tCONFIG_GPIO_LED_INVERTED_TABLE\n\t\tSome GPIO connected LEDs may have inverted polarity in which\n\t\tcase the GPIO high value corresponds to LED off state and\n\t\tGPIO low value corresponds to LED on state.\n\t\tIn such cases CONFIG_GPIO_LED_INVERTED_TABLE may be defined\n\t\twith a list of GPIO LEDs that have inverted polarity.\n\n- I2C Support:\tCONFIG_SYS_I2C\n\n\t\tThis enable the NEW i2c subsystem, and will allow you to use\n\t\ti2c commands at the u-boot command line (as long as you set\n\t\t    CONFIG_SYS_I2C_SOFT_SPEED and CONFIG_SYS_I2C_SOFT_SLAVE\n\t\t    for defining speed and slave address\n\t\t  - activate second bus with I2C_SOFT_DECLARATIONS2 define\n\t\t    CONFIG_SYS_I2C_SOFT_SPEED_2 and CONFIG_SYS_I2C_SOFT_SLAVE_2\n\t\t    for defining speed and slave address\n\t\t  - activate third bus with I2C_SOFT_DECLARATIONS3 define\n\t\t    CONFIG_SYS_I2C_SOFT_SPEED_3 and CONFIG_SYS_I2C_SOFT_SLAVE_3\n\t\t    for defining speed and slave address\n\t\t  - activate fourth bus with I2C_SOFT_DECLARATIONS4 define\n\t\t    CONFIG_SYS_I2C_SOFT_SPEED_4 and CONFIG_SYS_I2C_SOFT_SLAVE_4\n\t\t    for defining speed and slave address\n\n\t\t- drivers/i2c/fsl_i2c.c:\n\t\t  - activate i2c driver with CONFIG_SYS_I2C_FSL\n\t\t    define CONFIG_SYS_FSL_I2C_OFFSET for setting the register\n\t\t    offset CONFIG_SYS_FSL_I2C_SPEED for the i2c speed and\n\t\t    CONFIG_SYS_FSL_I2C_SLAVE for the slave addr of the first\n\t\t    bus.\n\t\t  - If your board supports a second fsl i2c bus, define\n\t\t    CONFIG_SYS_FSL_I2C2_OFFSET for the register offset\n\t\t    CONFIG_SYS_FSL_I2C2_SPEED for the speed and\n\t\t    CONFIG_SYS_FSL_I2C2_SLAVE for the slave address of the\n\t\t    second bus.\n\n\t\t- drivers/i2c/tegra_i2c.c:\n\t\t  - activate this driver with CONFIG_SYS_I2C_TEGRA\n\t\t  - This driver adds 4 i2c buses with a fix speed from\n\t\t    100000 and the slave addr 0!\n\n\t\t- drivers/i2c/ppc4xx_i2c.c\n\t\t  - activate this driver with CONFIG_SYS_I2C_PPC4XX\n\t\t  - CONFIG_SYS_I2C_PPC4XX_CH0 activate hardware channel 0\n\t\t  - CONFIG_SYS_I2C_PPC4XX_CH1 activate hardware channel 1\n\n\t\t- drivers/i2c/i2c_mxc.c\n\t\t  - activate this driver with CONFIG_SYS_I2C_MXC\n\t\t  - enable bus 1 with CONFIG_SYS_I2C_MXC_I2C1\n\t\t  - enable bus 2 with CONFIG_SYS_I2C_MXC_I2C2\n\t\t  - enable bus 3 with CONFIG_SYS_I2C_MXC_I2C3\n\t\t  - enable bus 4 with CONFIG_SYS_I2C_MXC_I2C4\n\t\t  - define speed for bus 1 with CONFIG_SYS_MXC_I2C1_SPEED\n\t\t  - define slave for bus 1 with CONFIG_SYS_MXC_I2C1_SLAVE\n\t\t  - define speed for bus 2 with CONFIG_SYS_MXC_I2C2_SPEED\n\t\t  - define slave for bus 2 with CONFIG_SYS_MXC_I2C2_SLAVE\n\t\t  - define speed for bus 3 with CONFIG_SYS_MXC_I2C3_SPEED\n\t\t  - define slave for bus 3 with CONFIG_SYS_MXC_I2C3_SLAVE\n\t\t  - define speed for bus 4 with CONFIG_SYS_MXC_I2C4_SPEED\n\t\t  - define slave for bus 4 with CONFIG_SYS_MXC_I2C4_SLAVE\n\t\tIf those defines are not set, default value is 100000\n\t\tfor speed, and 0 for slave.\n\n\t\t- drivers/i2c/rcar_i2c.c:\n\t\t  - activate this driver with CONFIG_SYS_I2C_RCAR\n\t\t  - This driver adds 4 i2c buses\n\n\t\t- drivers/i2c/sh_i2c.c:\n\t\t  - activate this driver with CONFIG_SYS_I2C_SH\n\t\t  - This driver adds from 2 to 5 i2c buses\n\n\t\t  - CONFIG_SYS_I2C_SH_BASE0 for setting the register channel 0\n\t\t  - CONFIG_SYS_I2C_SH_SPEED0 for for the speed channel 0\n\t\t  - CONFIG_SYS_I2C_SH_BASE1 for setting the register channel 1\n\t\t  - CONFIG_SYS_I2C_SH_SPEED1 for for the speed channel 1\n\t\t  - CONFIG_SYS_I2C_SH_BASE2 for setting the register channel 2\n\t\t  - CONFIG_SYS_I2C_SH_SPEED2 for for the speed channel 2\n\t\t  - CONFIG_SYS_I2C_SH_BASE3 for setting the register channel 3\n\t\t  - CONFIG_SYS_I2C_SH_SPEED3 for for the speed channel 3\n\t\t  - CONFIG_SYS_I2C_SH_BASE4 for setting the register channel 4\n\t\t  - CONFIG_SYS_I2C_SH_SPEED4 for for the speed channel 4\n\t\t  - CONFIG_SYS_I2C_SH_NUM_CONTROLLERS for number of i2c buses\n\n\t\t- drivers/i2c/omap24xx_i2c.c\n\t\t  - activate this driver with CONFIG_SYS_I2C_OMAP24XX\n\t\t  - CONFIG_SYS_OMAP24_I2C_SPEED speed channel 0\n\t\t  - CONFIG_SYS_OMAP24_I2C_SLAVE slave addr channel 0\n\t\t  - CONFIG_SYS_OMAP24_I2C_SPEED1 speed channel 1\n\t\t  - CONFIG_SYS_OMAP24_I2C_SLAVE1 slave addr channel 1\n\t\t  - CONFIG_SYS_OMAP24_I2C_SPEED2 speed channel 2\n\t\t  - CONFIG_SYS_OMAP24_I2C_SLAVE2 slave addr channel 2\n\t\t  - CONFIG_SYS_OMAP24_I2C_SPEED3 speed channel 3\n\t\t  - CONFIG_SYS_OMAP24_I2C_SLAVE3 slave addr channel 3\n\t\t  - CONFIG_SYS_OMAP24_I2C_SPEED4 speed channel 4\n\t\t  - CONFIG_SYS_OMAP24_I2C_SLAVE4 slave addr channel 4\n\n\t\t- drivers/i2c/s3c24x0_i2c.c:\n\t\t  - activate this driver with CONFIG_SYS_I2C_S3C24X0\n\t\t  - This driver adds i2c buses (11 for Exynos5250, Exynos5420\n\t\t    9 i2c buses for Exynos4 and 1 for S3C24X0 SoCs from Samsung)\n\t\t    with a fix speed from 100000 and the slave addr 0!\n\n\t\t- drivers/i2c/ihs_i2c.c\n\t\t  - activate this driver with CONFIG_SYS_I2C_IHS\n\t\t  - CONFIG_SYS_I2C_IHS_CH0 activate hardware channel 0\n\t\t  - CONFIG_SYS_I2C_IHS_SPEED_0 speed channel 0\n\t\t  - CONFIG_SYS_I2C_IHS_SLAVE_0 slave addr channel 0\n\t\t  - CONFIG_SYS_I2C_IHS_CH1 activate hardware channel 1\n\t\t  - CONFIG_SYS_I2C_IHS_SPEED_1 speed channel 1\n\t\t  - CONFIG_SYS_I2C_IHS_SLAVE_1 slave addr channel 1\n\t\t  - CONFIG_SYS_I2C_IHS_CH2 activate hardware channel 2\n\t\t  - CONFIG_SYS_I2C_IHS_SPEED_2 speed channel 2\n\t\t  - CONFIG_SYS_I2C_IHS_SLAVE_2 slave addr channel 2\n\t\t  - CONFIG_SYS_I2C_IHS_CH3 activate hardware channel 3\n\t\t  - CONFIG_SYS_I2C_IHS_SPEED_3 speed channel 3\n\t\t  - CONFIG_SYS_I2C_IHS_SLAVE_3 slave addr channel 3\n\t\t  - activate dual channel with CONFIG_SYS_I2C_IHS_DUAL\n\t\t  - CONFIG_SYS_I2C_IHS_SPEED_0_1 speed channel 0_1\n\t\t  - CONFIG_SYS_I2C_IHS_SLAVE_0_1 slave addr channel 0_1\n\t\t  - CONFIG_SYS_I2C_IHS_SPEED_1_1 speed channel 1_1\n\t\t  - CONFIG_SYS_I2C_IHS_SLAVE_1_1 slave addr channel 1_1\n\t\t  - CONFIG_SYS_I2C_IHS_SPEED_2_1 speed channel 2_1\n\t\t  - CONFIG_SYS_I2C_IHS_SLAVE_2_1 slave addr channel 2_1\n\t\t  - CONFIG_SYS_I2C_IHS_SPEED_3_1 speed channel 3_1\n\t\t  - CONFIG_SYS_I2C_IHS_SLAVE_3_1 slave addr channel 3_1\n\n\t\tadditional defines:\n\n\t\tCONFIG_SYS_NUM_I2C_BUSES\n\t\tHold the number of i2c buses you want to use.\n\n\t\tCONFIG_SYS_I2C_DIRECT_BUS\n\t\tdefine this, if you don't use i2c muxes on your hardware.\n\t\tif CONFIG_SYS_I2C_MAX_HOPS is not defined or == 0 you can\n\t\tomit this define.\n\n\t\tCONFIG_SYS_I2C_MAX_HOPS\n\t\tdefine how many muxes are maximal consecutively connected\n\t\ton one i2c bus. If you not use i2c muxes, omit this\n\t\tdefine.\n\n\t\tCONFIG_SYS_I2C_BUSES\n\t\thold a list of buses you want to use, only used if\n\t\tCONFIG_SYS_I2C_DIRECT_BUS is not defined, for example\n\t\ta board with CONFIG_SYS_I2C_MAX_HOPS = 1 and\n\t\tCONFIG_SYS_NUM_I2C_BUSES = 9:\n\n\t\t CONFIG_SYS_I2C_BUSES\t{{0, {I2C_NULL_HOP}}, \\\n\t\t\t\t\t{0, {{I2C_MUX_PCA9547, 0x70, 1}}}, \\\n\t\t\t\t\t{0, {{I2C_MUX_PCA9547, 0x70, 2}}}, \\\n\t\t\t\t\t{0, {{I2C_MUX_PCA9547, 0x70, 3}}}, \\\n\t\t\t\t\t{0, {{I2C_MUX_PCA9547, 0x70, 4}}}, \\\n\t\t\t\t\t{0, {{I2C_MUX_PCA9547, 0x70, 5}}}, \\\n\t\t\t\t\t{1, {I2C_NULL_HOP}}, \\\n\t\t\t\t\t{1, {{I2C_MUX_PCA9544, 0x72, 1}}}, \\\n\t\t\t\t\t{1, {{I2C_MUX_PCA9544, 0x72, 2}}}, \\\n\t\t\t\t\t}\n\n\t\twhich defines\n\t\t\tbus 0 on adapter 0 without a mux\n\t\t\tbus 1 on adapter 0 with a PCA9547 on address 0x70 port 1\n\t\t\tbus 2 on adapter 0 with a PCA9547 on address 0x70 port 2\n\t\t\tbus 3 on adapter 0 with a PCA9547 on address 0x70 port 3\n\t\t\tbus 4 on adapter 0 with a PCA9547 on address 0x70 port 4\n\t\t\tbus 5 on adapter 0 with a PCA9547 on address 0x70 port 5\n\t\t\tbus 6 on adapter 1 without a mux\n\t\t\tbus 7 on adapter 1 with a PCA9544 on address 0x72 port 1\n\t\t\tbus 8 on adapter 1 with a PCA9544 on address 0x72 port 2\n\n\t\tIf you do not have i2c muxes on your board, omit this define.\n\n- Legacy I2C Support:\n\t\tIf you use the software i2c interface (CONFIG_SYS_I2C_SOFT)\n\t\tthen the following macros need to be defined (examples are\n\t\tfrom include/configs/lwmon.h):\n\n\t\tI2C_INIT\n\n\t\t(Optional). Any commands necessary to enable the I2C\n\t\tcontroller or configure ports.\n\n\t\teg: #define I2C_INIT (immr-\u003eim_cpm.cp_pbdir |=\tPB_SCL)\n\n\t\tI2C_ACTIVE\n\n\t\tThe code necessary to make the I2C data line active\n\t\t(driven).  If the data line is open collector, this\n\t\tdefine can be null.\n\n\t\teg: #define I2C_ACTIVE (immr-\u003eim_cpm.cp_pbdir |=  PB_SDA)\n\n\t\tI2C_TRISTATE\n\n\t\tThe code necessary to make the I2C data line tri-stated\n\t\t(inactive).  If the data line is open collector, this\n\t\tdefine can be null.\n\n\t\teg: #define I2C_TRISTATE (immr-\u003eim_cpm.cp_pbdir \u0026= ~PB_SDA)\n\n\t\tI2C_READ\n\n\t\tCode that returns true if the I2C data line is high,\n\t\tfalse if it is low.\n\n\t\teg: #define I2C_READ ((immr-\u003eim_cpm.cp_pbdat \u0026 PB_SDA) != 0)\n\n\t\tI2C_SDA(bit)\n\n\t\tIf \u003cbit\u003e is true, sets the I2C data line high. If it\n\t\tis false, it clears it (low).\n\n\t\teg: #define I2C_SDA(bit) \\\n\t\t\tif(bit) immr-\u003eim_cpm.cp_pbdat |=  PB_SDA; \\\n\t\t\telse\timmr-\u003eim_cpm.cp_pbdat \u0026= ~PB_SDA\n\n\t\tI2C_SCL(bit)\n\n\t\tIf \u003cbit\u003e is true, sets the I2C clock line high. If it\n\t\tis false, it clears it (low).\n\n\t\teg: #define I2C_SCL(bit) \\\n\t\t\tif(bit) immr-\u003eim_cpm.cp_pbdat |=  PB_SCL; \\\n\t\t\telse\timmr-\u003eim_cpm.cp_pbdat \u0026= ~PB_SCL\n\n\t\tI2C_DELAY\n\n\t\tThis delay is invoked four times per clock cycle so this\n\t\tcontrols the rate of data transfer.  The data rate thus\n\t\tis 1 / (I2C_DELAY * 4). Often defined to be something\n\t\tlike:\n\n\t\t#define I2C_DELAY  udelay(2)\n\n\t\tCONFIG_SOFT_I2C_GPIO_SCL / CONFIG_SOFT_I2C_GPIO_SDA\n\n\t\tIf your arch supports the generic GPIO framework (asm/gpio.h),\n\t\tthen you may alternatively define the two GPIOs that are to be\n\t\tused as SCL / SDA.  Any of the previous I2C_xxx macros will\n\t\thave GPIO-based defaults assigned to them as appropriate.\n\n\t\tYou should define these to the GPIO value as given directly to\n\t\tthe generic GPIO functions.\n\n\t\tCONFIG_SYS_I2C_INIT_BOARD\n\n\t\tWhen a board is reset during an i2c bus transfer\n\t\tchips might think that the current transfer is still\n\t\tin progress. On some boards it is possible to access\n\t\tthe i2c SCLK line directly, either by using the\n\t\tprocessor pin as a GPIO or by having a second pin\n\t\tconnected to the bus. If this option is defined a\n\t\tcustom i2c_init_board() routine in boards/xxx/board.c\n\t\tis run early in the boot sequence.\n\n\t\tCONFIG_I2C_MULTI_BUS\n\n\t\tThis option allows the use of multiple I2C buses, each of which\n\t\tmust have a controller.\t At any point in time, only one bus is\n\t\tactive.\t To switch to a different bus, use the 'i2c dev' command.\n\t\tNote that bus numbering is zero-based.\n\n\t\tCONFIG_SYS_I2C_NOPROBES\n\n\t\tThis option specifies a list of I2C devices that will be skipped\n\t\twhen the 'i2c probe' command is issued.\t If CONFIG_I2C_MULTI_BUS\n\t\tis set, specify a list of bus-device pairs.  Otherwise, specify\n\t\ta 1D array of device addresses\n\n\t\te.g.\n\t\t\t#undef\tCONFIG_I2C_MULTI_BUS\n\t\t\t#define CONFIG_SYS_I2C_NOPROBES {0x50,0x68}\n\n\t\twill skip addresses 0x50 and 0x68 on a board with one I2C bus\n\n\t\t\t#define CONFIG_I2C_MULTI_BUS\n\t\t\t#define CONFIG_SYS_I2C_NOPROBES\t{{0,0x50},{0,0x68},{1,0x54}}\n\n\t\twill skip addresses 0x50 and 0x68 on bus 0 and address 0x54 on bus 1\n\n\t\tCONFIG_SYS_SPD_BUS_NUM\n\n\t\tIf defined, then this indicates the I2C bus number for DDR SPD.\n\t\tIf not defined, then U-Boot assumes that SPD is on I2C bus 0.\n\n\t\tCONFIG_SYS_RTC_BUS_NUM\n\n\t\tIf defined, then this indicates the I2C bus number for the RTC.\n\t\tIf not defined, then U-Boot assumes that RTC is on I2C bus 0.\n\n\t\tCONFIG_SOFT_I2C_READ_REPEATED_START\n\n\t\tdefining this will force the i2c_read() function in\n\t\tthe soft_i2c driver to perform an I2C repeated start\n\t\tbetween writing the address pointer and reading the\n\t\tdata.  If this define is omitted the default behaviour\n\t\tof doing a stop-start sequence will be used.  Most I2C\n\t\tdevices can use either method, but some require one or\n\t\tthe other.\n\n- SPI Support:\tCONFIG_SPI\n\n\t\tEnables SPI driver (so far only tested with\n\t\tSPI EEPROM, also an instance works with Crystal A/D and\n\t\tD/As on the SACSng board)\n\n\t\tCONFIG_SOFT_SPI\n\n\t\tEnables a software (bit-bang) SPI driver rather than\n\t\tusing hardware support. This is a general purpose\n\t\tdriver that only requires three general I/O port pins\n\t\t(two outputs, one input) to function. If this is\n\t\tdefined, the board configuration must define several\n\t\tSPI configuration items (port pins to use, etc). For\n\t\tan example, see include/configs/sacsng.h.\n\n\t\tCONFIG_SYS_SPI_MXC_WAIT\n\t\tTimeout for waiting until spi transfer completed.\n\t\tdefault: (CONFIG_SYS_HZ/100)     /* 10 ms */\n\n- FPGA Support: CONFIG_FPGA\n\n\t\tEnables FPGA subsystem.\n\n\t\tCONFIG_FPGA_\u003cvendor\u003e\n\n\t\tEnables support for specific chip vendors.\n\t\t(ALTERA, XILINX)\n\n\t\tCONFIG_FPGA_\u003cfamily\u003e\n\n\t\tEnables support for FPGA family.\n\t\t(SPARTAN2, SPARTAN3, VIRTEX2, CYCLONE2, ACEX1K, ACEX)\n\n\t\tCONFIG_FPGA_COUNT\n\n\t\tSpecify the number of FPGA devices to support.\n\n\t\tCONFIG_SYS_FPGA_PROG_FEEDBACK\n\n\t\tEnable printing of hash marks during FPGA configuration.\n\n\t\tCONFIG_SYS_FPGA_CHECK_BUSY\n\n\t\tEnable checks on FPGA configuration interface busy\n\t\tstatus by the configuration function. This option\n\t\twill require a board or device specific function to\n\t\tbe written.\n\n\t\tCONFIG_FPGA_DELAY\n\n\t\tIf defined, a function that provides delays in the FPGA\n\t\tconfiguration driver.\n\n\t\tCONFIG_SYS_FPGA_CHECK_CTRLC\n\t\tAllow Control-C to interrupt FPGA configuration\n\n\t\tCONFIG_SYS_FPGA_CHECK_ERROR\n\n\t\tCheck for configuration errors during FPGA bitfile\n\t\tloading. For example, abort during Virtex II\n\t\tconfiguration if the INIT_B line goes low (which\n\t\tindicated a CRC error).\n\n\t\tCONFIG_SYS_FPGA_WAIT_INIT\n\n\t\tMaximum time to wait for the INIT_B line to de-assert\n\t\tafter PROB_B has been de-asserted during a Virtex II\n\t\tFPGA configuration sequence. The default time is 500\n\t\tms.\n\n\t\tCONFIG_SYS_FPGA_WAIT_BUSY\n\n\t\tMaximum time to wait for BUSY to de-assert during\n\t\tVirtex II FPGA configuration. The default is 5 ms.\n\n\t\tCONFIG_SYS_FPGA_WAIT_CONFIG\n\n\t\tTime to wait after FPGA configuration. The default is\n\t\t200 ms.\n\n- Configuration Management:\n\n\t\tCONFIG_IDENT_STRING\n\n\t\tIf defined, this string will be added to the U-Boot\n\t\tversion information (U_BOOT_VERSION)\n\n- Vendor Parameter Protection:\n\n\t\tU-Boot considers the values of the environment\n\t\tvariables \"serial#\" (Board Serial Number) and\n\t\t\"ethaddr\" (Ethernet Address) to be parameters that\n\t\tare set once by the board vendor / manufacturer, and\n\t\tprotects these variables from casual modification by\n\t\tthe user. Once set, these variables are read-only,\n\t\tand write or delete attempts are rejected. You can\n\t\tchange this behaviour:\n\n\t\tIf CONFIG_ENV_OVERWRITE is #defined in your config\n\t\tfile, the write protection for vendor parameters is\n\t\tcompletely disabled. Anybody can change or delete\n\t\tthese parameters.\n\n\t\tAlternatively, if you define _both_ an ethaddr in the\n\t\tdefault env _and_ CONFIG_OVERWRITE_ETHADDR_ONCE, a default\n\t\tEthernet address is installed in the environment,\n\t\twhich can be changed exactly ONCE by the user. [The\n\t\tserial# is unaffected by this, i. e. it remains\n\t\tread-only.]\n\n\t\tThe same can be accomplished in a more flexible way\n\t\tfor any variable by configuring the type of access\n\t\tto allow for those variables in the \".flags\" variable\n\t\tor define CONFIG_ENV_FLAGS_LIST_STATIC.\n\n- Protected RAM:\n\t\tCONFIG_PRAM\n\n\t\tDefine this variable to enable the reservation of\n\t\t\"protected RAM\", i. e. RAM which is not overwritten\n\t\tby U-Boot. Define CONFIG_PRAM to hold the number of\n\t\tkB you want to reserve for pRAM. You can overwrite\n\t\tthis default value by defining an environment\n\t\tvariable \"pram\" to the number of kB you want to\n\t\treserve. Note that the board info structure will\n\t\tstill show the full amount of RAM. If pRAM is\n\t\treserved, a new environment variable \"mem\" will\n\t\tautomatically be defined to hold the amount of\n\t\tremaining RAM in a form that can be passed as boot\n\t\targument to Linux, for instance like that:\n\n\t\t\tsetenv bootargs ... mem=\\${mem}\n\t\t\tsaveenv\n\n\t\tThis way you can tell Linux not to use this memory,\n\t\teither, which results in a memory region that will\n\t\tnot be affected by reboots.\n\n\t\t*WARNING* If your board configuration uses automatic\n\t\tdetection of the RAM size, you must make sure that\n\t\tthis memory test is non-destructive. So far, the\n\t\tfollowing board configurations are known to be\n\t\t\"pRAM-clean\":\n\n\t\t\tIVMS8, IVML24, SPD8xx,\n\t\t\tHERMES, IP860, RPXlite, LWMON,\n\t\t\tFLAGADM\n\n- Access to physical memory region (\u003e 4GB)\n\t\tSome basic support is provided for operations on memory not\n\t\tnormally accessible to U-Boot - e.g. some architectures\n\t\tsupport access to more than 4GB of memory on 32-bit\n\t\tmachines using physical address extension or similar.\n\t\tDefine CONFIG_PHYSMEM to access this basic support, which\n\t\tcurrently only supports clearing the memory.\n\n- Error Recovery:\n\t\tCONFIG_NET_RETRY_COUNT\n\n\t\tThis variable defines the number of retries for\n\t\tnetwork operations like ARP, RARP, TFTP, or BOOTP\n\t\tbefore giving up the operation. If not defined, a\n\t\tdefault value of 5 is used.\n\n\t\tCONFIG_ARP_TIMEOUT\n\n\t\tTimeout waiting for an ARP reply in milliseconds.\n\n\t\tCONFIG_NFS_TIMEOUT\n\n\t\tTimeout in milliseconds used in NFS protocol.\n\t\tIf you encounter \"ERROR: Cannot umount\" in nfs command,\n\t\ttry longer timeout such as\n\t\t#define CONFIG_NFS_TIMEOUT 10000UL\n\n- Command Interpreter:\n\t\tCONFIG_SYS_PROMPT_HUSH_PS2\n\n\t\tThis defines the secondary prompt string, which is\n\t\tprinted when the command interpreter needs more input\n\t\tto complete a command. Usually \"\u003e \".\n\n\tNote:\n\n\t\tIn the current implementation, the local variables\n\t\tspace and global environment variables space are\n\t\tseparated. Local variables are those you define by\n\t\tsimply typing `name=value'. To access a local\n\t\tvariable later on, you have write `$name' or\n\t\t`${name}'; to execute the contents of a variable\n\t\tdirectly type `$name' at the command prompt.\n\n\t\tGlobal environment variables are those you use\n\t\tsetenv/printenv to work with. To run a command stored\n\t\tin such a variable, you need to use the run command,\n\t\tand you must not use the '$' sign to access them.\n\n\t\tTo store commands and special characters in a\n\t\tvariable, please use double quotation marks\n\t\tsurrounding the whole text of the variable, instead\n\t\tof the backslashes before semicolons and special\n\t\tsymbols.\n\n- Command Line Editing and History:\n\t\tCONFIG_CMDLINE_PS_SUPPORT\n\n\t\tEnable support for changing the command prompt string\n\t\tat run-time. Only static string is supported so far.\n\t\tThe string is obtained from environment variables PS1\n\t\tand PS2.\n\n- Default Environment:\n\t\tCONFIG_EXTRA_ENV_SETTINGS\n\n\t\tDefine this to contain any number of null terminated\n\t\tstrings (variable = value pairs) that will be part of\n\t\tthe default environment compiled into the boot image.\n\n\t\tFor example, place something like this in your\n\t\tboard's config file:\n\n\t\t#define CONFIG_EXTRA_ENV_SETTINGS \\\n\t\t\t\"myvar1=value1\\0\" \\\n\t\t\t\"myvar2=value2\\0\"\n\n\t\tWarning: This method is based on knowledge about the\n\t\tinternal format how the environment is stored by the\n\t\tU-Boot code. This is NOT an official, exported\n\t\tinterface! Although it is unlikely that this format\n\t\twill change soon, there is no guarantee either.\n\t\tYou better know what you are doing here.\n\n\t\tNote: overly (ab)use of the default environment is\n\t\tdiscouraged. Make sure to check other ways to preset\n\t\tthe environment like the \"source\" command or the\n\t\tboot command first.\n\n\t\tCONFIG_DELAY_ENVIRONMENT\n\n\t\tNormally the environment is loaded when the board is\n\t\tinitialised so that it is available to U-Boot. This inhibits\n\t\tthat so that the environment is not available until\n\t\texplicitly loaded later by U-Boot code. With CONFIG_OF_CONTROL\n\t\tthis is instead controlled by the value of\n\t\t/config/load-environment.\n\n- TFTP Fixed UDP Port:\n\t\tCONFIG_TFTP_PORT\n\n\t\tIf this is defined, the environment variable tftpsrcp\n\t\tis used to supply the TFTP UDP source port value.\n\t\tIf tftpsrcp isn't defined, the normal pseudo-random port\n\t\tnumber generator is used.\n\n\t\tAlso, the environment variable tftpdstp is used to supply\n\t\tthe TFTP UDP destination port value.  If tftpdstp isn't\n\t\tdefined, the normal port 69 is used.\n\n\t\tThe purpose for tftpsrcp is to allow a TFTP server to\n\t\tblindly start the TFTP transfer using the pre-configured\n\t\ttarget IP address and UDP port. This has the effect of\n\t\t\"punching through\" the (Windows XP) firewall, allowing\n\t\tthe remainder of the TFTP transfer to proceed normally.\n\t\tA better solution is to properly configure the firewall,\n\t\tbut sometimes that is not allowed.\n\n\t\tCONFIG_STANDALONE_LOAD_ADDR\n\n\t\tThis option defines a board specific value for the\n\t\taddress where standalone program gets loaded, thus\n\t\toverwriting the architecture dependent default\n\t\tsettings.\n\n- Frame Buffer Address:\n\t\tCONFIG_FB_ADDR\n\n\t\tDefine CONFIG_FB_ADDR if you want to use specific\n\t\taddress for frame buffer.  This is typically the case\n\t\twhen using a graphics controller has separate video\n\t\tmemory.  U-Boot will then place the frame buffer at\n\t\tthe given address instead of dynamically reserving it\n\t\tin system RAM by calling lcd_setmem(), which grabs\n\t\tthe memory for the frame buffer depending on the\n\t\tconfigured panel size.\n\n\t\tPlease see board_init_f function.\n\n- Automatic software updates via TFTP server\n\t\tCONFIG_UPDATE_TFTP\n\t\tCONFIG_UPDATE_TFTP_CNT_MAX\n\t\tCONFIG_UPDATE_TFTP_MSEC_MAX\n\n\t\tThese options enable and control the auto-update feature;\n\t\tfor a more detailed description refer to doc/README.update.\n\n- MTD Support (mtdparts command, UBI support)\n\t\tCONFIG_MTD_UBI_WL_THRESHOLD\n\t\tThis parameter defines the maximum difference between the highest\n\t\terase counter value and the lowest erase counter value of eraseblocks\n\t\tof UBI devices. When this threshold is exceeded, UBI starts performing\n\t\twear leveling by means of moving data from eraseblock with low erase\n\t\tcounter to eraseblocks with high erase counter.\n\n\t\tThe default value should be OK for SLC NAND flashes, NOR flashes and\n\t\tother flashes which have eraseblock life-cycle 100000 or more.\n\t\tHowever, in case of MLC NAND flashes which typically have eraseblock\n\t\tlife-cycle less than 10000, the threshold should be lessened (e.g.,\n\t\tto 128 or 256, although it does not have to be power of 2).\n\n\t\tdefault: 4096\n\n\t\tCONFIG_MTD_UBI_BEB_LIMIT\n\t\tThis option specifies the maximum bad physical eraseblocks UBI\n\t\texpects on the MTD device (per 1024 eraseblocks). If the\n\t\tunderlying flash does not admit of bad eraseblocks (e.g. NOR\n\t\tflash), this value is ignored.\n\n\t\tNAND datasheets often specify the minimum and maximum NVM\n\t\t(Number of Valid Blocks) for the flashes' endurance lifetime.\n\t\tThe maximum expected bad eraseblocks per 1024 eraseblocks\n\t\tthen can be calculated as \"1024 * (1 - MinNVB / MaxNVB)\",\n\t\twhich gives 20 for most NANDs (MaxNVB is basically the total\n\t\tcount of eraseblocks on the chip).\n\n\t\tTo put it differently, if this value is 20, UBI will try to\n\t\treserve about 1.9% of physical eraseblocks for bad blocks\n\t\thandling. And that will be 1.9% of eraseblocks on the entire\n\t\tNAND chip, not just the MTD partition UBI attaches. This means\n\t\tthat if you have, say, a NAND flash chip admits maximum 40 bad\n\t\teraseblocks, and it is split on two MTD partitions of the same\n\t\tsize, UBI will reserve 40 eraseblocks when attaching a\n\t\tpartition.\n\n\t\tdefault: 20\n\n\t\tCONFIG_MTD_UBI_FASTMAP\n\t\tFastmap is a mechanism which allows attaching an UBI device\n\t\tin nearly constant time. Instead of scanning the whole MTD device it\n\t\tonly has to locate a checkpoint (called fastmap) on the device.\n\t\tThe on-flash fastmap contains all information needed to attach\n\t\tthe device. Using fastmap makes only sense on large devices where\n\t\tattaching by scanning takes long. UBI will not automatically install\n\t\ta fastmap on old images, but you can set the UBI parameter\n\t\tCONFIG_MTD_UBI_FASTMAP_AUTOCONVERT to 1 if you want so. Please note\n\t\tthat fastmap-enabled images are still usable with UBI implementations\n\t\twithout\tfastmap support. On typical flash devices the whole fastmap\n\t\tfits into one PEB. UBI will reserve PEBs to hold two fastmaps.\n\n\t\tCONFIG_MTD_UBI_FASTMAP_AUTOCONVERT\n\t\tSet this parameter to enable fastmap automatically on images\n\t\twithout a fastmap.\n\t\tdefault: 0\n\n\t\tCONFIG_MTD_UBI_FM_DEBUG\n\t\tEnable UBI fastmap debug\n\t\tdefault: 0\n\n- SPL framework\n\t\tCONFIG_SPL\n\t\tEnable building of SPL globally.\n\n\t\tCONFIG_SPL_LDSCRIPT\n\t\tLDSCRIPT for linking the SPL binary.\n\n\t\tCONFIG_SPL_MAX_FOOTPRINT\n\t\tMaximum size in memory allocated to the SPL, BSS included.\n\t\tWhen defined, the linker checks that the actual memory\n\t\tused by SPL from _start to __bss_end does not exceed it.\n\t\tCONFIG_SPL_MAX_FOOTPRINT and CONFIG_SPL_BSS_MAX_SIZE\n\t\tmust not be both defined at the same time.\n\n\t\tCONFIG_SPL_MAX_SIZE\n\t\tMaximum size of the SPL image (text, data, rodata, and\n\t\tlinker lists sections), BSS excluded.\n\t\tWhen defined, the linker checks that the actual size does\n\t\tnot exceed it.\n\n\t\tCONFIG_SPL_RELOC_TEXT_BASE\n\t\tAddress to relocate to.  If unspecified, this is equal to\n\t\tCONFIG_SPL_TEXT_BASE (i.e. no relocation is done).\n\n\t\tCONFIG_SPL_BSS_START_ADDR\n\t\tLink address for the BSS within the SPL binary.\n\n\t\tCONFIG_SPL_BSS_MAX_SIZE\n\t\tMaximum size in memory allocated to the SPL BSS.\n\t\tWhen defined, the linker checks that the actual memory used\n\t\tby SPL from __bss_start to __bss_end does not exceed it.\n\t\tCONFIG_SPL_MAX_FOOTPRINT and CONFIG_SPL_BSS_MAX_SIZE\n\t\tmust not be both defined at the same time.\n\n\t\tCONFIG_SPL_STACK\n\t\tAdress of the start of the stack SPL will use\n\n\t\tCONFIG_SPL_PANIC_ON_RAW_IMAGE\n\t\tWhen defined, SPL will panic() if the image it has\n\t\tloaded does not have a signature.\n\t\tDefining this is useful when code which loads images\n\t\tin SPL cannot guarantee that absolutely all read errors\n\t\twill be caught.\n\t\tAn example is the LPC32XX MLC NAND driver, which will\n\t\tconsider that a completely unreadable NAND block is bad,\n\t\tand thus should be skipped silently.\n\n\t\tCONFIG_SPL_RELOC_STACK\n\t\tAdress of the start of the stack SPL will use after\n\t\trelocation.  If unspecified, this is equal to\n\t\tCONFIG_SPL_STACK.\n\n\t\tCONFIG_SYS_SPL_MALLOC_START\n\t\tStarting address of the malloc pool used in SPL.\n\t\tWhen this option is set the full malloc is used in SPL and\n\t\tit is set up by spl_init() and before that, the simple malloc()\n\t\tcan be used if CONFIG_SYS_MALLOC_F is defined.\n\n\t\tCONFIG_SYS_SPL_MALLOC_SIZE\n\t\tThe size of the malloc pool used in SPL.\n\n\t\tCONFIG_SPL_OS_BOOT\n\t\tEnable booting directly to an OS from SPL.\n\t\tSee also: doc/README.falcon\n\n\t\tCONFIG_SPL_DISPLAY_PRINT\n\t\tFor ARM, enable an optional function to print more information\n\t\tabout the running system.\n\n\t\tCONFIG_SPL_INIT_MINIMAL\n\t\tArch init code should be built for a very small image\n\n\t\tCONFIG_SYS_MMCSD_RAW_MODE_U_BOOT_PARTITION\n\t\tPartition on the MMC to load U-Boot from when the MMC is being\n\t\tused in raw mode\n\n\t\tCONFIG_SYS_MMCSD_RAW_MODE_KERNEL_SECTOR\n\t\tSector to load kernel uImage from when MMC is being\n\t\tused in raw mode (for Falcon mode)\n\n\t\tCONFIG_SYS_MMCSD_RAW_MODE_ARGS_SECTOR,\n\t\tCONFIG_SYS_MMCSD_RAW_MODE_ARGS_SECTORS\n\t\tSector and number of sectors to load kernel argument\n\t\tparameters from when MMC is being used in raw mode\n\t\t(for falcon mode)\n\n\t\tCONFIG_SPL_FS_LOAD_PAYLOAD_NAME\n\t\tFilename to read to load U-Boot when reading from filesystem\n\n\t\tCONFIG_SPL_FS_LOAD_KERNEL_NAME\n\t\tFilename to read to load kernel uImage when reading\n\t\tfrom filesystem (for Falcon mode)\n\n\t\tCONFIG_SPL_FS_LOAD_ARGS_NAME\n\t\tFilename to read to load kernel argument parameters\n\t\twhen reading from filesystem (for Falcon mode)\n\n\t\tCONFIG_SPL_MPC83XX_WAIT_FOR_NAND\n\t\tSet this for NAND SPL on PPC mpc83xx targets, so that\n\t\tstart.S waits for the rest of the SPL to load before\n\t\tcontinuing (the hardware starts execution after just\n\t\tloading the first page rather than the full 4K).\n\n\t\tCONFIG_SPL_SKIP_RELOCATE\n\t\tAvoid SPL relocation\n\n\t\tCONFIG_SPL_NAND_IDENT\n\t\tSPL uses the chip ID list to identify the NAND flash.\n\t\tRequires CONFIG_SPL_NAND_BASE.\n\n\t\tCONFIG_SPL_UBI\n\t\tSupport for a lightweight UBI (fastmap) scanner and\n\t\tloader\n\n\t\tCONFIG_SPL_NAND_RAW_ONLY\n\t\tSupport to boot only raw u-boot.bin images. Use this only\n\t\tif you need to save space.\n\n\t\tCONFIG_SPL_COMMON_INIT_DDR\n\t\tSet for common ddr init with serial presence detect in\n\t\tSPL binary.\n\n\t\tCONFIG_SYS_NAND_5_ADDR_CYCLE, CONFIG_SYS_NAND_PAGE_COUNT,\n\t\tCONFIG_SYS_NAND_PAGE_SIZE, CONFIG_SYS_NAND_OOBSIZE,\n\t\tCONFIG_SYS_NAND_BLOCK_SIZE, CONFIG_SYS_NAND_BAD_BLOCK_POS,\n\t\tCONFIG_SYS_NAND_ECCPOS, CONFIG_SYS_NAND_ECCSIZE,\n\t\tCONFIG_SYS_NAND_ECCBYTES\n\t\tDefines the size and behavior of the NAND that SPL uses\n\t\tto read U-Boot\n\n\t\tCONFIG_SYS_NAND_U_BOOT_OFFS\n\t\tLocation in NAND to read U-Boot from\n\n\t\tCONFIG_SYS_NAND_U_BOOT_DST\n\t\tLocation in memory to load U-Boot to\n\n\t\tCONFIG_SYS_NAND_U_BOOT_SIZE\n\t\tSize of image to load\n\n\t\tCONFIG_SYS_NAND_U_BOOT_START\n\t\tEntry point in loaded image to jump to\n\n\t\tCONFIG_SYS_NAND_HW_ECC_OOBFIRST\n\t\tDefine this if you need to first read the OOB and then the\n\t\tdata. This is used, for example, on davinci platforms.\n\n\t\tCONFIG_SPL_RAM_DEVICE\n\t\tSupport for running image already present in ram, in SPL binary\n\n\t\tCONFIG_SPL_PAD_TO\n\t\tImage offset to which the SPL should be padded before appending\n\t\tthe SPL payload. By default, this is defined as\n\t\tCONFIG_SPL_MAX_SIZE, or 0 if CONFIG_SPL_MAX_SIZE is undefined.\n\t\tCONFIG_SPL_PAD_TO must be either 0, meaning to append the SPL\n\t\tpayload without any padding, or \u003e= CONFIG_SPL_MAX_SIZE.\n\n\t\tCONFIG_SPL_TARGET\n\t\tFinal target image containing SPL and payload.  Some SPLs\n\t\tuse an arch-specific makefile fragment instead, for\n\t\texample if more than one image needs to be produced.\n\n\t\tCONFIG_SPL_FIT_PRINT\n\t\tPrinting information about a FIT image adds quite a bit of\n\t\tcode to SPL. So this is normally disabled in SPL. Use this\n\t\toption to re-enable it. This will affect the output of the\n\t\tbootm command when booting a FIT image.\n\n- TPL framework\n\t\tCONFIG_TPL\n\t\tEnable building of TPL globally.\n\n\t\tCONFIG_TPL_PAD_TO\n\t\tImage offset to which the TPL should be padded before appending\n\t\tthe TPL payload. By default, this is defined as\n\t\tCONFIG_SPL_MAX_SIZE, or 0 if CONFIG_SPL_MAX_SIZE is undefined.\n\t\tCONFIG_SPL_PAD_TO must be either 0, meaning to append the SPL\n\t\tpayload without any padding, or \u003e= CONFIG_SPL_MAX_SIZE.\n\n- Interrupt support (PPC):\n\n\t\tThere are common interrupt_init() and timer_interrupt()\n\t\tfor all PPC archs. interrupt_init() calls interrupt_init_cpu()\n\t\tfor CPU specific initialization. interrupt_init_cpu()\n\t\tshould set decrementer_count to appropriate value. If\n\t\tCPU resets decrementer automatically after interrupt\n\t\t(ppc4xx) it should set decrementer_count to zero.\n\t\ttimer_interrupt() calls timer_interrupt_cpu() for CPU\n\t\tspecific handling. If board has watchdog / status_led\n\t\t/ other_activity_monitor it works automatically from\n\t\tgeneral timer_interrupt().\n\n\nBoard initialization settings:\n------------------------------\n\nDuring Initialization u-boot calls a number of board specific functions\nto allow the preparation of board specific prerequisites, e.g. pin setup\nbefore drivers are initialized. To enable these callbacks the\nfollowing configuration macros have to be defined. Currently this is\narchitecture specific, so please check arch/your_architecture/lib/board.c\ntypically in board_init_f() and board_init_r().\n\n- CONFIG_BOARD_EARLY_INIT_F: Call board_early_init_f()\n- CONFIG_BOARD_EARLY_INIT_R: Call board_early_init_r()\n- CONFIG_BOARD_LATE_INIT: Call board_late_init()\n- CONFIG_BOARD_POSTCLK_INIT: Call board_postclk_init()\n\nConfiguration Settings:\n-----------------------\n\n- MEM_SUPPORT_64BIT_DATA: Defined automatically if compiled as 64-bit.\n\t\tOptionally it can be defined to support 64-bit memory commands.\n\n- CONFIG_SYS_LONGHELP: Defined when you want long help messages included;\n\t\tundefine this when you're short of memory.\n\n- CONFIG_SYS_HELP_CMD_WIDTH: Defined when you want to override the default\n\t\twidth of the commands listed in the 'help' command output.\n\n- CONFIG_SYS_PROMPT:\tThis is what U-Boot prints on the console to\n\t\tprompt for user input.\n\n- CONFIG_SYS_CBSIZE:\tBuffer size for input from the Console\n\n- CONFIG_SYS_PBSIZE:\tBuffer size for Console output\n\n- CONFIG_SYS_MAXARGS:\tmax. Number of arguments accepted for monitor commands\n\n- CONFIG_SYS_BARGSIZE: Buffer size for Boot Arguments which are passed to\n\t\tthe application (usually a Linux kernel) when it is\n\t\tbooted\n\n- CONFIG_SYS_BAUDRATE_TABLE:\n\t\tList of legal baudrate settings for this board.\n\n- CONFIG_SYS_MEM_RESERVE_SECURE\n\t\tOnly implemented for ARMv8 for now.\n\t\tIf defined, the size of CONFIG_SYS_MEM_RESERVE_SECURE memory\n\t\tis substracted from total RAM and won't be reported to OS.\n\t\tThis memory can be used as secure memory. A variable\n\t\tgd-\u003earch.secure_ram is used to track the location. In systems\n\t\tthe RAM base is not zero, or RAM is divided into banks,\n\t\tthis variable needs to be recalcuated to get the address.\n\n- CONFIG_SYS_MEM_TOP_HIDE:\n\t\tIf CONFIG_SYS_MEM_TOP_HIDE is defined in the board config header,\n\t\tthis specified memory area will get subtracted from the top\n\t\t(end) of RAM and won't get \"touched\" at all by U-Boot. By\n\t\tfixing up gd-\u003eram_size the Linux kernel should gets passed\n\t\tthe now \"corrected\" memory size and won't touch it either.\n\t\tThis should work for arch/ppc and arch/powerpc. Only Linux\n\t\tboard ports in arch/powerpc with bootwrapper support that\n\t\trecalculate the memory size from the SDRAM controller setup\n\t\twill have to get fixed in Linux additionally.\n\n\t\tThis option can be used as a workaround for the 440EPx/GRx\n\t\tCHIP 11 errata where the last 256 bytes in SDRAM shouldn't\n\t\tbe touched.\n\n\t\tWARNING: Please make sure that this value is a multiple of\n\t\tthe Linux page size (normally 4k). If this is not the case,\n\t\tthen the end address of the Linux memory will be located at a\n\t\tnon page size aligned address and this could cause major\n\t\tproblems.\n\n- CONFIG_SYS_LOADS_BAUD_CHANGE:\n\t\tEnable temporary baudrate change while serial download\n\n- CONFIG_SYS_SDRAM_BASE:\n\t\tPhysical start address of SDRAM. _Must_ be 0 here.\n\n- CONFIG_SYS_FLASH_BASE:\n\t\tPhysical start address of Flash memory.\n\n- CONFIG_SYS_MONITOR_BASE:\n\t\tPhysical start address of boot monitor code (set by\n\t\tmake config files to be same as the text base address\n\t\t(CONFIG_SYS_TEXT_BASE) used when linking) - same as\n\t\tCONFIG_SYS_FLASH_BASE when booting from flash.\n\n- CONFIG_SYS_MONITOR_LEN:\n\t\tSize of memory reserved for monitor code, used to\n\t\tdetermine _at_compile_time_ (!) if the environment is\n\t\tembedded within the U-Boot image, or in a separate\n\t\tflash sector.\n\n- CONFIG_SYS_MALLOC_LEN:\n\t\tSize of DRAM reserved for malloc() use.\n\n- CONFIG_SYS_MALLOC_F_LEN\n\t\tSize of the malloc() pool for use before relocation. If\n\t\tthis is defined, then a very simple malloc() implementation\n\t\twill become available before relocation. The address is just\n\t\tbelow the global data, and the stack is moved down to make\n\t\tspace.\n\n\t\tThis feature allocates regions with increasing addresses\n\t\twithin the region. calloc() is supported, but realloc()\n\t\tis not available. free() is supported but does nothing.\n\t\tThe memory will be freed (or in fact just forgotten) when\n\t\tU-Boot relocates itself.\n\n- CONFIG_SYS_MALLOC_SIMPLE\n\t\tProvides a simple and small malloc() and calloc() for those\n\t\tboards which do not use the full malloc in SPL (which is\n\t\tenabled with CONFIG_SYS_SPL_MALLOC_START).\n\n- CONFIG_SYS_NONCACHED_MEMORY:\n\t\tSize of non-cached memory area. This area of memory will be\n\t\ttypically located right below the malloc() area and mapped\n\t\tuncached in the MMU. This is useful for drivers that would\n\t\totherwise require a lot of explicit cache maintenance. For\n\t\tsome drivers it's also impossible to properly maintain the\n\t\tcache. For example if the regions that need to be flushed\n\t\tare not a multiple of the cache-line size, *and* padding\n\t\tcannot be allocated between the regions to align them (i.e.\n\t\tif the HW requires a contiguous array of regions, and the\n\t\tsize of each region is not cache-aligned), then a flush of\n\t\tone region may result in overwriting data that hardware has\n\t\twritten to another region in the same cache-line. This can\n\t\thappen for example in network drivers where descriptors for\n\t\tbuffers are typically smaller than the CPU cache-line (e.g.\n\t\t16 bytes vs. 32 or 64 bytes).\n\n\t\tNon-cached memory is only supported on 32-bit ARM at present.\n\n- CONFIG_SYS_BOOTM_LEN:\n\t\tNormally compressed uImages are limited to an\n\t\tuncompressed size of 8 MBytes. If this is not enough,\n\t\tyou can define CONFIG_SYS_BOOTM_LEN in your board config file\n\t\tto adjust this setting to your needs.\n\n- CONFIG_SYS_BOOTMAPSZ:\n\t\tMaximum size of memory mapped by the startup code of\n\t\tthe Linux kernel; all data that must be processed by\n\t\tthe Linux kernel (bd_info, boot arguments, FDT blob if\n\t\tused) must be put below this limit, unless \"bootm_low\"\n\t\tenvironment variable is defined and non-zero. In such case\n\t\tall data for the Linux kernel must be between \"bootm_low\"\n\t\tand \"bootm_low\" + CONFIG_SYS_BOOTMAPSZ.\t The environment\n\t\tvariable \"bootm_mapsize\" will override the value of\n\t\tCONFIG_SYS_BOOTMAPSZ.  If CONFIG_SYS_BOOTMAPSZ is undefined,\n\t\tthen the value in \"bootm_size\" will be used instead.\n\n- CONFIG_SYS_BOOT_RAMDISK_HIGH:\n\t\tEnable initrd_high functionality.  If defined then the\n\t\tinitrd_high feature is enabled and the bootm ramdisk subcommand\n\t\tis enabled.\n\n- CONFIG_SYS_BOOT_GET_CMDLINE:\n\t\tEnables allocating and saving kernel cmdline in space between\n\t\t\"bootm_low\" and \"bootm_low\" + BOOTMAPSZ.\n\n- CONFIG_SYS_BOOT_GET_KBD:\n\t\tEnables allocating and saving a kernel copy of the bd_info in\n\t\tspace between \"bootm_low\" and \"bootm_low\" + BOOTMAPSZ.\n\n- CONFIG_SYS_MAX_FLASH_BANKS:\n\t\tMax number of Flash memory banks\n\n- CONFIG_SYS_MAX_FLASH_SECT:\n\t\tMax number of sectors on a Flash chip\n\n- CONFIG_SYS_FLASH_ERASE_TOUT:\n\t\tTimeout for Flash erase operations (in ms)\n\n- CONFIG_SYS_FLASH_WRITE_TOUT:\n\t\tTimeout for Flash write operations (in ms)\n\n- CONFIG_SYS_FLASH_LOCK_TOUT\n\t\tTimeout for Flash set sector lock bit operation (in ms)\n\n- CONFIG_SYS_FLASH_UNLOCK_TOUT\n\t\tTimeout for Flash clear lock bits operation (in ms)\n\n- CONFIG_SYS_FLASH_PROTECTION\n\t\tIf defined, hardware flash sectors protection is used\n\t\tinstead of U-Boot software protection.\n\n- CONFIG_SYS_DIRECT_FLASH_TFTP:\n\n\t\tEnable TFTP transfers directly to flash memory;\n\t\twithout this option such a download has to be\n\t\tperformed in two steps: (1) download to RAM, and (2)\n\t\tcopy from RAM to flash.\n\n\t\tThe two-step approach is usually more reliable, since\n\t\tyou can check if the download worked before you erase\n\t\tthe flash, but in some situations (when system RAM is\n\t\ttoo limited to allow for a temporary copy of the\n\t\tdownloaded image) this option may be very useful.\n\n- CONFIG_SYS_FLASH_CFI:\n\t\tDefine if the flash driver uses extra elements in the\n\t\tcommon flash structure for storing flash geometry.\n\n- CONFIG_FLASH_CFI_DRIVER\n\t\tThis option also enables the building of the cfi_flash driver\n\t\tin the drivers directory\n\n- CONFIG_FLASH_CFI_MTD\n\t\tThis option enables the building of the cfi_mtd driver\n\t\tin the drivers directory. The driver exports CFI flash\n\t\tto the MTD layer.\n\n- CONFIG_SYS_FLASH_USE_BUFFER_WRITE\n\t\tUse buffered writes to flash.\n\n- CONFIG_FLASH_SPANSION_S29WS_N\n\t\ts29ws-n MirrorBit flash has non-standard addresses for buffered\n\t\twrite commands.\n\n- CONFIG_SYS_FLASH_QUIET_TEST\n\t\tIf this option is defined, the common CFI flash doesn't\n\t\tprint it's warning upon not recognized FLASH banks. This\n\t\tis useful, if some of the configured banks are only\n\t\toptionally available.\n\n- CONFIG_FLASH_SHOW_PROGRESS\n\t\tIf defined (must be an integer), print out countdown\n\t\tdigits and dots.  Recommended value: 45 (9..1) for 80\n\t\tcolumn displays, 15 (3..1) for 40 column displays.\n\n- CONFIG_FLASH_VERIFY\n\t\tIf defined, the content of the flash (destination) is compared\n\t\tagainst the source after the write operation. An error message\n\t\twill be printed when the contents are not identical.\n\t\tPlease note that this option is useless in nearly all cases,\n\t\tsince such flash programming errors usually are detected earlier\n\t\twhile unprotecting/erasing/programming. Please only enable\n\t\tthis option if you really know what you are doing.\n\n- CONFIG_SYS_RX_ETH_BUFFER:\n\t\tDefines the number of Ethernet receive buffers. On some\n\t\tEthernet controllers it is recommended to set this value\n\t\tto 8 or even higher (EEPRO100 or 405 EMAC), since all\n\t\tbuffers can be full shortly after enabling the interface\n\t\ton high Ethernet traffic.\n\t\tDefaults to 4 if not defined.\n\n- CONFIG_ENV_MAX_ENTRIES\n\n\tMaximum number of entries in the hash table that is used\n\tinternally to store the environment settings. The default\n\tsetting is supposed to be generous and should work in most\n\tcases. This setting can be used to tune behaviour; see\n\tlib/hashtable.c for details.\n\n- CONFIG_ENV_FLAGS_LIST_DEFAULT\n- CONFIG_ENV_FLAGS_LIST_STATIC\n\tEnable validation of the values given to environment variables when\n\tcalling env set.  Variables can be restricted to only decimal,\n\thexadecimal, or boolean.  If CONFIG_CMD_NET is also defined,\n\tthe variables can also be restricted to IP address or MAC address.\n\n\tThe format of the list is:\n\t\ttype_attribute = [s|d|x|b|i|m]\n\t\taccess_attribute = [a|r|o|c]\n\t\tattributes = type_attribute[access_attribute]\n\t\tentry = variable_name[:attributes]\n\t\tlist = entry[,list]\n\n\tThe type attributes are:\n\t\ts - String (default)\n\t\td - Decimal\n\t\tx - Hexadecimal\n\t\tb - Boolean ([1yYtT|0nNfF])\n\t\ti - IP address\n\t\tm - MAC address\n\n\tThe access attributes are:\n\t\ta - Any (default)\n\t\tr - Read-only\n\t\to - Write-once\n\t\tc - Change-default\n\n\t- CONFIG_ENV_FLAGS_LIST_DEFAULT\n\t\tDefine this to a list (string) to define the \".flags\"\n\t\tenvironment variable in the default or embedded environment.\n\n\t- CONFIG_ENV_FLAGS_LIST_STATIC\n\t\tDefine this to a list (string) to define validation that\n\t\tshould be done if an entry is not found in the \".flags\"\n\t\tenvironment variable.  To override a setting in the static\n\t\tlist, simply add an entry for the same variable name to the\n\t\t\".flags\" variable.\n\n\tIf CONFIG_REGEX is defined, the variable_name above is evaluated as a\n\tregular expression. This allows multiple variables to define the same\n\tflags without explicitly listing them for each variable.\n\nThe following definitions that deal with the placement and management\nof environment data (variable area); in general, we support the\nfollowing configurations:\n\n- CONFIG_BUILD_ENVCRC:\n\n\tBuilds up envcrc with the target environment so that external utils\n\tmay easily extract it and embed it in final U-Boot images.\n\nBE CAREFUL! The first access to the environment happens quite early\nin U-Boot initialization (when we try to get the setting of for the\nconsole baudrate). You *MUST* have mapped your NVRAM area then, or\nU-Boot will hang.\n\nPlease note that even with NVRAM we still use a copy of the\nenvironment in RAM: we could work on NVRAM directly, but we want to\nkeep settings there always unmodified except somebody uses \"saveenv\"\nto save the current settings.\n\nBE CAREFUL! For some special cases, the local device can not use\n\"saveenv\" command. For example, the local device will get the\nenvironment stored in a remote NOR flash by SRIO or PCIE link,\nbut it can not erase, write this NOR flash by SRIO or PCIE interface.\n\n- CONFIG_NAND_ENV_DST\n\n\tDefines address in RAM to which the nand_spl code should copy the\n\tenvironment. If redundant environment is used, it will be copied to\n\tCONFIG_NAND_ENV_DST + CONFIG_ENV_SIZE.\n\nPlease note that the environment is read-only until the monitor\nhas been relocated to RAM and a RAM copy of the environment has been\ncreated; also, when using EEPROM you will have to use env_get_f()\nuntil then to read environment variables.\n\nThe environment is protected by a CRC32 checksum. Before the monitor\nis relocated into RAM, as a result of a bad CRC you will be working\nwith the compiled-in default environment - *silently*!!! [This is\nnecessary, because the first environment variable we need is the\n\"baudrate\" setting for the console - if we have a bad CRC, we don't\nhave any device yet where we could complain.]\n\nNote: once the monitor has been relocated, then it will complain if\nthe default environment is used; a new CRC is computed as soon as you\nuse the \"saveenv\" command to store a valid environment.\n\n- CONFIG_SYS_FAULT_ECHO_LINK_DOWN:\n\t\tEcho the inverted Ethernet link state to the fault LED.\n\n\t\tNote: If this option is active, then CONFIG_SYS_FAULT_MII_ADDR\n\t\t      also needs to be defined.\n\n- CONFIG_SYS_FAULT_MII_ADDR:\n\t\tMII address of the PHY to check for the Ethernet link state.\n\n- CONFIG_NS16550_MIN_FUNCTIONS:\n\t\tDefine this if you desire to only have use of the NS16550_init\n\t\tand NS16550_putc functions for the serial driver located at\n\t\tdrivers/serial/ns16550.c.  This option is useful for saving\n\t\tspace for already greatly restricted images, including but not\n\t\tlimited to NAND_SPL configurations.\n\n- CONFIG_DISPLAY_BOARDINFO\n\t\tDisplay information about the board that U-Boot is running on\n\t\twhen U-Boot starts up. The board function checkboard() is called\n\t\tto do this.\n\n- CONFIG_DISPLAY_BOARDINFO_LATE\n\t\tSimilar to the previous option, but display this information\n\t\tlater, once stdio is running and output goes to the LCD, if\n\t\tpresent.\n\n- CONFIG_BOARD_SIZE_LIMIT:\n\t\tMaximum size of the U-Boot image. When defined, the\n\t\tbuild system checks that the actual size does not\n\t\texceed it.\n\nLow Level (hardware related) configuration options:\n---------------------------------------------------\n\n- CONFIG_SYS_CACHELINE_SIZE:\n\t\tCache Line Size of the CPU.\n\n- CONFIG_SYS_CCSRBAR_DEFAULT:\n\t\tDefault (power-on reset) physical address of CCSR on Freescale\n\t\tPowerPC SOCs.\n\n- CONFIG_SYS_CCSRBAR:\n\t\tVirtual address of CCSR.  On a 32-bit build, this is typically\n\t\tthe same value as CONFIG_SYS_CCSRBAR_DEFAULT.\n\n- CONFIG_SYS_CCSRBAR_PHYS:\n\t\tPhysical address of CCSR.  CCSR can be relocated to a new\n\t\tphysical address, if desired.  In this case, this macro should\n\t\tbe set to that address.\t Otherwise, it should be set to the\n\t\tsame value as CONFIG_SYS_CCSRBAR_DEFAULT.  For example, CCSR\n\t\tis typically relocated on 36-bit builds.  It is recommended\n\t\tthat this macro be defined via the _HIGH and _LOW macros:\n\n\t\t#define CONFIG_SYS_CCSRBAR_PHYS ((CONFIG_SYS_CCSRBAR_PHYS_HIGH\n\t\t\t* 1ull) \u003c\u003c 32 | CONFIG_SYS_CCSRBAR_PHYS_LOW)\n\n- CONFIG_SYS_CCSRBAR_PHYS_HIGH:\n\t\tBits 33-36 of CONFIG_SYS_CCSRBAR_PHYS.\tThis value is typically\n\t\teither 0 (32-bit build) or 0xF (36-bit build).\tThis macro is\n\t\tused in assembly code, so it must not contain typecasts or\n\t\tinteger size suffixes (e.g. \"ULL\").\n\n- CONFIG_SYS_CCSRBAR_PHYS_LOW:\n\t\tLower 32-bits of CONFIG_SYS_CCSRBAR_PHYS.  This macro is\n\t\tused in assembly code, so it must not contain typecasts or\n\t\tinteger size suffixes (e.g. \"ULL\").\n\n- CONFIG_SYS_CCSR_DO_NOT_RELOCATE:\n\t\tIf this macro is defined, then CONFIG_SYS_CCSRBAR_PHYS will be\n\t\tforced to a value that ensures that CCSR is not relocated.\n\n- CONFIG_IDE_AHB:\n\t\tMost IDE controllers were designed to be connected with PCI\n\t\tinterface. Only few of them were designed for AHB interface.\n\t\tWhen software is doing ATA command and data transfer to\n\t\tIDE devices through IDE-AHB controller, some additional\n\t\tregisters accessing to these kind of IDE-AHB controller\n\t\tis required.\n\n- CONFIG_SYS_IMMR:\tPhysical address of the Internal Memory.\n\t\tDO NOT CHANGE unless you know exactly what you're\n\t\tdoing! (11-4) [MPC8xx systems only]\n\n- CONFIG_SYS_INIT_RAM_ADDR:\n\n\t\tStart address of memory area that can be used for\n\t\tinitial data and stack; please note that this must be\n\t\twritable memory that is working WITHOUT special\n\t\tinitialization, i. e. you CANNOT use normal RAM which\n\t\twill become available only after programming the\n\t\tmemory controller and running certain initialization\n\t\tsequences.\n\n\t\tU-Boot uses the following memory types:\n\t\t- MPC8xx: IMMR (internal memory of the CPU)\n\n- CONFIG_SYS_GBL_DATA_OFFSET:\n\n\t\tOffset of the initial data structure in the memory\n\t\tarea defined by CONFIG_SYS_INIT_RAM_ADDR. Usually\n\t\tCONFIG_SYS_GBL_DATA_OFFSET is chosen such that the initial\n\t\tdata is located at the end of the available space\n\t\t(sometimes written as (CONFIG_SYS_INIT_RAM_SIZE -\n\t\tGENERATED_GBL_DATA_SIZE), and the initial stack is just\n\t\tbelow that area (growing from (CONFIG_SYS_INIT_RAM_ADDR +\n\t\tCONFIG_SYS_GBL_DATA_OFFSET) downward.\n\n\tNote:\n\t\tOn the MPC824X (or other systems that use the data\n\t\tcache for initial memory) the address chosen for\n\t\tCONFIG_SYS_INIT_RAM_ADDR is basically arbitrary - it must\n\t\tpoint to an otherwise UNUSED address space between\n\t\tthe top of RAM and the start of the PCI space.\n\n- CONFIG_SYS_SCCR:\tSystem Clock and reset Control Register (15-27)\n\n- CONFIG_SYS_OR_TIMING_SDRAM:\n\t\tSDRAM timing\n\n- CONFIG_SYS_MAMR_PTA:\n\t\tperiodic timer for refresh\n\n- FLASH_BASE0_PRELIM, FLASH_BASE1_PRELIM, CONFIG_SYS_REMAP_OR_AM,\n  CONFIG_SYS_PRELIM_OR_AM, CONFIG_SYS_OR_TIMING_FLASH, CONFIG_SYS_OR0_REMAP,\n  CONFIG_SYS_OR0_PRELIM, CONFIG_SYS_BR0_PRELIM, CONFIG_SYS_OR1_REMAP, CONFIG_SYS_OR1_PRELIM,\n  CONFIG_SYS_BR1_PRELIM:\n\t\tMemory Controller Definitions: BR0/1 and OR0/1 (FLASH)\n\n- SDRAM_BASE2_PRELIM, SDRAM_BASE3_PRELIM, SDRAM_MAX_SIZE,\n  CONFIG_SYS_OR_TIMING_SDRAM, CONFIG_SYS_OR2_PRELIM, CONFIG_SYS_BR2_PRELIM,\n  CONFIG_SYS_OR3_PRELIM, CONFIG_SYS_BR3_PRELIM:\n\t\tMemory Controller Definitions: BR2/3 and OR2/3 (SDRAM)\n\n- CONFIG_PCI_ENUM_ONLY\n\t\tOnly scan through and get the devices on the buses.\n\t\tDon't do any setup work, presumably because someone or\n\t\tsomething has already done it, and we don't need to do it\n\t\ta second time.\tUseful for platforms that are pre-booted\n\t\tby coreboot or similar.\n\n- CONFIG_PCI_INDIRECT_BRIDGE:\n\t\tEnable support for indirect PCI bridges.\n\n- CONFIG_SYS_SRIO:\n\t\tChip has SRIO or not\n\n- CONFIG_SRIO1:\n\t\tBoard has SRIO 1 port available\n\n- CONFIG_SRIO2:\n\t\tBoard has SRIO 2 port available\n\n- CONFIG_SRIO_PCIE_BOOT_MASTER\n\t\tBoard can support master function for Boot from SRIO and PCIE\n\n- CONFIG_SYS_SRIOn_MEM_VIRT:\n\t\tVirtual Address of SRIO port 'n' memory region\n\n- CONFIG_SYS_SRIOn_MEM_PHYxS:\n\t\tPhysical Address of SRIO port 'n' memory region\n\n- CONFIG_SYS_SRIOn_MEM_SIZE:\n\t\tSize of SRIO port 'n' memory region\n\n- CONFIG_SYS_NAND_BUSWIDTH_16BIT\n\t\tDefined to tell the NAND controller that the NAND chip is using\n\t\ta 16 bit bus.\n\t\tNot all NAND drivers use this symbol.\n\t\tExample of drivers that use it:\n\t\t- drivers/mtd/nand/raw/ndfc.c\n\t\t- drivers/mtd/nand/raw/mxc_nand.c\n\n- CONFIG_SYS_NDFC_EBC0_CFG\n\t\tSets the EBC0_CFG register for the NDFC. If not defined\n\t\ta default value will be used.\n\n- CONFIG_SPD_EEPROM\n\t\tGet DDR timing information from an I2C EEPROM. Common\n\t\twith pluggable memory modules such as SODIMMs\n\n  SPD_EEPROM_ADDRESS\n\t\tI2C address of the SPD EEPROM\n\n- CONFIG_SYS_SPD_BUS_NUM\n\t\tIf SPD EEPROM is on an I2C bus other than the first\n\t\tone, specify here. Note that the value must resolve\n\t\tto something your driver can deal with.\n\n- CONFIG_SYS_DDR_RAW_TIMING\n\t\tGet DDR timing information from other than SPD. Common with\n\t\tsoldered DDR chips onboard without SPD. DDR raw timing\n\t\tparameters are extracted from datasheet and hard-coded into\n\t\theader files or board specific files.\n\n- CONFIG_FSL_DDR_INTERACTIVE\n\t\tEnable interactive DDR debugging. See doc/README.fsl-ddr.\n\n- CONFIG_FSL_DDR_SYNC_REFRESH\n\t\tEnable sync of refresh for multiple controllers.\n\n- CONFIG_FSL_DDR_BIST\n\t\tEnable built-in memory test for Freescale DDR controllers.\n\n- CONFIG_SYS_83XX_DDR_USES_CS0\n\t\tOnly for 83xx systems. If specified, then DDR should\n\t\tbe configured using CS0 and CS1 instead of CS2 and CS3.\n\n- CONFIG_RMII\n\t\tEnable RMII mode for all FECs.\n\t\tNote that this is a global option, we can't\n\t\thave one FEC in standard MII mode and another in RMII mode.\n\n- CONFIG_CRC32_VERIFY\n\t\tAdd a verify option to the crc32 command.\n\t\tThe syntax is:\n\n\t\t=\u003e crc32 -v \u003caddress\u003e \u003ccount\u003e \u003ccrc32\u003e\n\n\t\tWhere address/count indicate a memory area\n\t\tand crc32 is the correct crc32 which the\n\t\tarea should have.\n\n- CONFIG_LOOPW\n\t\tAdd the \"loopw\" memory command. This only takes effect if\n\t\tthe memory commands are activated globally (CONFIG_CMD_MEMORY).\n\n- CONFIG_CMD_MX_CYCLIC\n\t\tAdd the \"mdc\" and \"mwc\" memory commands. These are cyclic\n\t\t\"md/mw\" commands.\n\t\tExamples:\n\n\t\t=\u003e mdc.b 10 4 500\n\t\tThis command will print 4 bytes (10,11,12,13) each 500 ms.\n\n\t\t=\u003e mwc.l 100 12345678 10\n\t\tThis command will write 12345678 to address 100 all 10 ms.\n\n\t\tThis only takes effect if the memory commands are activated\n\t\tglobally (CONFIG_CMD_MEMORY).\n\n- CONFIG_SKIP_LOWLEVEL_INIT\n\t\t[ARM, NDS32, MIPS, RISC-V only] If this variable is defined, then certain\n\t\tlow level initializations (like setting up the memory\n\t\tcontroller) are omitted and/or U-Boot does not\n\t\trelocate itself into RAM.\n\n\t\tNormally this variable MUST NOT be defined. The only\n\t\texception is when U-Boot is loaded (to RAM) by some\n\t\tother boot loader or by a debugger which performs\n\t\tthese initializations itself.\n\n- CONFIG_SKIP_LOWLEVEL_INIT_ONLY\n\t\t[ARM926EJ-S only] This allows just the call to lowlevel_init()\n\t\tto be skipped. The normal CP15 init (such as enabling the\n\t\tinstruction cache) is still performed.\n\n- CONFIG_SPL_BUILD\n\t\tSet when the currently-running compilation is for an artifact\n\t\tthat will end up in the SPL (as opposed to the TPL or U-Boot\n\t\tproper). Code that needs stage-specific behavior should check\n\t\tthis.\n\n- CONFIG_TPL_BUILD\n\t\tSet when the currently-running compilation is for an artifact\n\t\tthat will end up in the TPL (as opposed to the SPL or U-Boot\n\t\tproper). Code that needs stage-specific behavior should check\n\t\tthis.\n\n- CONFIG_SYS_MPC85XX_NO_RESETVEC\n\t\tOnly for 85xx systems. If this variable is specified, the section\n\t\t.resetvec is not kept and the section .bootpg is placed in the\n\t\tprevious 4k of the .text section.\n\n- CONFIG_ARCH_MAP_SYSMEM\n\t\tGenerally U-Boot (and in particular the md command) uses\n\t\teffective address. It is therefore not necessary to regard\n\t\tU-Boot address as virtual addresses that need to be translated\n\t\tto physical addresses. However, sandbox requires this, since\n\t\tit maintains its own little RAM buffer which contains all\n\t\taddressable memory. This option causes some memory accesses\n\t\tto be mapped through map_sysmem() / unmap_sysmem().\n\n- CONFIG_X86_RESET_VECTOR\n\t\tIf defined, the x86 reset vector code is included. This is not\n\t\tneeded when U-Boot is running from Coreboot.\n\n- CONFIG_SYS_NAND_NO_SUBPAGE_WRITE\n\t\tOption to disable subpage write in NAND driver\n\t\tdriver that uses this:\n\t\tdrivers/mtd/nand/raw/davinci_nand.c\n\nFreescale QE/FMAN Firmware Support:\n-----------------------------------\n\nThe Freescale QUICCEngine (QE) and Frame Manager (FMAN) both support the\nloading of \"firmware\", which is encoded in the QE firmware binary format.\nThis firmware often needs to be loaded during U-Boot booting, so macros\nare used to identify the storage device (NOR flash, SPI, etc) and the address\nwithin that device.\n\n- CONFIG_SYS_FMAN_FW_ADDR\n\tThe address in the storage device where the FMAN microcode is located.  The\n\tmeaning of this address depends on which CONFIG_SYS_QE_FMAN_FW_IN_xxx macro\n\tis also specified.\n\n- CONFIG_SYS_QE_FW_ADDR\n\tThe address in the storage device where the QE microcode is located.  The\n\tmeaning of this address depends on which CONFIG_SYS_QE_FMAN_FW_IN_xxx macro\n\tis also specified.\n\n- CONFIG_SYS_QE_FMAN_FW_LENGTH\n\tThe maximum possible size of the firmware.  The firmware binary format\n\thas a field that specifies the actual size of the firmware, but it\n\tmight not be possible to read any part of the firmware unless some\n\tlocal storage is allocated to hold the entire firmware first.\n\n- CONFIG_SYS_QE_FMAN_FW_IN_NOR\n\tSpecifies that QE/FMAN firmware is located in NOR flash, mapped as\n\tnormal addressable memory via the LBC.  CONFIG_SYS_FMAN_FW_ADDR is the\n\tvirtual address in NOR flash.\n\n- CONFIG_SYS_QE_FMAN_FW_IN_NAND\n\tSpecifies that QE/FMAN firmware is located in NAND flash.\n\tCONFIG_SYS_FMAN_FW_ADDR is the offset within NAND flash.\n\n- CONFIG_SYS_QE_FMAN_FW_IN_MMC\n\tSpecifies that QE/FMAN firmware is located on the primary SD/MMC\n\tdevice.  CONFIG_SYS_FMAN_FW_ADDR is the byte offset on that device.\n\n- CONFIG_SYS_QE_FMAN_FW_IN_REMOTE\n\tSpecifies that QE/FMAN firmware is located in the remote (master)\n\tmemory space.\tCONFIG_SYS_FMAN_FW_ADDR is a virtual address which\n\tcan be mapped from slave TLB-\u003eslave LAW-\u003eslave SRIO or PCIE outbound\n\twindow-\u003emaster inbound window-\u003emaster LAW-\u003ethe ucode address in\n\tmaster's memory space.\n\nFreescale Layerscape Management Complex Firmware Support:\n---------------------------------------------------------\nThe Freescale Layerscape Management Complex (MC) supports the loading of\n\"firmware\".\nThis firmware often needs to be loaded during U-Boot booting, so macros\nare used to identify the storage device (NOR flash, SPI, etc) and the address\nwithin that device.\n\n- CONFIG_FSL_MC_ENET\n\tEnable the MC driver for Layerscape SoCs.\n\nFreescale Layerscape Debug Server Support:\n-------------------------------------------\nThe Freescale Layerscape Debug Server Support supports the loading of\n\"Debug Server firmware\" and triggering SP boot-rom.\nThis firmware often needs to be loaded during U-Boot booting.\n\n- CONFIG_SYS_MC_RSV_MEM_ALIGN\n\tDefine alignment of reserved memory MC requires\n\nReproducible builds\n-------------------\n\nIn order to achieve reproducible builds, timestamps used in the U-Boot build\nprocess have to be set to a fixed value.\n\nThis is done using the SOURCE_DATE_EPOCH environment variable.\nSOURCE_DATE_EPOCH is to be set on the build host's shell, not as a configuration\noption for U-Boot or an environment variable in U-Boot.\n\nSOURCE_DATE_EPOCH should be set to a number of seconds since the epoch, in UTC.\n\nBuilding the Software:\n======================\n\nBuilding U-Boot has been tested in several native build environments\nand in many different cross environments. Of course we cannot support\nall possibly existing versions of cross development tools in all\n(potentially obsolete) versions. In case of tool chain problems we\nrecommend to use the ELDK (see https://www.denx.de/wiki/DULG/ELDK)\nwhich is extensively used to build and test U-Boot.\n\nIf you are not using a native environment, it is assumed that you\nhave GNU cross compiling tools available in your path. In this case,\nyou must set the environment variable CROSS_COMPILE in your shell.\nNote that no changes to the Makefile or any other source files are\nnecessary. For example using the ELDK on a 4xx CPU, please enter:\n\n\t$ CROSS_COMPILE=ppc_4xx-\n\t$ export CROSS_COMPILE\n\nU-Boot is intended to be simple to build. After installing the\nsources you must configure U-Boot for one specific board type. This\nis done by typing:\n\n\tmake NAME_defconfig\n\nwhere \"NAME_defconfig\" is the name of one of the existing configu-\nrations; see configs/*_defconfig for supported names.\n\nNote: for some boards special configuration names may exist; check if\n      additional information is available from the board vendor; for\n      instance, the TQM823L systems are available without (standard)\n      or with LCD support. You can select such additional \"features\"\n      when choosing the configuration, i. e.\n\n      make TQM823L_defconfig\n\t- will configure for a plain TQM823L, i. e. no LCD support\n\n      make TQM823L_LCD_defconfig\n\t- will configure for a TQM823L with U-Boot console on LCD\n\n      etc.\n\n\nFinally, type \"make all\", and you should get some working U-Boot\nimages ready for download to / installation on your system:\n\n- \"u-boot.bin\" is a raw binary image\n- \"u-boot\" is an image in ELF binary format\n- \"u-boot.srec\" is in Motorola S-Record format\n\nBy default the build is performed locally and the objects are saved\nin the source directory. One of the two methods can be used to change\nthis behavior and build U-Boot to some external directory:\n\n1. Add O= to the make command line invocations:\n\n\tmake O=/tmp/build distclean\n\tmake O=/tmp/build NAME_defconfig\n\tmake O=/tmp/build all\n\n2. Set environment variable KBUILD_OUTPUT to point to the desired location:\n\n\texport KBUILD_OUTPUT=/tmp/build\n\tmake distclean\n\tmake NAME_defconfig\n\tmake all\n\nNote that the command line \"O=\" setting overrides the KBUILD_OUTPUT environment\nvariable.\n\nUser specific CPPFLAGS, AFLAGS and CFLAGS can be passed to the compiler by\nsetting the according environment variables KCPPFLAGS, KAFLAGS and KCFLAGS.\nFor example to treat all compiler warnings as errors:\n\n\tmake KCFLAGS=-Werror\n\nPlease be aware that the Makefiles assume you are using GNU make, so\nfor instance on NetBSD you might need to use \"gmake\" instead of\nnative \"make\".\n\n\nIf the system board that you have is not listed, then you will need\nto port U-Boot to your hardware platform. To do this, follow these\nsteps:\n\n1.  Create a new directory to hold your board specific code. Add any\n    files you need. In your board directory, you will need at least\n    the \"Makefile\" and a \"\u003cboard\u003e.c\".\n2.  Create a new configuration file \"include/configs/\u003cboard\u003e.h\" for\n    your board.\n3.  If you're porting U-Boot to a new CPU, then also create a new\n    directory to hold your CPU specific code. Add any files you need.\n4.  Run \"make \u003cboard\u003e_defconfig\" with your new name.\n5.  Type \"make\", and you should get a working \"u-boot.srec\" file\n    to be installed on your target system.\n6.  Debug and solve any problems that might arise.\n    [Of course, this last step is much harder than it sounds.]\n\n\nTesting of U-Boot Modifications, Ports to New Hardware, etc.:\n==============================================================\n\nIf you have modified U-Boot sources (for instance added a new board\nor support for new devices, a new CPU, etc.) you are expected to\nprovide feedback to the other developers. The feedback normally takes\nthe form of a \"patch\", i.e. a context diff against a certain (latest\nofficial or latest in the git repository) version of U-Boot sources.\n\nBut before you submit such a patch, please verify that your modifi-\ncation did not break existing code. At least make sure that *ALL* of\nthe supported boards compile WITHOUT ANY compiler warnings. To do so,\njust run the buildman script (tools/buildman/buildman), which will\nconfigure and build U-Boot for ALL supported system. Be warned, this\nwill take a while. Please see the buildman README, or run 'buildman -H'\nfor documentation.\n\n\nSee also \"U-Boot Porting Guide\" below.\n\n\nMonitor Commands - Overview:\n============================\n\ngo\t- start application at address 'addr'\nrun\t- run commands in an environment variable\nbootm\t- boot application image from memory\nbootp\t- boot image via network using BootP/TFTP protocol\nbootz   - boot zImage from memory\ntftpboot- boot image via network using TFTP protocol\n\t       and env variables \"ipaddr\" and \"serverip\"\n\t       (and eventually \"gatewayip\")\ntftpput - upload a file via network using TFTP protocol\nrarpboot- boot image via network using RARP/TFTP protocol\ndiskboot- boot from IDE devicebootd   - boot default, i.e., run 'bootcmd'\nloads\t- load S-Record file over serial line\nloadb\t- load binary file over serial line (kermit mode)\nmd\t- memory display\nmm\t- memory modify (auto-incrementing)\nnm\t- memory modify (constant address)\nmw\t- memory write (fill)\nms\t- memory search\ncp\t- memory copy\ncmp\t- memory compare\ncrc32\t- checksum calculation\ni2c\t- I2C sub-system\nsspi\t- SPI utility commands\nbase\t- print or set address offset\nprintenv- print environment variables\nsetenv\t- set environment variables\nsaveenv - save environment variables to persistent storage\nprotect - enable or disable FLASH write protection\nerase\t- erase FLASH memory\nflinfo\t- print FLASH memory information\nnand\t- NAND memory operations (see doc/README.nand)\nbdinfo\t- print Board Info structure\niminfo\t- print header information for application image\nconinfo - print console devices and informations\nide\t- IDE sub-system\nloop\t- infinite loop on address range\nloopw\t- infinite write loop on address range\nmtest\t- simple RAM test\nicache\t- enable or disable instruction cache\ndcache\t- enable or disable data cache\nreset\t- Perform RESET of the CPU\necho\t- echo args to console\nversion - print monitor version\nhelp\t- print online help\n?\t- alias for 'help'\n\n\nMonitor Commands - Detailed Description:\n========================================\n\nTODO.\n\nFor now: just type \"help \u003ccommand\u003e\".\n\n\nEnvironment Variables:\n======================\n\nU-Boot supports user configuration using Environment Variables which\ncan be made persistent by saving to Flash memory.\n\nEnvironment Variables are set using \"setenv\", printed using\n\"printenv\", and saved to Flash using \"saveenv\". Using \"setenv\"\nwithout a value can be used to delete a variable from the\nenvironment. As long as you don't save the environment you are\nworking with an in-memory copy. In case the Flash area containing the\nenvironment is erased by accident, a default environment is provided.\n\nSome configuration options can be set using Environment Variables.\n\nList of environment variables (most likely not complete):\n\n  baudrate\t- see CONFIG_BAUDRATE\n\n  bootdelay\t- see CONFIG_BOOTDELAY\n\n  bootcmd\t- see CONFIG_BOOTCOMMAND\n\n  bootargs\t- Boot arguments when booting an RTOS image\n\n  bootfile\t- Name of the image to load with TFTP\n\n  bootm_low\t- Memory range available for image processing in the bootm\n\t\t  command can be restricted. This variable is given as\n\t\t  a hexadecimal number and defines lowest address allowed\n\t\t  for use by the bootm command. See also \"bootm_size\"\n\t\t  environment variable. Address defined by \"bootm_low\" is\n\t\t  also the base of the initial memory mapping for the Linux\n\t\t  kernel -- see the description of CONFIG_SYS_BOOTMAPSZ and\n\t\t  bootm_mapsize.\n\n  bootm_mapsize - Size of the initial memory mapping for the Linux kernel.\n\t\t  This variable is given as a hexadecimal number and it\n\t\t  defines the size of the memory region starting at base\n\t\t  address bootm_low that is accessible by the Linux kernel\n\t\t  during early boot.  If unset, CONFIG_SYS_BOOTMAPSZ is used\n\t\t  as the default value if it is defined, and bootm_size is\n\t\t  used otherwise.\n\n  bootm_size\t- Memory range available for image processing in the bootm\n\t\t  command can be restricted. This variable is given as\n\t\t  a hexadecimal number and defines the size of the region\n\t\t  allowed for use by the bootm command. See also \"bootm_low\"\n\t\t  environment variable.\n\n  bootstopkeysha256, bootdelaykey, bootstopkey\t- See README.autoboot\n\n  updatefile\t- Location of the software update file on a TFTP server, used\n\t\t  by the automatic software update feature. Please refer to\n\t\t  documentation in doc/README.update for more details.\n\n  autoload\t- if set to \"no\" (any string beginning with 'n'),\n\t\t  \"bootp\" will just load perform a lookup of the\n\t\t  configuration from the BOOTP server, but not try to\n\t\t  load any image using TFTP\n\n  autostart\t- if set to \"yes\", an image loaded using the \"bootp\",\n\t\t  \"rarpboot\", \"tftpboot\" or \"diskboot\" commands will\n\t\t  be automatically started (by internally calling\n\t\t  \"bootm\")\n\n\t\t  If set to \"no\", a standalone image passed to the\n\t\t  \"bootm\" command will be copied to the load address\n\t\t  (and eventually uncompressed), but NOT be started.\n\t\t  This can be used to load and uncompress arbitrary\n\t\t  data.\n\n  fdt_high\t- if set this restricts the maximum address that the\n\t\t  flattened device tree will be copied into upon boot.\n\t\t  For example, if you have a system with 1 GB memory\n\t\t  at physical address 0x10000000, while Linux kernel\n\t\t  only recognizes the first 704 MB as low memory, you\n\t\t  may need to set fdt_high as 0x3C000000 to have the\n\t\t  device tree blob be copied to the maximum address\n\t\t  of the 704 MB low memory, so that Linux kernel can\n\t\t  access it during the boot procedure.\n\n\t\t  If this is set to the special value 0xFFFFFFFF then\n\t\t  the fdt will not be copied at all on boot.  For this\n\t\t  to work it must reside in writable memory, have\n\t\t  sufficient padding on the end of it for u-boot to\n\t\t  add the information it needs into it, and the memory\n\t\t  must be accessible by the kernel.\n\n  fdtcontroladdr- if set this is the address of the control flattened\n\t\t  device tree used by U-Boot when CONFIG_OF_CONTROL is\n\t\t  defined.\n\n  i2cfast\t- (PPC405GP|PPC405EP only)\n\t\t  if set to 'y' configures Linux I2C driver for fast\n\t\t  mode (400kHZ). This environment variable is used in\n\t\t  initialization code. So, for changes to be effective\n\t\t  it must be saved and board must be reset.\n\n  initrd_high\t- restrict positioning of initrd images:\n\t\t  If this variable is not set, initrd images will be\n\t\t  copied to the highest possible address in RAM; this\n\t\t  is usually what you want since it allows for\n\t\t  maximum initrd size. If for some reason you want to\n\t\t  make sure that the initrd image is loaded below the\n\t\t  CONFIG_SYS_BOOTMAPSZ limit, you can set this environment\n\t\t  variable to a value of \"no\" or \"off\" or \"0\".\n\t\t  Alternatively, you can set it to a maximum upper\n\t\t  address to use (U-Boot will still check that it\n\t\t  does not overwrite the U-Boot stack and data).\n\n\t\t  For instance, when you have a system with 16 MB\n\t\t  RAM, and want to reserve 4 MB from use by Linux,\n\t\t  you can do this by adding \"mem=12M\" to the value of\n\t\t  the \"bootargs\" variable. However, now you must make\n\t\t  sure that the initrd image is placed in the first\n\t\t  12 MB as well - this can be done with\n\n\t\t  setenv initrd_high 00c00000\n\n\t\t  If you set initrd_high to 0xFFFFFFFF, this is an\n\t\t  indication to U-Boot that all addresses are legal\n\t\t  for the Linux kernel, including addresses in flash\n\t\t  memory. In this case U-Boot will NOT COPY the\n\t\t  ramdisk at all. This may be useful to reduce the\n\t\t  boot time on your system, but requires that this\n\t\t  feature is supported by your Linux kernel.\n\n  ipaddr\t- IP address; needed for tftpboot command\n\n  loadaddr\t- Default load address for commands like \"bootp\",\n\t\t  \"rarpboot\", \"tftpboot\", \"loadb\" or \"diskboot\"\n\n  loads_echo\t- see CONFIG_LOADS_ECHO\n\n  serverip\t- TFTP server IP address; needed for tftpboot command\n\n  bootretry\t- see CONFIG_BOOT_RETRY_TIME\n\n  bootdelaykey\t- see CONFIG_AUTOBOOT_DELAY_STR\n\n  bootstopkey\t- see CONFIG_AUTOBOOT_STOP_STR\n\n  ethprime\t- controls which interface is used first.\n\n  ethact\t- controls which interface is currently active.\n\t\t  For example you can do the following\n\n\t\t  =\u003e setenv ethact FEC\n\t\t  =\u003e ping 192.168.0.1 # traffic sent on FEC\n\t\t  =\u003e setenv ethact SCC\n\t\t  =\u003e ping 10.0.0.1 # traffic sent on SCC\n\n  ethrotate\t- When set to \"no\" U-Boot does not go through all\n\t\t  available network interfaces.\n\t\t  It just stays at the currently selected interface.\n\n  netretry\t- When set to \"no\" each network operation will\n\t\t  either succeed or fail without retrying.\n\t\t  When set to \"once\" the network operation will\n\t\t  fail when all the available network interfaces\n\t\t  are tried once without success.\n\t\t  Useful on scripts which control the retry operation\n\t\t  themselves.\n\n  npe_ucode\t- set load address for the NPE microcode\n\n  silent_linux  - If set then Linux will be told to boot silently, by\n\t\t  changing the console to be empty. If \"yes\" it will be\n\t\t  made silent. If \"no\" it will not be made silent. If\n\t\t  unset, then it will be made silent if the U-Boot console\n\t\t  is silent.\n\n  tftpsrcp\t- If this is set, the value is used for TFTP's\n\t\t  UDP source port.\n\n  tftpdstp\t- If this is set, the value is used for TFTP's UDP\n\t\t  destination port instead of the Well Know Port 69.\n\n  tftpblocksize - Block size to use for TFTP transfers; if not set,\n\t\t  we use the TFTP server's default block size\n\n  tftptimeout\t- Retransmission timeout for TFTP packets (in milli-\n\t\t  seconds, minimum value is 1000 = 1 second). Defines\n\t\t  when a packet is considered to be lost so it has to\n\t\t  be retransmitted. The default is 5000 = 5 seconds.\n\t\t  Lowering this value may make downloads succeed\n\t\t  faster in networks with high packet loss rates or\n\t\t  with unreliable TFTP servers.\n\n  tftptimeoutcountmax\t- maximum count of TFTP timeouts (no\n\t\t  unit, minimum value = 0). Defines how many timeouts\n\t\t  can happen during a single file transfer before that\n\t\t  transfer is aborted. The default is 10, and 0 means\n\t\t  'no timeouts allowed'. Increasing this value may help\n\t\t  downloads succeed with high packet loss rates, or with\n\t\t  unreliable TFTP servers or client hardware.\n\n  tftpwindowsize\t- if this is set, the value is used for TFTP's\n\t\t  window size as described by RFC 7440.\n\t\t  This means the count of blocks we can receive before\n\t\t  sending ack to server.\n\n  vlan\t\t- When set to a value \u003c 4095 the traffic over\n\t\t  Ethernet is encapsulated/received over 802.1q\n\t\t  VLAN tagged frames.\n\n  bootpretryperiod\t- Period during which BOOTP/DHCP sends retries.\n\t\t  Unsigned value, in milliseconds. If not set, the period will\n\t\t  be either the default (28000), or a value based on\n\t\t  CONFIG_NET_RETRY_COUNT, if defined. This value has\n\t\t  precedence over the valu based on CONFIG_NET_RETRY_COUNT.\n\n  memmatches\t- Number of matches found by the last 'ms' command, in hex\n\n  memaddr\t- Address of the last match found by the 'ms' command, in hex,\n\t\t  or 0 if none\n\n  mempos\t- Index position of the last match found by the 'ms' command,\n\t\t  in units of the size (.b, .w, .l) of the search\n\n  zbootbase\t- (x86 only) Base address of the bzImage 'setup' block\n\n  zbootaddr\t- (x86 only) Address of the loaded bzImage, typically\n\t\t  BZIMAGE_LOAD_ADDR which is 0x100000\n\nThe following image location variables contain the location of images\nused in booting. The \"Image\" column gives the role of the image and is\nnot an environment variable name. The other columns are environment\nvariable names. \"File Name\" gives the name of the file on a TFTP\nserver, \"RAM Address\" gives the location in RAM the image will be\nloaded to, and \"Flash Location\" gives the image's address in NOR\nflash or offset in NAND flash.\n\n*Note* - these variables don't have to be defined for all boards, some\nboards currently use other variables for these purposes, and some\nboards use these variables for other purposes.\n\nImage\t\t    File Name\t     RAM Address       Flash Location\n-----\t\t    ---------\t     -----------       --------------\nu-boot\t\t    u-boot\t     u-boot_addr_r     u-boot_addr\nLinux kernel\t    bootfile\t     kernel_addr_r     kernel_addr\ndevice tree blob    fdtfile\t     fdt_addr_r\t       fdt_addr\nramdisk\t\t    ramdiskfile\t     ramdisk_addr_r    ramdisk_addr\n\nThe following environment variables may be used and automatically\nupdated by the network boot commands (\"bootp\" and \"rarpboot\"),\ndepending the information provided by your boot server:\n\n  bootfile\t- see above\n  dnsip\t\t- IP address of your Domain Name Server\n  dnsip2\t- IP address of your secondary Domain Name Server\n  gatewayip\t- IP address of the Gateway (Router) to use\n  hostname\t- Target hostname\n  ipaddr\t- see above\n  netmask\t- Subnet Mask\n  rootpath\t- Pathname of the root filesystem on the NFS server\n  serverip\t- see above\n\n\nThere are two special Environment Variables:\n\n  serial#\t- contains hardware identification information such\n\t\t  as type string and/or serial number\n  ethaddr\t- Ethernet address\n\nThese variables can be set only once (usually during manufacturing of\nthe board). U-Boot refuses to delete or overwrite these variables\nonce they have been set once.\n\n\nFurther special Environment Variables:\n\n  ver\t\t- Contains the U-Boot version string as printed\n\t\t  with the \"version\" command. This variable is\n\t\t  readonly (see CONFIG_VERSION_VARIABLE).\n\n\nPlease note that changes to some configuration parameters may take\nonly effect after the next boot (yes, that's just like Windoze :-).\n\n\nCallback functions for environment variables:\n---------------------------------------------\n\nFor some environment variables, the behavior of u-boot needs to change\nwhen their values are changed.  This functionality allows functions to\nbe associated with arbitrary variables.  On creation, overwrite, or\ndeletion, the callback will provide the opportunity for some side\neffect to happen or for the change to be rejected.\n\nThe callbacks are named and associated with a function using the\nU_BOOT_ENV_CALLBACK macro in your board or driver code.\n\nThese callbacks are associated with variables in one of two ways.  The\nstatic list can be added to by defining CONFIG_ENV_CALLBACK_LIST_STATIC\nin the board configuration to a string that defines a list of\nassociations.  The list must be in the following format:\n\n\tentry = variable_name[:callback_name]\n\tlist = entry[,list]\n\nIf the callback name is not specified, then the callback is deleted.\nSpaces are also allowed anywhere in the list.\n\nCallbacks can also be associated by defining the \".callbacks\" variable\nwith the same list format above.  Any association in \".callbacks\" will\noverride any association in the static list. You can define\nCONFIG_ENV_CALLBACK_LIST_DEFAULT to a list (string) to define the\n\".callbacks\" environment variable in the default or embedded environment.\n\nIf CONFIG_REGEX is defined, the variable_name above is evaluated as a\nregular expression. This allows multiple variables to be connected to\nthe same callback without explicitly listing them all out.\n\nThe signature of the callback functions is:\n\n    int callback(const char *name, const char *value, enum env_op op, int flags)\n\n* name - changed environment variable\n* value - new value of the environment variable\n* op - operation (create, overwrite, or delete)\n* flags - attributes of the environment variable change, see flags H_* in\n  include/search.h\n\nThe return value is 0 if the variable change is accepted and 1 otherwise.\n\nCommand Line Parsing:\n=====================\n\nThere are two different command line parsers available with U-Boot:\nthe old \"simple\" one, and the much more powerful \"hush\" shell:\n\nOld, simple command line parser:\n--------------------------------\n\n- supports environment variables (through setenv / saveenv commands)\n- several commands on one line, separated by ';'\n- variable substitution using \"... ${name} ...\" syntax\n- special characters ('$', ';') can be escaped by prefixing with '\\',\n  for example:\n\tsetenv bootcmd bootm \\${address}\n- You can also escape text by enclosing in single apostrophes, for example:\n\tsetenv addip 'setenv bootargs $bootargs ip=$ipaddr:$serverip:$gatewayip:$netmask:$hostname::off'\n\nHush shell:\n-----------\n\n- similar to Bourne shell, with control structures like\n  if...then...else...fi, for...do...done; while...do...done,\n  until...do...done, ...\n- supports environment (\"global\") variables (through setenv / saveenv\n  commands) and local shell variables (through standard shell syntax\n  \"name=value\"); only environment variables can be used with \"run\"\n  command\n\nGeneral rules:\n--------------\n\n(1) If a command line (or an environment variable executed by a \"run\"\n    command) contains several commands separated by semicolon, and\n    one of these commands fails, then the remaining commands will be\n    executed anyway.\n\n(2) If you execute several variables with one call to run (i. e.\n    calling run with a list of variables as arguments), any failing\n    command will cause \"run\" to terminate, i. e. the remaining\n    variables are not executed.\n\nNote for Redundant Ethernet Interfaces:\n=======================================\n\nSome boards come with redundant Ethernet interfaces; U-Boot supports\nsuch configurations and is capable of automatic selection of a\n\"working\" interface when needed. MAC assignment works as follows:\n\nNetwork interfaces are numbered eth0, eth1, eth2, ... Corresponding\nMAC addresses can be stored in the environment as \"ethaddr\" (=\u003eeth0),\n\"eth1addr\" (=\u003eeth1), \"eth2addr\", ...\n\nIf the network interface stores some valid MAC address (for instance\nin SROM), this is used as default address if there is NO correspon-\nding setting in the environment; if the corresponding environment\nvariable is set, this overrides the settings in the card; that means:\n\no If the SROM has a valid MAC address, and there is no address in the\n  environment, the SROM's address is used.\n\no If there is no valid address in the SROM, and a definition in the\n  environment exists, then the value from the environment variable is\n  used.\n\no If both the SROM and the environment contain a MAC address, and\n  both addresses are the same, this MAC address is used.\n\no If both the SROM and the environment contain a MAC address, and the\n  addresses differ, the value from the environment is used and a\n  warning is printed.\n\no If neither SROM nor the environment contain a MAC address, an error\n  is raised. If CONFIG_NET_RANDOM_ETHADDR is defined, then in this case\n  a random, locally-assigned MAC is used.\n\nIf Ethernet drivers implement the 'write_hwaddr' function, valid MAC addresses\nwill be programmed into hardware as part of the initialization process.\t This\nmay be skipped by setting the appropriate 'ethmacskip' environment variable.\nThe naming convention is as follows:\n\"ethmacskip\" (=\u003eeth0), \"eth1macskip\" (=\u003eeth1) etc.\n\nImage Formats:\n==============\n\nU-Boot is capable of booting (and performing other auxiliary operations on)\nimages in two formats:\n\nNew uImage format (FIT)\n-----------------------\n\nFlexible and powerful format based on Flattened Image Tree -- FIT (similar\nto Flattened Device Tree). It allows the use of images with multiple\ncomponents (several kernels, ramdisks, etc.), with contents protected by\nSHA1, MD5 or CRC32. More details are found in the doc/uImage.FIT directory.\n\n\nOld uImage format\n-----------------\n\nOld image format is based on binary files which can be basically anything,\npreceded by a special header; see the definitions in include/image.h for\ndetails; basically, the header defines the following image properties:\n\n* Target Operating System (Provisions for OpenBSD, NetBSD, FreeBSD,\n  4.4BSD, Linux, SVR4, Esix, Solaris, Irix, SCO, Dell, NCR, VxWorks,\n  LynxOS, pSOS, QNX, RTEMS, INTEGRITY;\n  Currently supported: Linux, NetBSD, VxWorks, QNX, RTEMS, LynxOS,\n  INTEGRITY).\n* Target CPU Architecture (Provisions for Alpha, ARM, Intel x86,\n  IA64, MIPS, NDS32, Nios II, PowerPC, IBM S390, SuperH, Sparc, Sparc 64 Bit;\n  Currently supported: ARM, Intel x86, MIPS, NDS32, Nios II, PowerPC).\n* Compression Type (uncompressed, gzip, bzip2)\n* Load Address\n* Entry Point\n* Image Name\n* Image Timestamp\n\nThe header is marked by a special Magic Number, and both the header\nand the data portions of the image are secured against corruption by\nCRC32 checksums.\n\n\nLinux Support:\n==============\n\nAlthough U-Boot should support any OS or standalone application\neasily, the main focus has always been on Linux during the design of\nU-Boot.\n\nU-Boot includes many features that so far have been part of some\nspecial \"boot loader\" code within the Linux kernel. Also, any\n\"initrd\" images to be used are no longer part of one big Linux image;\ninstead, kernel and \"initrd\" are separate images. This implementation\nserves several purposes:\n\n- the same features can be used for other OS or standalone\n  applications (for instance: using compressed images to reduce the\n  Flash memory footprint)\n\n- it becomes much easier to port new Linux kernel versions because\n  lots of low-level, hardware dependent stuff are done by U-Boot\n\n- the same Linux kernel image can now be used with different \"initrd\"\n  images; of course this also means that different kernel images can\n  be run with the same \"initrd\". This makes testing easier (you don't\n  have to build a new \"zImage.initrd\" Linux image when you just\n  change a file in your \"initrd\"). Also, a field-upgrade of the\n  software is easier now.\n\n\nLinux HOWTO:\n============\n\nPorting Linux to U-Boot based systems:\n---------------------------------------\n\nU-Boot cannot save you from doing all the necessary modifications to\nconfigure the Linux device drivers for use with your target hardware\n(no, we don't intend to provide a full virtual machine interface to\nLinux :-).\n\nBut now you can ignore ALL boot loader code (in arch/powerpc/mbxboot).\n\nJust make sure your machine specific header file (for instance\ninclude/asm-ppc/tqm8xx.h) includes the same definition of the Board\nInformation structure as we define in include/asm-\u003carch\u003e/u-boot.h,\nand make sure that your definition of IMAP_ADDR uses the same value\nas your U-Boot configuration in CONFIG_SYS_IMMR.\n\nNote that U-Boot now has a driver model, a unified model for drivers.\nIf you are adding a new driver, plumb it into driver model. If there\nis no uclass available, you are encouraged to create one. See\ndoc/driver-model.\n\n\nConfiguring the Linux kernel:\n-----------------------------\n\nNo specific requirements for U-Boot. Make sure you have some root\ndevice (initial ramdisk, NFS) for your target system.\n\n\nBuilding a Linux Image:\n-----------------------\n\nWith U-Boot, \"normal\" build targets like \"zImage\" or \"bzImage\" are\nnot used. If you use recent kernel source, a new build target\n\"uImage\" will exist which automatically builds an image usable by\nU-Boot. Most older kernels also have support for a \"pImage\" target,\nwhich was introduced for our predecessor project PPCBoot and uses a\n100% compatible format.\n\nExample:\n\n\tmake TQM850L_defconfig\n\tmake oldconfig\n\tmake dep\n\tmake uImage\n\nThe \"uImage\" build target uses a special tool (in 'tools/mkimage') to\nencapsulate a compressed Linux kernel image with header\t information,\nCRC32 checksum etc. for use with U-Boot. This is what we are doing:\n\n* build a standard \"vmlinux\" kernel image (in ELF binary format):\n\n* convert the kernel into a raw binary image:\n\n\t${CROSS_COMPILE}-objcopy -O binary \\\n\t\t\t\t -R .note -R .comment \\\n\t\t\t\t -S vmlinux linux.bin\n\n* compress the binary image:\n\n\tgzip -9 linux.bin\n\n* package compressed binary image for U-Boot:\n\n\tmkimage -A ppc -O linux -T kernel -C gzip \\\n\t\t-a 0 -e 0 -n \"Linux Kernel Image\" \\\n\t\t-d linux.bin.gz uImage\n\n\nThe \"mkimage\" tool can also be used to create ramdisk images for use\nwith U-Boot, either separated from the Linux kernel image, or\ncombined into one file. \"mkimage\" encapsulates the images with a 64\nbyte header containing information about target architecture,\noperating system, image type, compression method, entry points, time\nstamp, CRC32 checksums, etc.\n\n\"mkimage\" can be called in two ways: to verify existing images and\nprint the header information, or to build new images.\n\nIn the first form (with \"-l\" option) mkimage lists the information\ncontained in the header of an existing U-Boot image; this includes\nchecksum verification:\n\n\ttools/mkimage -l image\n\t  -l ==\u003e list image header information\n\nThe second form (with \"-d\" option) is used to build a U-Boot image\nfrom a \"data file\" which is used as image payload:\n\n\ttools/mkimage -A arch -O os -T type -C comp -a addr -e ep \\\n\t\t      -n name -d data_file image\n\t  -A ==\u003e set architecture to 'arch'\n\t  -O ==\u003e set operating system to 'os'\n\t  -T ==\u003e set image type to 'type'\n\t  -C ==\u003e set compression type 'comp'\n\t  -a ==\u003e set load address to 'addr' (hex)\n\t  -e ==\u003e set entry point to 'ep' (hex)\n\t  -n ==\u003e set image name to 'name'\n\t  -d ==\u003e use image data from 'datafile'\n\nRight now, all Linux kernels for PowerPC systems use the same load\naddress (0x00000000), but the entry point address depends on the\nkernel version:\n\n- 2.2.x kernels have the entry point at 0x0000000C,\n- 2.3.x and later kernels have the entry point at 0x00000000.\n\nSo a typical call to build a U-Boot image would read:\n\n\t-\u003e tools/mkimage -n '2.4.4 kernel for TQM850L' \\\n\t\u003e -A ppc -O linux -T kernel -C gzip -a 0 -e 0 \\\n\t\u003e -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz \\\n\t\u003e examples/uImage.TQM850L\n\tImage Name:   2.4.4 kernel for TQM850L\n\tCreated:      Wed Jul 19 02:34:59 2000\n\tImage Type:   PowerPC Linux Kernel Image (gzip compressed)\n\tData Size:    335725 Bytes = 327.86 kB = 0.32 MB\n\tLoad Address: 0x00000000\n\tEntry Point:  0x00000000\n\nTo verify the contents of the image (or check for corruption):\n\n\t-\u003e tools/mkimage -l examples/uImage.TQM850L\n\tImage Name:   2.4.4 kernel for TQM850L\n\tCreated:      Wed Jul 19 02:34:59 2000\n\tImage Type:   PowerPC Linux Kernel Image (gzip compressed)\n\tData Size:    335725 Bytes = 327.86 kB = 0.32 MB\n\tLoad Address: 0x00000000\n\tEntry Point:  0x00000000\n\nNOTE: for embedded systems where boot time is critical you can trade\nspeed for memory and install an UNCOMPRESSED image instead: this\nneeds more space in Flash, but boots much faster since it does not\nneed to be uncompressed:\n\n\t-\u003e gunzip /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz\n\t-\u003e tools/mkimage -n '2.4.4 kernel for TQM850L' \\\n\t\u003e -A ppc -O linux -T kernel -C none -a 0 -e 0 \\\n\t\u003e -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux \\\n\t\u003e examples/uImage.TQM850L-uncompressed\n\tImage Name:   2.4.4 kernel for TQM850L\n\tCreated:      Wed Jul 19 02:34:59 2000\n\tImage Type:   PowerPC Linux Kernel Image (uncompressed)\n\tData Size:    792160 Bytes = 773.59 kB = 0.76 MB\n\tLoad Address: 0x00000000\n\tEntry Point:  0x00000000\n\n\nSimilar you can build U-Boot images from a 'ramdisk.image.gz' file\nwhen your kernel is intended to use an initial ramdisk:\n\n\t-\u003e tools/mkimage -n 'Simple Ramdisk Image' \\\n\t\u003e -A ppc -O linux -T ramdisk -C gzip \\\n\t\u003e -d /LinuxPPC/images/SIMPLE-ramdisk.image.gz examples/simple-initrd\n\tImage Name:   Simple Ramdisk Image\n\tCreated:      Wed Jan 12 14:01:50 2000\n\tImage Type:   PowerPC Linux RAMDisk Image (gzip compressed)\n\tData Size:    566530 Bytes = 553.25 kB = 0.54 MB\n\tLoad Address: 0x00000000\n\tEntry Point:  0x00000000\n\nThe \"dumpimage\" tool can be used to disassemble or list the contents of images\nbuilt by mkimage. See dumpimage's help output (-h) for details.\n\nInstalling a Linux Image:\n-------------------------\n\nTo downloading a U-Boot image over the serial (console) interface,\nyou must convert the image to S-Record format:\n\n\tobjcopy -I binary -O srec examples/image examples/image.srec\n\nThe 'objcopy' does not understand the information in the U-Boot\nimage header, so the resulting S-Record file will be relative to\naddress 0x00000000. To load it to a given address, you need to\nspecify the target address as 'offset' parameter with the 'loads'\ncommand.\n\nExample: install the image to address 0x40100000 (which on the\nTQM8xxL is in the first Flash bank):\n\n\t=\u003e erase 40100000 401FFFFF\n\n\t.......... done\n\tErased 8 sectors\n\n\t=\u003e loads 40100000\n\t## Ready for S-Record download ...\n\t~\u003eexamples/image.srec\n\t1 2 3 4 5 6 7 8 9 10 11 12 13 ...\n\t...\n\t15989 15990 15991 15992\n\t[file transfer complete]\n\t[connected]\n\t## Start Addr = 0x00000000\n\n\nYou can check the success of the download using the 'iminfo' command;\nthis includes a checksum verification so you can be sure no data\ncorruption happened:\n\n\t=\u003e imi 40100000\n\n\t## Checking Image at 40100000 ...\n\t   Image Name:\t 2.2.13 for initrd on TQM850L\n\t   Image Type:\t PowerPC Linux Kernel Image (gzip compressed)\n\t   Data Size:\t 335725 Bytes = 327 kB = 0 MB\n\t   Load Address: 00000000\n\t   Entry Point:\t 0000000c\n\t   Verifying Checksum ... OK\n\n\nBoot Linux:\n-----------\n\nThe \"bootm\" command is used to boot an application that is stored in\nmemory (RAM or Flash). In case of a Linux kernel image, the contents\nof the \"bootargs\" environment variable is passed to the kernel as\nparameters. You can check and modify this variable using the\n\"printenv\" and \"setenv\" commands:\n\n\n\t=\u003e printenv bootargs\n\tbootargs=root=/dev/ram\n\n\t=\u003e setenv bootargs root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2\n\n\t=\u003e printenv bootargs\n\tbootargs=root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2\n\n\t=\u003e bootm 40020000\n\t## Booting Linux kernel at 40020000 ...\n\t   Image Name:\t 2.2.13 for NFS on TQM850L\n\t   Image Type:\t PowerPC Linux Kernel Image (gzip compressed)\n\t   Data Size:\t 381681 Bytes = 372 kB = 0 MB\n\t   Load Address: 00000000\n\t   Entry Point:\t 0000000c\n\t   Verifying Checksum ... OK\n\t   Uncompressing Kernel Image ... OK\n\tLinux version 2.2.13 (wd@denx.local.net) (gcc version 2.95.2 19991024 (release)) #1 Wed Jul 19 02:35:17 MEST 2000\n\tBoot arguments: root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2\n\ttime_init: decrementer frequency = 187500000/60\n\tCalibrating delay loop... 49.77 BogoMIPS\n\tMemory: 15208k available (700k kernel code, 444k data, 32k init) [c0000000,c1000000]\n\t...\n\nIf you want to boot a Linux kernel with initial RAM disk, you pass\nthe memory addresses of both the kernel and the initrd image (PPBCOOT\nformat!) to the \"bootm\" command:\n\n\t=\u003e imi 40100000 40200000\n\n\t## Checking Image at 40100000 ...\n\t   Image Name:\t 2.2.13 for initrd on TQM850L\n\t   Image Type:\t PowerPC Linux Kernel Image (gzip compressed)\n\t   Data Size:\t 335725 Bytes = 327 kB = 0 MB\n\t   Load Address: 00000000\n\t   Entry Point:\t 0000000c\n\t   Verifying Checksum ... OK\n\n\t## Checking Image at 40200000 ...\n\t   Image Name:\t Simple Ramdisk Image\n\t   Image Type:\t PowerPC Linux RAMDisk Image (gzip compressed)\n\t   Data Size:\t 566530 Bytes = 553 kB = 0 MB\n\t   Load Address: 00000000\n\t   Entry Point:\t 00000000\n\t   Verifying Checksum ... OK\n\n\t=\u003e bootm 40100000 40200000\n\t## Booting Linux kernel at 40100000 ...\n\t   Image Name:\t 2.2.13 for initrd on TQM850L\n\t   Image Type:\t PowerPC Linux Kernel Image (gzip compressed)\n\t   Data Size:\t 335725 Bytes = 327 kB = 0 MB\n\t   Load Address: 00000000\n\t   Entry Point:\t 0000000c\n\t   Verifying Checksum ... OK\n\t   Uncompressing Kernel Image ... OK\n\t## Loading RAMDisk Image at 40200000 ...\n\t   Image Name:\t Simple Ramdisk Image\n\t   Image Type:\t PowerPC Linux RAMDisk Image (gzip compressed)\n\t   Data Size:\t 566530 Bytes = 553 kB = 0 MB\n\t   Load Address: 00000000\n\t   Entry Point:\t 00000000\n\t   Verifying Checksum ... OK\n\t   Loading Ramdisk ... OK\n\tLinux version 2.2.13 (wd@denx.local.net) (gcc version 2.95.2 19991024 (release)) #1 Wed Jul 19 02:32:08 MEST 2000\n\tBoot arguments: root=/dev/ram\n\ttime_init: decrementer frequency = 187500000/60\n\tCalibrating delay loop... 49.77 BogoMIPS\n\t...\n\tRAMDISK: Compressed image found at block 0\n\tVFS: Mounted root (ext2 filesystem).\n\n\tbash#\n\nBoot Linux and pass a flat device tree:\n-----------\n\nFirst, U-Boot must be compiled with the appropriate defines. See the section\ntitled \"Linux Kernel Interface\" above for a more in depth explanation. The\nfollowing is an example of how to start a kernel and pass an updated\nflat device tree:\n\n=\u003e print oftaddr\noftaddr=0x300000\n=\u003e print oft\noft=oftrees/mpc8540ads.dtb\n=\u003e tftp $oftaddr $oft\nSpeed: 1000, full duplex\nUsing TSEC0 device\nTFTP from server 192.168.1.1; our IP address is 192.168.1.101\nFilename 'oftrees/mpc8540ads.dtb'.\nLoad address: 0x300000\nLoading: #\ndone\nBytes transferred = 4106 (100a hex)\n=\u003e tftp $loadaddr $bootfile\nSpeed: 1000, full duplex\nUsing TSEC0 device\nTFTP from server 192.168.1.1; our IP address is 192.168.1.2\nFilename 'uImage'.\nLoad address: 0x200000\nLoading:############\ndone\nBytes transferred = 1029407 (fb51f hex)\n=\u003e print loadaddr\nloadaddr=200000\n=\u003e print oftaddr\noftaddr=0x300000\n=\u003e bootm $loadaddr - $oftaddr\n## Booting image at 00200000 ...\n   Image Name:\t Linux-2.6.17-dirty\n   Image Type:\t PowerPC Linux Kernel Image (gzip compressed)\n   Data Size:\t 1029343 Bytes = 1005.2 kB\n   Load Address: 00000000\n   Entry Point:\t 00000000\n   Verifying Checksum ... OK\n   Uncompressing Kernel Image ... OK\nBooting using flat device tree at 0x300000\nUsing MPC85xx ADS machine description\nMemory CAM mapping: CAM0=256Mb, CAM1=256Mb, CAM2=0Mb residual: 0Mb\n[snip]\n\n\nMore About U-Boot Image Types:\n------------------------------\n\nU-Boot supports the following image types:\n\n   \"Standalone Programs\" are directly runnable in the environment\n\tprovided by U-Boot; it is expected that (if they behave\n\twell) you can continue to work in U-Boot after return from\n\tthe Standalone Program.\n   \"OS Kernel Images\" are usually images of some Embedded OS which\n\twill take over control completely. Usually these programs\n\twill install their own set of exception handlers, device\n\tdrivers, set up the MMU, etc. - this means, that you cannot\n\texpect to re-enter U-Boot except by resetting the CPU.\n   \"RAMDisk Images\" are more or less just data blocks, and their\n\tparameters (address, size) are passed to an OS kernel that is\n\tbeing started.\n   \"Multi-File Images\" contain several images, typically an OS\n\t(Linux) kernel image and one or more data images like\n\tRAMDisks. This construct is useful for instance when you want\n\tto boot over the network using BOOTP etc., where the boot\n\tserver provides just a single image file, but you want to get\n\tfor instance an OS kernel and a RAMDisk image.\n\n\t\"Multi-File Images\" start with a list of image sizes, each\n\timage size (in bytes) specified by an \"uint32_t\" in network\n\tbyte order. This list is terminated by an \"(uint32_t)0\".\n\tImmediately after the terminating 0 follow the images, one by\n\tone, all aligned on \"uint32_t\" boundaries (size rounded up to\n\ta multiple of 4 bytes).\n\n   \"Firmware Images\" are binary images containing firmware (like\n\tU-Boot or FPGA images) which usually will be programmed to\n\tflash memory.\n\n   \"Script files\" are command sequences that will be executed by\n\tU-Boot's command interpreter; this feature is especially\n\tuseful when you configure U-Boot to use a real shell (hush)\n\tas command interpreter.\n\nBooting the Linux zImage:\n-------------------------\n\nOn some platforms, it's possible to boot Linux zImage. This is done\nusing the \"bootz\" command. The syntax of \"bootz\" command is the same\nas the syntax of \"bootm\" command.\n\nNote, defining the CONFIG_SUPPORT_RAW_INITRD allows user to supply\nkernel with raw initrd images. The syntax is slightly different, the\naddress of the initrd must be augmented by it's size, in the following\nformat: \"\u003cinitrd addres\u003e:\u003cinitrd size\u003e\".\n\n\nStandalone HOWTO:\n=================\n\nOne of the features of U-Boot is that you can dynamically load and\nrun \"standalone\" applications, which can use some resources of\nU-Boot like console I/O functions or interrupt services.\n\nTwo simple examples are included with the sources:\n\n\"Hello World\" Demo:\n-------------------\n\n'examples/hello_world.c' contains a small \"Hello World\" Demo\napplication; it is automatically compiled when you build U-Boot.\nIt's configured to run at address 0x00040004, so you can play with it\nlike that:\n\n\t=\u003e loads\n\t## Ready for S-Record download ...\n\t~\u003eexamples/hello_world.srec\n\t1 2 3 4 5 6 7 8 9 10 11 ...\n\t[file transfer complete]\n\t[connected]\n\t## Start Addr = 0x00040004\n\n\t=\u003e go 40004 Hello World! This is a test.\n\t## Starting application at 0x00040004 ...\n\tHello World\n\targc = 7\n\targv[0] = \"40004\"\n\targv[1] = \"Hello\"\n\targv[2] = \"World!\"\n\targv[3] = \"This\"\n\targv[4] = \"is\"\n\targv[5] = \"a\"\n\targv[6] = \"test.\"\n\targv[7] = \"\u003cNULL\u003e\"\n\tHit any key to exit ...\n\n\t## Application terminated, rc = 0x0\n\nAnother example, which demonstrates how to register a CPM interrupt\nhandler with the U-Boot code, can be found in 'examples/timer.c'.\nHere, a CPM timer is set up to generate an interrupt every second.\nThe interrupt service routine is trivial, just printing a '.'\ncharacter, but this is just a demo program. The application can be\ncontrolled by the following keys:\n\n\t? - print current values og the CPM Timer registers\n\tb - enable interrupts and start timer\n\te - stop timer and disable interrupts\n\tq - quit application\n\n\t=\u003e loads\n\t## Ready for S-Record download ...\n\t~\u003eexamples/timer.srec\n\t1 2 3 4 5 6 7 8 9 10 11 ...\n\t[file transfer complete]\n\t[connected]\n\t## Start Addr = 0x00040004\n\n\t=\u003e go 40004\n\t## Starting application at 0x00040004 ...\n\tTIMERS=0xfff00980\n\tUsing timer 1\n\t  tgcr @ 0xfff00980, tmr @ 0xfff00990, trr @ 0xfff00994, tcr @ 0xfff00998, tcn @ 0xfff0099c, ter @ 0xfff009b0\n\nHit 'b':\n\t[q, b, e, ?] Set interval 1000000 us\n\tEnabling timer\nHit '?':\n\t[q, b, e, ?] ........\n\ttgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0xef6, ter=0x0\nHit '?':\n\t[q, b, e, ?] .\n\ttgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x2ad4, ter=0x0\nHit '?':\n\t[q, b, e, ?] .\n\ttgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x1efc, ter=0x0\nHit '?':\n\t[q, b, e, ?] .\n\ttgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x169d, ter=0x0\nHit 'e':\n\t[q, b, e, ?] ...Stopping timer\nHit 'q':\n\t[q, b, e, ?] ## Application terminated, rc = 0x0\n\n\nMinicom warning:\n================\n\nOver time, many people have reported problems when trying to use the\n\"minicom\" terminal emulation program for serial download. I (wd)\nconsider minicom to be broken, and recommend not to use it. Under\nUnix, I recommend to use C-Kermit for general purpose use (and\nespecially for kermit binary protocol download (\"loadb\" command), and\nuse \"cu\" for S-Record download (\"loads\" command).  See\nhttps://www.denx.de/wiki/view/DULG/SystemSetup#Section_4.3.\nfor help with kermit.\n\n\nNevertheless, if you absolutely want to use it try adding this\nconfiguration to your \"File transfer protocols\" section:\n\n\t   Name\t   Program\t\t\tName U/D FullScr IO-Red. Multi\n\tX  kermit  /usr/bin/kermit -i -l %l -s\t Y    U\t   Y\t   N\t  N\n\tY  kermit  /usr/bin/kermit -i -l %l -r\t N    D\t   Y\t   N\t  N\n\n\nNetBSD Notes:\n=============\n\nStarting at version 0.9.2, U-Boot supports NetBSD both as host\n(build U-Boot) and target system (boots NetBSD/mpc8xx).\n\nBuilding requires a cross environment; it is known to work on\nNetBSD/i386 with the cross-powerpc-netbsd-1.3 package (you will also\nneed gmake since the Makefiles are not compatible with BSD make).\nNote that the cross-powerpc package does not install include files;\nattempting to build U-Boot will fail because \u003cmachine/ansi.h\u003e is\nmissing.  This file has to be installed and patched manually:\n\n\t# cd /usr/pkg/cross/powerpc-netbsd/include\n\t# mkdir powerpc\n\t# ln -s powerpc machine\n\t# cp /usr/src/sys/arch/powerpc/include/ansi.h powerpc/ansi.h\n\t# ${EDIT} powerpc/ansi.h\t## must remove __va_list, _BSD_VA_LIST\n\nNative builds *don't* work due to incompatibilities between native\nand U-Boot include files.\n\nBooting assumes that (the first part of) the image booted is a\nstage-2 loader which in turn loads and then invokes the kernel\nproper. Loader sources will eventually appear in the NetBSD source\ntree (probably in sys/arc/mpc8xx/stand/u-boot_stage2/); in the\nmeantime, see ftp://ftp.denx.de/pub/u-boot/ppcboot_stage2.tar.gz\n\n\nImplementation Internals:\n=========================\n\nThe following is not intended to be a complete description of every\nimplementation detail. However, it should help to understand the\ninner workings of U-Boot and make it easier to port it to custom\nhardware.\n\n\nInitial Stack, Global Data:\n---------------------------\n\nThe implementation of U-Boot is complicated by the fact that U-Boot\nstarts running out of ROM (flash memory), usually without access to\nsystem RAM (because the memory controller is not initialized yet).\nThis means that we don't have writable Data or BSS segments, and BSS\nis not initialized as zero. To be able to get a C environment working\nat all, we have to allocate at least a minimal stack. Implementation\noptions for this are defined and restricted by the CPU used: Some CPU\nmodels provide on-chip memory (like the IMMR area on MPC8xx and\nMPC826x processors), on others (parts of) the data cache can be\nlocked as (mis-) used as memory, etc.\n\n\tChris Hallinan posted a good summary of these issues to the\n\tU-Boot mailing list:\n\n\tSubject: RE: [U-Boot-Users] RE: More On Memory Bank x (nothingness)?\n\tFrom: \"Chris Hallinan\" \u003cclh@net1plus.com\u003e\n\tDate: Mon, 10 Feb 2003 16:43:46 -0500 (22:43 MET)\n\t...\n\n\tCorrect me if I'm wrong, folks, but the way I understand it\n\tis this: Using DCACHE as initial RAM for Stack, etc, does not\n\trequire any physical RAM backing up the cache. The cleverness\n\tis that the cache is being used as a temporary supply of\n\tnecessary storage before the SDRAM controller is setup. It's\n\tbeyond the scope of this list to explain the details, but you\n\tcan see how this works by studying the cache architecture and\n\toperation in the architecture and processor-specific manuals.\n\n\tOCM is On Chip Memory, which I believe the 405GP has 4K. It\n\tis another option for the system designer to use as an\n\tinitial stack/RAM area prior to SDRAM being available. Either\n\toption should work for you. Using CS 4 should be fine if your\n\tboard designers haven't used it for something that would\n\tcause you grief during the initial boot! It is frequently not\n\tused.\n\n\tCONFIG_SYS_INIT_RAM_ADDR should be somewhere that won't interfere\n\twith your processor/board/system design. The default value\n\tyou will find in any recent u-boot distribution in\n\twalnut.h should work for you. I'd set it to a value larger\n\tthan your SDRAM module. If you have a 64MB SDRAM module, set\n\tit above 400_0000. Just make sure your board has no resources\n\tthat are supposed to respond to that address! That code in\n\tstart.S has been around a while and should work as is when\n\tyou get the config right.\n\n\t-Chris Hallinan\n\tDS4.COM, Inc.\n\nIt is essential to remember this, since it has some impact on the C\ncode for the initialization procedures:\n\n* Initialized global data (data segment) is read-only. Do not attempt\n  to write it.\n\n* Do not use any uninitialized global data (or implicitly initialized\n  as zero data - BSS segment) at all - this is undefined, initiali-\n  zation is performed later (when relocating to RAM).\n\n* Stack space is very limited. Avoid big data buffers or things like\n  that.\n\nHaving only the stack as writable memory limits means we cannot use\nnormal global data to share information between the code. But it\nturned out that the implementation of U-Boot can be greatly\nsimplified by making a global data structure (gd_t) available to all\nfunctions. We could pass a pointer to this data as argument to _all_\nfunctions, but this would bloat the code. Instead we use a feature of\nthe GCC compiler (Global Register Variables) to share the data: we\nplace a pointer (gd) to the global data into a register which we\nreserve for this purpose.\n\nWhen choosing a register for such a purpose we are restricted by the\nrelevant  (E)ABI  specifications for the current architecture, and by\nGCC's implementation.\n\nFor PowerPC, the following registers have specific use:\n\tR1:\tstack pointer\n\tR2:\treserved for system use\n\tR3-R4:\tparameter passing and return values\n\tR5-R10: parameter passing\n\tR13:\tsmall data area pointer\n\tR30:\tGOT pointer\n\tR31:\tframe pointer\n\n\t(U-Boot also uses R12 as internal GOT pointer. r12\n\tis a volatile register so r12 needs to be reset when\n\tgoing back and forth between asm and C)\n\n    ==\u003e U-Boot will use R2 to hold a pointer to the global data\n\n    Note: on PPC, we could use a static initializer (since the\n    address of the global data structure is known at compile time),\n    but it turned out that reserving a register results in somewhat\n    smaller code - although the code savings are not that big (on\n    average for all boards 752 bytes for the whole U-Boot image,\n    624 text + 127 data).\n\nOn ARM, the following registers are used:\n\n\tR0:\tfunction argument word/integer result\n\tR1-R3:\tfunction argument word\n\tR9:\tplatform specific\n\tR10:\tstack limit (used only if stack checking is enabled)\n\tR11:\targument (frame) pointer\n\tR12:\ttemporary workspace\n\tR13:\tstack pointer\n\tR14:\tlink register\n\tR15:\tprogram counter\n\n    ==\u003e U-Boot will use R9 to hold a pointer to the global data\n\n    Note: on ARM, only R_ARM_RELATIVE relocations are supported.\n\nOn Nios II, the ABI is documented here:\n\thttps://www.altera.com/literature/hb/nios2/n2cpu_nii51016.pdf\n\n    ==\u003e U-Boot will use gp to hold a pointer to the global data\n\n    Note: on Nios II, we give \"-G0\" option to gcc and don't use gp\n    to access small data sections, so gp is free.\n\nOn NDS32, the following registers are used:\n\n\tR0-R1:\targument/return\n\tR2-R5:\targument\n\tR15:\ttemporary register for assembler\n\tR16:\ttrampoline register\n\tR28:\tframe pointer (FP)\n\tR29:\tglobal pointer (GP)\n\tR30:\tlink register (LP)\n\tR31:\tstack pointer (SP)\n\tPC:\tprogram counter (PC)\n\n    ==\u003e U-Boot will use R10 to hold a pointer to the global data\n\nNOTE: DECLARE_GLOBAL_DATA_PTR must be used with file-global scope,\nor current versions of GCC may \"optimize\" the code too much.\n\nOn RISC-V, the following registers are used:\n\n\tx0: hard-wired zero (zero)\n\tx1: return address (ra)\n\tx2:\tstack pointer (sp)\n\tx3:\tglobal pointer (gp)\n\tx4:\tthread pointer (tp)\n\tx5:\tlink register (t0)\n\tx8:\tframe pointer (fp)\n\tx10-x11:\targuments/return values (a0-1)\n\tx12-x17:\targuments (a2-7)\n\tx28-31:\t temporaries (t3-6)\n\tpc:\tprogram counter (pc)\n\n    ==\u003e U-Boot will use gp to hold a pointer to the global data\n\nMemory Management:\n------------------\n\nU-Boot runs in system state and uses physical addresses, i.e. the\nMMU is not used either for address mapping nor for memory protection.\n\nThe available memory is mapped to fixed addresses using the memory\ncontroller. In this process, a contiguous block is formed for each\nmemory type (Flash, SDRAM, SRAM), even when it consists of several\nphysical memory banks.\n\nU-Boot is installed in the first 128 kB of the first Flash bank (on\nTQM8xxL modules this is the range 0x40000000 ... 0x4001FFFF). After\nbooting and sizing and initializing DRAM, the code relocates itself\nto the upper end of DRAM. Immediately below the U-Boot code some\nmemory is reserved for use by malloc() [see CONFIG_SYS_MALLOC_LEN\nconfiguration setting]. Below that, a structure with global Board\nInfo data is placed, followed by the stack (growing downward).\n\nAdditionally, some exception handler code is copied to the low 8 kB\nof DRAM (0x00000000 ... 0x00001FFF).\n\nSo a typical memory configuration with 16 MB of DRAM could look like\nthis:\n\n\t0x0000 0000\tException Vector code\n\t      :\n\t0x0000 1FFF\n\t0x0000 2000\tFree for Application Use\n\t      :\n\t      :\n\n\t      :\n\t      :\n\t0x00FB FF20\tMonitor Stack (Growing downward)\n\t0x00FB FFAC\tBoard Info Data and permanent copy of global data\n\t0x00FC 0000\tMalloc Arena\n\t      :\n\t0x00FD FFFF\n\t0x00FE 0000\tRAM Copy of Monitor Code\n\t...\t\teventually: LCD or video framebuffer\n\t...\t\teventually: pRAM (Protected RAM - unchanged by reset)\n\t0x00FF FFFF\t[End of RAM]\n\n\nSystem Initialization:\n----------------------\n\nIn the reset configuration, U-Boot starts at the reset entry point\n(on most PowerPC systems at address 0x00000100). Because of the reset\nconfiguration for CS0# this is a mirror of the on board Flash memory.\nTo be able to re-map memory U-Boot then jumps to its link address.\nTo be able to implement the initialization code in C, a (small!)\ninitial stack is set up in the internal Dual Ported RAM (in case CPUs\nwhich provide such a feature like), or in a locked part of the data\ncache. After that, U-Boot initializes the CPU core, the caches and\nthe SIU.\n\nNext, all (potentially) available memory banks are mapped using a\npreliminary mapping. For example, we put them on 512 MB boundaries\n(multiples of 0x20000000: SDRAM on 0x00000000 and 0x20000000, Flash\non 0x40000000 and 0x60000000, SRAM on 0x80000000). Then UPM A is\nprogrammed for SDRAM access. Using the temporary configuration, a\nsimple memory test is run that determines the size of the SDRAM\nbanks.\n\nWhen there is more than one SDRAM bank, and the banks are of\ndifferent size, the largest is mapped first. For equal size, the first\nbank (CS2#) is mapped first. The first mapping is always for address\n0x00000000, with any additional banks following immediately to create\ncontiguous memory starting from 0.\n\nThen, the monitor installs itself at the upper end of the SDRAM area\nand allocates memory for use by malloc() and for the global Board\nInfo data; also, the exception vector code is copied to the low RAM\npages, and the final stack is set up.\n\nOnly after this relocation will you have a \"normal\" C environment;\nuntil that you are restricted in several ways, mostly because you are\nrunning from ROM, and because the code will have to be relocated to a\nnew address in RAM.\n\n\nU-Boot Porting Guide:\n----------------------\n\n[Based on messages by Jerry Van Baren in the U-Boot-Users mailing\nlist, October 2002]\n\n\nint main(int argc, char *argv[])\n{\n\tsighandler_t no_more_time;\n\n\tsignal(SIGALRM, no_more_time);\n\talarm(PROJECT_DEADLINE - toSec (3 * WEEK));\n\n\tif (available_money \u003e available_manpower) {\n\t\tPay consultant to port U-Boot;\n\t\treturn 0;\n\t}\n\n\tDownload latest U-Boot source;\n\n\tSubscribe to u-boot mailing list;\n\n\tif (clueless)\n\t\temail(\"Hi, I am new to U-Boot, how do I get started?\");\n\n\twhile (learning) {\n\t\tRead the README file in the top level directory;\n\t\tRead https://www.denx.de/wiki/bin/view/DULG/Manual;\n\t\tRead applicable doc/README.*;\n\t\tRead the source, Luke;\n\t\t/* find . -name \"*.[chS]\" | xargs grep -i \u003ckeyword\u003e */\n\t}\n\n\tif (available_money \u003e toLocalCurrency ($2500))\n\t\tBuy a BDI3000;\n\telse\n\t\tAdd a lot of aggravation and time;\n\n\tif (a similar board exists) {\t/* hopefully... */\n\t\tcp -a board/\u003csimilar\u003e board/\u003cmyboard\u003e\n\t\tcp include/configs/\u003csimilar\u003e.h include/configs/\u003cmyboard\u003e.h\n\t} else {\n\t\tCreate your own board support subdirectory;\n\t\tCreate your own board include/configs/\u003cmyboard\u003e.h file;\n\t}\n\tEdit new board/\u003cmyboard\u003e files\n\tEdit new include/configs/\u003cmyboard\u003e.h\n\n\twhile (!accepted) {\n\t\twhile (!running) {\n\t\t\tdo {\n\t\t\t\tAdd / modify source code;\n\t\t\t} until (compiles);\n\t\t\tDebug;\n\t\t\tif (clueless)\n\t\t\t\temail(\"Hi, I am having problems...\");\n\t\t}\n\t\tSend patch file to the U-Boot email list;\n\t\tif (reasonable critiques)\n\t\t\tIncorporate improvements from email list code review;\n\t\telse\n\t\t\tDefend code as written;\n\t}\n\n\treturn 0;\n}\n\nvoid no_more_time (int sig)\n{\n      hire_a_guru();\n}\n\n\nCoding Standards:\n-----------------\n\nAll contributions to U-Boot should conform to the Linux kernel\ncoding style; see the kernel coding style guide at\nhttps://www.kernel.org/doc/html/latest/process/coding-style.html, and the\nscript \"scripts/Lindent\" in your Linux kernel source directory.\n\nSource files originating from a different project (for example the\nMTD subsystem) are generally exempt from these guidelines and are not\nreformatted to ease subsequent migration to newer versions of those\nsources.\n\nPlease note that U-Boot is implemented in C (and to some small parts in\nAssembler); no C++ is used, so please do not use C++ style comments (//)\nin your code.\n\nPlease also stick to the following formatting rules:\n- remove any trailing white space\n- use TAB characters for indentation and vertical alignment, not spaces\n- make sure NOT to use DOS '\\r\\n' line feeds\n- do not add more than 2 consecutive empty lines to source files\n- do not add trailing empty lines to source files\n\nSubmissions which do not conform to the standards may be returned\nwith a request to reformat the changes.\n\n\nSubmitting Patches:\n-------------------\n\nSince the number of patches for U-Boot is growing, we need to\nestablish some rules. Submissions which do not conform to these rules\nmay be rejected, even when they contain important and valuable stuff.\n\nPlease see https://www.denx.de/wiki/U-Boot/Patches for details.\n\nPatches shall be sent to the u-boot mailing list \u003cu-boot@lists.denx.de\u003e;\nsee https://lists.denx.de/listinfo/u-boot\n\nWhen you send a patch, please include the following information with\nit:\n\n* For bug fixes: a description of the bug and how your patch fixes\n  this bug. Please try to include a way of demonstrating that the\n  patch actually fixes something.\n\n* For new features: a description of the feature and your\n  implementation.\n\n* For major contributions, add a MAINTAINERS file with your\n  information and associated file and directory references.\n\n* When you add support for a new board, don't forget to add a\n  maintainer e-mail address to the boards.cfg file, too.\n\n* If your patch adds new configuration options, don't forget to\n  document these in the README file.\n\n* The patch itself. If you are using git (which is *strongly*\n  recommended) you can easily generate the patch using the\n  \"git format-patch\". If you then use \"git send-email\" to send it to\n  the U-Boot mailing list, you will avoid most of the common problems\n  with some other mail clients.\n\n  If you cannot use git, use \"diff -purN OLD NEW\". If your version of\n  diff does not support these options, then get the latest version of\n  GNU diff.\n\n  The current directory when running this command shall be the parent\n  directory of the U-Boot source tree (i. e. please make sure that\n  your patch includes sufficient directory information for the\n  affected files).\n\n  We prefer patches as plain text. MIME attachments are discouraged,\n  and compressed attachments must not be used.\n\n* If one logical set of modifications affects or creates several\n  files, all these changes shall be submitted in a SINGLE patch file.\n\n* Changesets that contain different, unrelated modifications shall be\n  submitted as SEPARATE patches, one patch per changeset.\n\n\nNotes:\n\n* Before sending the patch, run the buildman script on your patched\n  source tree and make sure that no errors or warnings are reported\n  for any of the boards.\n\n* Keep your modifications to the necessary minimum: A patch\n  containing several unrelated changes or arbitrary reformats will be\n  returned with a request to re-formatting / split it.\n\n* If you modify existing code, make sure that your new code does not\n  add to the memory footprint of the code ;-) Small is beautiful!\n  When adding new features, these should compile conditionally only\n  (using #ifdef), and the resulting code with the new feature\n  disabled must not need more memory than the old code without your\n  modification.\n\n* Remember that there is a size limit of 100 kB per message on the\n  u-boot mailing list. Bigger patches will be moderated. If they are\n  reasonable and not too big, they will be acknowledged. But patches\n  bigger than the size limit should be avoided.\n","funding_links":[],"categories":[],"sub_categories":[],"project_url":"https://awesome.ecosyste.ms/api/v1/projects/github.com%2Funframework%2Fu-boot","html_url":"https://awesome.ecosyste.ms/projects/github.com%2Funframework%2Fu-boot","lists_url":"https://awesome.ecosyste.ms/api/v1/projects/github.com%2Funframework%2Fu-boot/lists"}