efi_loader: improve efi_var_from_file() description

It is unclear to developers why efi_var_from_file() returns EFI_SUCCESS if
file ubootefi.var is missing or corrupted. Improve the description.

Reported-by: Weizhao Ouyang <o451686892@gmail.com>
Signed-off-by: Heinrich Schuchardt <heinrich.schuchardt@canonical.com>
Reviewed-by: Weizhao Ouyang <o451686892@gmail.com>

diff --git a/lib/efi_loader/efi_var_file.c b/lib/efi_loader/efi_var_file.c
index 62e071bd834111af1953dbd300252b23ff6d46e2..d7dba050710af1cb91b266cfe7df80a17f202f52 100644 (file)
--- a/lib/efi_loader/efi_var_file.c
+++ b/lib/efi_loader/efi_var_file.c
@@ -204,8 +204,11 @@ efi_status_t efi_var_restore(struct efi_var_file *buf, bool safe)
  * File ubootefi.var is read from the EFI system partitions and the variables
  * stored in the file are created.
  *
- * In case the file does not exist yet or a variable cannot be set EFI_SUCCESS
- * is returned.
+ * On first boot the file ubootefi.var does not exist yet. This is why we must
+ * return EFI_SUCCESS in this case.
+ *
+ * If the variable file is corrupted, e.g. incorrect CRC32, we do not want to
+ * stop the boot process. We deliberately return EFI_SUCCESS in this case, too.
  *
  * Return:     status code
  */