[PATCH] efi_loader: efi_var_sf: Do not fail on blank SPI Flash

[Michal Simek]

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 at amd.com>
Signed-off-by: Michal Simek <michal.simek at amd.com>
---

 lib/efi_loader/efi_var_sf.c | 9 ++++++---
 1 file changed, 6 insertions(+), 3 deletions(-)

diff --git a/lib/efi_loader/efi_var_sf.c b/lib/efi_loader/efi_var_sf.c
index 6eae8d464645..a1dc81e17434 100644
--- a/lib/efi_loader/efi_var_sf.c
+++ b/lib/efi_loader/efi_var_sf.c
@@ -98,12 +98,15 @@ efi_status_t efi_var_from_storage(void)
 		goto error;
 	}
 
-	if (efi_var_restore(buf, false) != EFI_SUCCESS) {
-		log_err("No valid EFI variables in SPI Flash\n");
-		ret = EFI_DEVICE_ERROR;
+	if (buf->magic != EFI_VAR_FILE_MAGIC) {
+		log_info("No EFI variables in SPI Flash\n");
+		ret = EFI_SUCCESS;
 		goto error;
 	}
 
+	if (efi_var_restore(buf, false) != EFI_SUCCESS)
+		log_err("Invalid EFI variables in SPI Flash\n");
+
 	ret = EFI_SUCCESS;
 error:
 	free(buf);
-- 
2.43.0

base-commit: 85854708c4d707d9db8ec84c11e1686a32198d91
branch: debian-sent3