{"id":47014826,"url":"https://github.com/linux4sam/dt-overlay-at91","last_synced_at":"2026-03-11T21:46:20.551Z","repository":{"id":50906870,"uuid":"149254069","full_name":"linux4sam/dt-overlay-at91","owner":"linux4sam","description":"AT91 Device Tree Overlays and FIT image descriptors","archived":false,"fork":false,"pushed_at":"2025-11-13T09:51:45.000Z","size":649,"stargazers_count":12,"open_issues_count":1,"forks_count":34,"subscribers_count":23,"default_branch":"master","last_synced_at":"2025-11-13T11:27:38.624Z","etag":null,"topics":["devicetree","microchip","u-boot"],"latest_commit_sha":null,"homepage":null,"language":"Shell","has_issues":true,"has_wiki":null,"has_pages":null,"mirror_url":null,"source_name":null,"license":"other","status":null,"scm":"git","pull_requests_enabled":true,"icon_url":"https://github.com/linux4sam.png","metadata":{"files":{"readme":"README.md","changelog":null,"contributing":null,"funding":null,"license":"COPYING","code_of_conduct":null,"threat_model":null,"audit":null,"citation":null,"codeowners":null,"security":null,"support":null,"governance":null,"roadmap":null,"authors":null,"dei":null,"publiccode":null,"codemeta":null,"zenodo":null,"notice":null,"maintainers":null,"copyright":null,"agents":null,"dco":null,"cla":null}},"created_at":"2018-09-18T08:27:11.000Z","updated_at":"2025-11-13T09:51:30.000Z","dependencies_parsed_at":"2024-04-01T15:30:33.732Z","dependency_job_id":"6a100022-8f80-41da-9687-528d29db9fb3","html_url":"https://github.com/linux4sam/dt-overlay-at91","commit_stats":null,"previous_names":[],"tags_count":66,"template":false,"template_full_name":null,"purl":"pkg:github/linux4sam/dt-overlay-at91","repository_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/repositories/linux4sam%2Fdt-overlay-at91","tags_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/repositories/linux4sam%2Fdt-overlay-at91/tags","releases_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/repositories/linux4sam%2Fdt-overlay-at91/releases","manifests_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/repositories/linux4sam%2Fdt-overlay-at91/manifests","owner_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/owners/linux4sam","download_url":"https://codeload.github.com/linux4sam/dt-overlay-at91/tar.gz/refs/heads/master","sbom_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/repositories/linux4sam%2Fdt-overlay-at91/sbom","scorecard":null,"host":{"name":"GitHub","url":"https://github.com","kind":"github","repositories_count":286080680,"owners_count":30402330,"icon_url":"https://github.com/github.png","version":null,"created_at":"2022-05-30T11:31:42.601Z","updated_at":"2026-03-11T21:02:20.017Z","status":"ssl_error","status_checked_at":"2026-03-11T20:59:32.667Z","response_time":84,"last_error":"SSL_connect returned=1 errno=0 peeraddr=140.82.121.5:443 state=error: unexpected eof while reading","robots_txt_status":"success","robots_txt_updated_at":"2025-07-24T06:49:26.215Z","robots_txt_url":"https://github.com/robots.txt","online":false,"can_crawl_api":true,"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":["devicetree","microchip","u-boot"],"created_at":"2026-03-11T21:46:20.320Z","updated_at":"2026-03-11T21:46:20.544Z","avatar_url":"https://github.com/linux4sam.png","language":"Shell","funding_links":[],"categories":[],"sub_categories":[],"readme":"# Microchip Device Tree Overlays and FIT image\n\n## 1. Introduction\n\nA device tree overlay is a file that can be used at runtime (by the bootloader \nin our case) to dynamically modify the device tree, by adding nodes to the tree \nand making changes to properties in the existing tree.\n\nThe FIT (Flattened Image Tree) format allows for flexibility in handling images \nof various types and enhances integrity protection of images with stronger checksums.\n\n## 2. Build DT-Overlay\n\nTo build the overlays for a board make sure the following steps are done:\n\n* the environment variables ARCH and CROSS_COMPILE are set correctly. By default,\nARCH is set to arm and will need to be explicitly overridden for riscv.\n* (optional) the environment variable KERNEL_DIR points to Linux kernel and the \nkernel was already built for the board. This is needed because the DT Overlay \nrepository uses the Device Tree Compiler (dtc) from the kernel source tree. By default, \nKERNEL_DIR is set to a linux directory that would be under the parent directory \nin the directory tree: ../linux\n* (optional) the environment variable KERNEL_BUILD_DIR that points to where the Linux \nkernel binary and Device Tree blob, resulting of your compilation of the kernel, are \nlocated. By default, KERNEL_BUILD_DIR is set to the same directory as KERNEL_DIR. It \nshouldn't be changed if you have the habit of compiling your kernel within the Linux \nsource tree \n\nThe following example shows how to build the overlays for sama5d2_xplained:\n\n    $ make sama5d2_xplained_dtbos\n\n## 3. Build FIT image\n\n To build the FIT image with overlays for a board make sure the following steps \nare done:\n\n* the environment variables ARCH and CROSS_COMPILE are set correctly. By default,\nARCH is set to arm and will need to be explicitly overridden for riscv.\n* (optional) the environment variable KERNEL_DIR points to Linux kernel and the \nkernel was already built for the board. This is needed because the DT Overlay \nrepository uses the Device Tree Compiler (dtc) from the kernel source tree. By \ndefault, KERNEL_DIR is set to a linux directory that would be under the parent \ndirectory in the directory tree: ../linux\n* (optional) the environment variable KERNEL_BUILD_DIR that points to where the \nLinux kernel binary and Device Tree blob, resulting of your compilation of the \nkernel, are located. By default, KERNEL_BUILD_DIR is set to the same directory \nas KERNEL_DIR. It shouldn't be changed if you have the habit of compiling your \nkernel within the Linux source tree.\n* mkimage is installed on the development machine and the Device Tree Compiler \nfrom Linux kernel is in the PATH environment variable \n\nThe following example shows how to build the FIT image for sama5d2_xplained:\n\n    $ make sama5d2_xplained.itb\n\n## 4. Loading FIT image in u-boot\n\nThe FIT image is a placeholder that has the zImage and the base Device Tree, plus \nadditional overlays that can be selected at boot time.\n\nThe following steps are required to boot the FIT Image from U-boot:\n\n* Load the FIT image like you would normally load the uImage or zImage.\n* There is no need to load additional Device Tree Blob, the FIT image includes it\n* When booting the FIT image, specify the FIT configuration to use. Several \nconfigurations can be appended to the basic configuration, which we name 'kernel_dtb' \n\nExample:\n\n    bootm 0x24000000#kernel_dtb\n\nThis will load the FIT image from address 0x24000000 in memory and then run the \nconfiguration named 'kernel_dtb'. This configuration includes the kernel plus the \nbase Device Tree Blob built with the kernel.\n\nTo load additional FIT configurations, just append another configuration to the command.\n\nExample to load the image sensor controller Device Tree overlay + sensor omnivision 0v7740:\n\n    bootm 0x24000000#kernel_dtb#isc#ov7740\n\n## 5. Contributing\n\nTo contribute to Microchip Device Tree Overlays, you should submit patches for \nreview to the github pull-request facility directly. Do not forget to Cc the \nmaintainers.\n\nMaintainers:\n\nCristian Birsan \u003ccristian.birsan@microchip.com\u003e\n\nNicolas Ferre \u003cnicolas.ferre@microchip.com\u003e\n\nFor PolarFire SoC (MPFS), please also Cc:\n\nValentina Fernandez Alanis \u003cvalentina.fernandezalanis@microchip.com\u003e\n\nWhen creating patches insert the [dt-overlay-mchp] tag in the subject, for example\nuse something like:\n\n    git format-patch -s --subject-prefix='dt-overlay-mchp][PATCH' \u003corigin\u003e\n","project_url":"https://awesome.ecosyste.ms/api/v1/projects/github.com%2Flinux4sam%2Fdt-overlay-at91","html_url":"https://awesome.ecosyste.ms/projects/github.com%2Flinux4sam%2Fdt-overlay-at91","lists_url":"https://awesome.ecosyste.ms/api/v1/projects/github.com%2Flinux4sam%2Fdt-overlay-at91/lists"}