part: extract MBR signature from partitions
EFI client programs need the signature information from the partition
table to determine the disk a partition is on, so we need to fill that
in here.
Signed-off-by: Peter Jones <pjones@redhat.com>
[separated from efi_loader part, and fixed build-errors for non-
CONFIG_EFI_PARTITION case]
Signed-off-by: Rob Clark <robdclark@gmail.com>
Signed-off-by: Alexander Graf <agraf@suse.de>
diff --git a/disk/part_efi.c b/disk/part_efi.c
index 2973d52..208bb14 100644
--- a/disk/part_efi.c
+++ b/disk/part_efi.c
@@ -923,11 +923,19 @@
static int is_gpt_valid(struct blk_desc *dev_desc, u64 lba,
gpt_header *pgpt_head, gpt_entry **pgpt_pte)
{
+ ALLOC_CACHE_ALIGN_BUFFER(legacy_mbr, mbr, dev_desc->blksz);
+
if (!dev_desc || !pgpt_head) {
printf("%s: Invalid Argument(s)\n", __func__);
return 0;
}
+ /* Read MBR Header from device */
+ if (blk_dread(dev_desc, 0, 1, (ulong *)mbr) != 1) {
+ printf("*** ERROR: Can't read MBR header ***\n");
+ return 0;
+ }
+
/* Read GPT Header from device */
if (blk_dread(dev_desc, (lbaint_t)lba, 1, pgpt_head) != 1) {
printf("*** ERROR: Can't read GPT header ***\n");
@@ -937,6 +945,18 @@
if (validate_gpt_header(pgpt_head, (lbaint_t)lba, dev_desc->lba))
return 0;
+ if (dev_desc->sig_type == SIG_TYPE_NONE) {
+ efi_guid_t empty = {};
+ if (memcmp(&pgpt_head->disk_guid, &empty, sizeof(empty))) {
+ dev_desc->sig_type = SIG_TYPE_GUID;
+ memcpy(&dev_desc->guid_sig, &pgpt_head->disk_guid,
+ sizeof(empty));
+ } else if (mbr->unique_mbr_signature != 0) {
+ dev_desc->sig_type = SIG_TYPE_MBR;
+ dev_desc->mbr_sig = mbr->unique_mbr_signature;
+ }
+ }
+
/* Read and allocate Partition Table Entries */
*pgpt_pte = alloc_read_gpt_entries(dev_desc, pgpt_head);
if (*pgpt_pte == NULL) {