When SPI Flash is blank (first boot or erased), efi_var_from_storage()
returns EFI_DEVICE_ERROR because efi_var_restore() fails on invalid
magic/CRC. This prevents the EFI subsystem from initializing.
Check the magic value before attempting to restore variables. If
the magic does not match EFI_VAR_FILE_MAGIC, treat it as an empty
store and return EFI_SUCCESS, matching the behavior of the file-based
efi_var_file.c which deliberately returns EFI_SUCCESS on missing or
corrupted variable files to avoid blocking the boot process.
Similarly, if the magic matches but efi_var_restore() fails (e.g.
corrupted CRC), log the error but still return EFI_SUCCESS.
Suggested-by: John Toomey <john.toomey@amd.com>
Signed-off-by: Michal Simek <michal.simek@amd.com>
Reviewed-by: Ilias Apalodimas <ilias.apalodimas@linaro.org>
Reviewed-by: Heinrich Schuchardt <heinrich.schuchardt@canonical.com>
57eae396ec