efi_loader: discover if no efi_system_partition is set

Variable efi_system_partition holds the efi_system_partition. Currently it
is initialized as:

    {
      .uclass_id = 0 = UCLASS_ROOT,
      .denum = 0,
      .part = 0,
    }

This indicates that host 0:0 is the efi_system_partition and we see output
like:

    => bootefi hello
    ** Bad device specification host 0 **
    Couldn't find partition host 0:0

To identify that no EFI system partition has been set use UCLASS_INVALID.

Signed-off-by: Heinrich Schuchardt <heinrich.schuchardt@canonical.com>
Reviewed-by: Ilias Apalodimas <ilias.apalodimas@linaro.org>

diff --git a/lib/efi_loader/efi_disk.c b/lib/efi_loader/efi_disk.c
index f11722d..a50a46c 100644 (file)
--- a/lib/efi_loader/efi_disk.c
+++ b/lib/efi_loader/efi_disk.c
@@ -19,7 +19,9 @@
 #include <part.h>
 #include <malloc.h>
 
-struct efi_system_partition efi_system_partition;
+struct efi_system_partition efi_system_partition = {
+       .uclass_id = UCLASS_INVALID,
+};
 
 const efi_guid_t efi_block_io_guid = EFI_BLOCK_IO_PROTOCOL_GUID;
 const efi_guid_t efi_system_partition_guid = PARTITION_SYSTEM_GUID;
@@ -511,7 +513,7 @@ static efi_status_t efi_disk_add_dev(
                  diskobj->media.last_block);
 
        /* Store first EFI system partition */
-       if (part && !efi_system_partition.uclass_id) {
+       if (part && efi_system_partition.uclass_id == UCLASS_INVALID) {
                if (part_info->bootable & PART_EFI_SYSTEM_PARTITION) {
                        efi_system_partition.uclass_id = desc->uclass_id;
                        efi_system_partition.devnum = desc->devnum;