On Thu, Oct 29, 2020 at 01:47:40PM +0900, AKASHI Takahiro wrote:
Summary
'UpdateCapsule' is one of runtime services defined in UEFI specification and its aim is to allow a caller (OS) to pass information to the firmware, i.e. U-Boot. This is mostly used to update firmware binary on devices by instructions from OS.
While 'UpdateCapsule' is a runtime services function, it is, at least initially, supported only before exiting boot services alike other runtime functions, [Get/]SetVariable. This is because modifying storage which may be shared with OS must be carefully designed and there is no general assumption that we can do it.
Therefore, we practically support only "capsule on disk"; any capsule can be handed over to UEFI subsystem as a file on a specific file system.
In this patch series, all the related definitions and structures are given as UEFI specification describes, and basic framework for capsule support is provided. Currently supported is
- firmware update (Firmware Management Protocol or simply FMP)
Most of functionality of firmware update is provided by FMP driver and it can be, by nature, system/platform-specific. So you can and should implement your own FMP driver(s) based on your system requirements. Under the current implementation, we provide two basic but generic drivers with two formats:
- FIT image format (as used in TFTP update and dfu)
- raw image format
It's totally up to users which one, or both, should be used on users' system depending on user requirements.
Quick usage
- You can create a capsule file with the following host command:
$ mkeficapsule [--fit <fit image> | --raw <raw image>] <output file>
- Put the file under:
/EFI/UpdateCapsule of UEFI system partition
- Specify firmware storage to be updated in "dfu_alt_info" variable (Please follow README.dfu for details.)
==> env set dfu_alt_info '...'
- After setting up UEFI's OsIndications variable, reboot U-Boot:
OsIndications <= EFI_OS_INDICATIONS_FILE_CAPSULE_DELIVERY_SUPPORTED
Patch structure
Patch#1-#4,#12: preparatory patches Patch#5-#11,#13: main part of implementation Patch#14-#15: utilities Patch#16-#17: pytests
[1] https://git.linaro.org/people/takahiro.akashi/u-boot.git efi/capsule
Prerequisite patches
None
Test
- passed all the pytests which are included in this patch series on sandbox build locally.
Please note that the capsule pytest itself won't be run in the CI partly because some specific configuration for sandbox build is required and partly because there is a problem with virt-make-fs. See test_efi_capsule_firmware.py.
Maybe we need to talk about this differently then. Today, the tests start on CI and then fail to run. That's a problem that needs to be fixed, they must "skip" properly. I would really like to see these tests run with every CI loop. That means doing a "try virt-make-fs, if that fails, try sudo, if that fails, skip". That also means updating some other tests that have logic for virt-make-fs, but it then causes CI to fail rather than try sudo.
What I see as the worst case is that we have tests for this feature that are only ever run when someone runs them intentionally, and CI skips them all the time.