Data

Tools

Indexes

Applications

Experiments

Awesome

An open API service indexing awesome lists of open source software.

https://github.com/openbmc/phosphor-ipmi-flash

OpenBMC IPMI Library (Handler) for In-Band Firmware Update
https://github.com/openbmc/phosphor-ipmi-flash

Last synced: 10 months ago
JSON representation

OpenBMC IPMI Library (Handler) for In-Band Firmware Update

Awesome Lists containing this project

README 

          
# Secure Flash Update Mechanism



This document describes the OpenBmc software implementing the secure flash

update mechanism.



The primary details are in

[OpenBMC docs](https://github.com/openbmc/docs/blob/master/designs/firmware-update-via-blobs.md).



## Building and using the host-tool



This repo contains a host-tool implementation for talking to the corresponding

BMC blob handler.



### Building the host-tool



The host-tool depends on ipmi-blob-tool and pciutils.



#### Building libpciaccess



Check out the

[xorg-macros source](https://gitlab.freedesktop.org/xorg/util/macros).



Then run these commands in the source directory.



```sh

./autogen.sh --prefix=/usr

make install

```



Check out the

[libpciaccess source](https://gitlab.freedesktop.org/xorg/lib/libpciaccess).



Then run these commands in the source directory.



```sh

./autogen.sh

make

make install

```



#### Building ipmi-blob-tool



Check out the

[ipmi-blob-tool source](https://github.com/openbmc/ipmi-blob-tool).



Then run these commands in the source directory.



```sh

./bootstrap.sh

./configure

make

make install

```



#### Building stdplus



Check out the [stdplus source](https://github.com/openbmc/stdplus).



Then run these commands in the source directory.



```sh

meson setup -Dexamples=false -Dtests=disabled builddir

ninja -C builddir

ninja -C builddir install

```



#### Building burn_my_bmc (the host-tool)



Check out the

[phosphor-ipmi-flash source](https://github.com/openbmc/phosphor-ipmi-flash).



Then run these commands in the source directory.



```sh

./bootstrap.sh

./configure --disable-build-bmc-blob-handler

make

make install

```



_NOTE:_ When building from the OpenBMC SDK your configuration call will be:



```sh

./configure --enable-oe-sdk --host "$(uname -m)" --disable-build-bmc-blob-handler AR=x86_64-openbmc-linux-gcc-ar RANLIB=x86_64-openbmc-linux-gcc-ranlib

```



### Parameters



The host-tool has parameters that let the caller specify every required detail.



The required parameters are:



| Parameter   | Options                                                                  | Meaning                                                                                                                                  |

| ----------- | ------------------------------------------------------------------------ | ---------------------------------------------------------------------------------------------------------------------------------------- |

| `command`   | `update`                                                                 | The tool should try to update the BMC firmware.                                                                                          |

| `interface` | `ipmibt`, `ipmilpc`, `ipmipci`, `ipminet`, `ipmipci-skip-bridge-disable` | The data transport mechanism, typically `ipmilpc`. The `ipmipci-skip-bridge-disable` is `ipmipci` but does not disable the bridge after. |

| `image`     | path                                                                     | The BMC firmware image file (or tarball)                                                                                                 |

| `sig`       | path                                                                     | The path to a signature file to send to the BMC along with the image file.                                                               |

| `type`      | blob ending                                                              | The ending of the blob id. For instance `/flash/image` becomes a type of `image`.                                                        |



If you're using an LPC data transfer mechanism, you'll need two additional

parameters: `address` and `length`. These values indicate where on the host

you've reserved memory to be used for the transfer window.



If you're using a net data transfer mechanism, you'll also need two additional

parameters: `hostname` and `port`. These specify which address and port the tool

should attempt to connect to the BMC using. If unspecified, the `port` option

defaults to 623, the same port as IPMI LAN+.



## Introduction



This supports three methods of providing the image to stage. You can send the

file over IPMI packets, which is a very slow process. A 32-MiB image can take ~3

hours to send via this method. This can be done in <1 minutes via the PCI or net

bridge, or just a few minutes via LPC depending on the size of the mapped area.



This is implemented as a phosphor blob handler.



The image must be signed via the production or development keys, the former

being required for production builds. The image itself and the image signature

are separately sent to the BMC for verification. The verification package source

is beyond the scope of this design.



Basically the IPMI OEM handler receives the image in one fashion or another and

then triggers the `verify_image` service. Then, the user polls until the result

is reported. This is because the image verification process can exceed 10

seconds.



### Using Legacy Images



The image flashing mechanism itself is the initramfs stage during reboot. It

will check for files named "`image-*`" and flash them appropriately for each

name to section. The IPMI command creates a file `/run/initramfs/bmc-image` and

writes the contents there. It was found that writing it in /tmp could cause OOM

errors moving it on low memory systems, whereas renaming a file within the same

folder seems to only update the directory inode's contents.



### Using UBI



The staging file path can be controlled via software configuration. The image is

assumed to be the tarball contents and is written into `/tmp/{tarball_name}.gz`



TODO: Flesh out the UBI approach.



## Configuration



To use `phosphor-ipmi-flash` a platform must provide a configuration. A platform

can configure multiple interfaces, such as both lpc and pci. However, a platform

should only configure either static layout updates, or ubi. If enabling lpc, the

platform must specify either aspeed or nuvoton. The system also supports

receiving BIOS updates.



The following are the two primary configuration options, which control how the

update is treated.



| Option                   | Meaning                                                 |

| ------------------------ | ------------------------------------------------------- |

| `--enable-static-layout` | Enable treating the update as a static layout update.   |

| `--enable-tarball-ubi`   | Enable treating the update as a tarball for UBI update. |

| `--enable-host-bios`     | Enable receiving the update for a host bios update.     |



The following are configuration options for how the host and BMC are meant to

transfer the data. By default, the data-in-IPMI mechanism is enabled.



There are three configurable data transport mechanisms, either staging the bytes

via the LPC memory region, the PCI-to-AHB memory region, or sending over a

network connection. Because there is only one `MAPPED_ADDRESS` variable at

present, a platform should not configure LPC and P2A at the same time. The

platform's device-tree may have the region locked to a specific driver

(lpc-aspeed-ctrl), preventing the region from other use.



**_NOTE:_** It will likely be possible to configure both LPC and P2A in the near

future.



| Variable         | Default | Meaning                                                              |

| ---------------- | ------- | -------------------------------------------------------------------- |

| `MAPPED_ADDRESS` | 0       | The address used for mapping P2A or LPC into the BMC's memory-space. |



There are two kinds of PCI device-id for NPCM7xx and NPCM8xx respectively. For

NPCM7xx the device-id is using 0x0750 and NPCM8xx is using 0x0850. Use this

variable that can help to build host tool burn_my_bmc compatible with different

platforms and make in-band firmware update work well.



| Variable          | Default | Meaning                               |

| ----------------- | ------- | ------------------------------------- |

| `NUVOTON_PCI_DID` | 0x0750  | The device-id for Nuvoton PCI bridge. |



If a platform enables p2a as the transport mechanism, a specific vendor must be

selected via the following configuration option. Currently, only one is

supported.



| Option                | Meaning                |

| --------------------- | ---------------------- |

| `--enable-aspeed-p2a` | Use with ASPEED parts. |



If a platform enables lpc as the transport mechanism, a specific vendor must be

selected via the following configuration option. Currently, only two are

supported.



| Option                 | Meaning                 |

| ---------------------- | ----------------------- |

| `--enable-aspeed-lpc`  | Use with ASPEED parts.  |

| `--enable-nuvoton-lpc` | Use with Nuvoton parts. |



A platform may also enable the network transport mechanism.



NOTE: This mechanism is only intended to be used in-band and not exposed

externally, as it doesn't implement any encryption or integrity verification.



| Option                | Meaning                     |

| --------------------- | --------------------------- |

| `--enable-net-bridge` | Enable net transport bridge |



There are also options to control an optional clean up mechanism.



| Option                    | Meaning                                          |

| ------------------------- | ------------------------------------------------ |

| `--enable-cleanup-delete` | Provide a simple blob id that deletes artifacts. |



If the update mechanism desired is simply a BMC reboot, a platform can just

enable that directly.



| Option                   | Meaning                                |

| ------------------------ | -------------------------------------- |

| `--enable-reboot-update` | Enable use of reboot update mechanism. |



If you would like the update status to be tracked with a status file, this

option can be enabled. Note that `--enable-update-status` option and the above

`--enable-reboot-update` option cannot be enabled at the same time.



| Option                   | Meaning                           |

| ------------------------ | --------------------------------- |

| `--enable-update-status` | Enable use of update status file. |



If you would like to use host memory access to update on a PPC platform, this

configuration option needs to be enabled.



| Option         | Meaning                        |

| -------------- | ------------------------------ |

| `--enable-ppc` | Enable PPC host memory access. |



### Internal Configuration Details



The following variables can be set to whatever you wish, however they have

usable default values.



| Variable                      | Default                                   | Meaning                                                                   |

| ----------------------------- | ----------------------------------------- | ------------------------------------------------------------------------- |

| `STATIC_HANDLER_STAGED_NAME`  | `/run/initramfs/bmc-image`                | The filename where to write the staged firmware image for static updates. |

| `TARBALL_STAGED_NAME`         | `/tmp/image-update.tar`                   | The filename where to write the UBI update tarball.                       |

| `HASH_FILENAME`               | `/tmp/bmc.sig`                            | The file to use for the hash provided.                                    |

| `PREPARATION_DBUS_SERVICE`    | `phosphor-ipmi-flash-bmc-prepare.target`  | The systemd target started when the host starts to send an update.        |

| `VERIFY_STATUS_FILENAME`      | `/tmp/bmc.verify`                         | The file checked for the verification status.                             |

| `VERIFY_DBUS_SERVICE`         | `phosphor-ipmi-flash-bmc-verify.target`   | The systemd target started for verification.                              |

| `UPDATE_DBUS_SERVICE`         | `phosphor-ipmi-flash-bmc-update.target`   | The systemd target started for updating the BMC.                          |

| `UPDATE_STATUS_FILENAME`      | `/tmp/bmc.update`                         | The file checked for the update status.                                   |

| `BIOS_STAGED_NAME`            | `/tmp/bios-image`                         | The file to use for staging the bios firmware update.                     |

| `BIOS_VERIFY_STATUS_FILENAME` | `/tmp/bios.verify`                        | The file checked for the verification status.                             |

| `PREPARATION_BIOS_TARGET`     | `phosphor-ipmi-flash-bios-prepare.target` | The systemd target when the host starts to send an update.                |

| `VERIFY_BIOS_TARGET`          | `phosphor-ipmi-flash-bios-verify.target`  | The systemd target started for verification.                              |

| `UPDATE_BIOS_TARGET`          | `phosphor-ipmi-flash-bios-update.target`  | The systemd target started for updating the BIOS.                         |



## JSON Configuration



Read the [details](bmc_json_config.md) of the json configuration. The json

configurations are used to configure the BMC's flash handler behaviors.



## Flash State Machine Details



[This document](ipmi_flash.md) describes the details of the state machine

implemented and how different interactions with it will respond. This also

describes how a host-side tool is expected to talk to it (triggering different

states and actions).