Add support for using a sysfail boot entry in case of UEFI firmware
capsule update failure [1]. The status of a firmware update is obtained from
the EFI System Resource Table (ESRT), which provides an optional mechanism
for identifying device and system firmware resources for the purposes of
targeting firmware updates to those resources.
Current implementation uses the value of LastAttemptStatus field from
ESRT, which describes the result of the last firmware update attempt for
the firmware resource entry. The field is updated each time an
UpdateCapsule() is attempted for an ESRT entry and is preserved across
reboots (non-volatile).
This can be be used in setups with support for A/B OTA updates, where
the boot firmware and Linux/RootFS might be updated synchronously.
[1] https://uefi.org/specs/UEFI/2.10/23_Firmware_Update_and_Reporting.html
Signed-off-by: Igor Opaniuk <igor.opaniuk@foundries.io>
Add support for a sysfail boot entry. Sysfail boot entries can be
used for optional tweaking the automatic selection order in case a
failure state of the system in some form is detected (boot firmware
failure etc).
The EFI variable `LoaderEntrySysFail` holds the boot loader entry to
be used in the event of a system failure. If a failure occurs, the reason
will be stored in the `LoaderSysFailReason` EFI variable.
sysfail_check() expected to be extented to support possible
conditions when we should boot sysfail("recovery") boot entry.
Signed-off-by: Igor Opaniuk <igor.opaniuk@foundries.io>