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MdeModulePkg/PartitionDxe: Revert changes for the special MBR

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REF: https://bugzilla.tianocore.org/show_bug.cgi?id=2823

Revert "MdeModulePkg/PartitionDxe: Skip the MBR that add for CD-ROM"

Follow the spec definition, the ISO 9660 (and UDF) would be
checked before the MBR. So it is not required to skip such
MBR talbe that contian the entire block device.

Cc: Jian J Wang <jian.j.wang@intel.com>
Cc: Hao A Wu <hao.a.wu@intel.com>
Cc: Ray Ni <ray.ni@intel.com>
Cc: Gary Lin <glin@suse.com>
Cc: Andrew Fish <afish@apple.com>
Signed-off-by: Zhichao Gao <zhichao.gao@intel.com>
Reviewed-by: Ray Ni <ray.ni@intel.com>
Reviewed-by: Hao A Wu <hao.a.wu@intel.com>
Tested-by: Gary Lin <glin@suse.com>
This commit is contained in:
Zhichao Gao 2020-08-12 09:07:05 +08:00 committed by mergify[bot]
parent f0f7140150
commit 94b7df5c4a
1 changed files with 6 additions and 31 deletions
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37
MdeModulePkg/Universal/Disk/PartitionDxe/Mbr.c
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@ -39,7 +39,6 @@ PartitionValidMbr (
UINT32 StartingLBA;
UINT32 EndingLBA;
UINT32 NewEndingLBA;
UINT32 SizeInLBA;
INTN Index1;
INTN Index2;
BOOLEAN MbrValid;
@ -52,34 +51,13 @@ PartitionValidMbr (
//
MbrValid = FALSE;
for (Index1 = 0; Index1 < MAX_MBR_PARTITIONS; Index1++) {
StartingLBA = UNPACK_UINT32 (Mbr->Partition[Index1].StartingLBA);
SizeInLBA = UNPACK_UINT32 (Mbr->Partition[Index1].SizeInLBA);
//
// If the MBR with partition entry covering the ENTIRE disk, i.e. start at LBA0
// with whole disk size, we treat it as an invalid MBR partition.
//
if ((StartingLBA == 0) &&
(SizeInLBA == (LastLba + 1))) {
//
// Refer to the http://manpages.ubuntu.com/manpages/bionic/man8/mkudffs.8.html
// "WHOLE DISK VS PARTITION"
// Some linux ISOs may put the MBR table in the first 512 bytes for compatibility reasons with Windows.
// Linux kernel ignores MBR table if contains partition which starts at sector 0.
// Skip it because we don't have the partition check for UDF(El Torito compatible).
// It would continue to do the whole disk check in the UDF routine.
//
DEBUG ((DEBUG_INFO, "PartitionValidMbr: MBR table has partition entry covering the ENTIRE disk. Don't treat it as a valid MBR.\n"));
return FALSE;
}
if (Mbr->Partition[Index1].OSIndicator == 0x00 || SizeInLBA == 0) {
if (Mbr->Partition[Index1].OSIndicator == 0x00 || UNPACK_UINT32 (Mbr->Partition[Index1].SizeInLBA) == 0) {
continue;
}
MbrValid = TRUE;
EndingLBA = StartingLBA + SizeInLBA - 1;
StartingLBA = UNPACK_UINT32 (Mbr->Partition[Index1].StartingLBA);
EndingLBA = StartingLBA + UNPACK_UINT32 (Mbr->Partition[Index1].SizeInLBA) - 1;
if (EndingLBA > LastLba) {
//
// Compatibility Errata:
@ -99,15 +77,12 @@ PartitionValidMbr (
}
for (Index2 = Index1 + 1; Index2 < MAX_MBR_PARTITIONS; Index2++) {
StartingLBA = UNPACK_UINT32 (Mbr->Partition[Index2].StartingLBA);
SizeInLBA = UNPACK_UINT32 (Mbr->Partition[Index2].SizeInLBA);
if (Mbr->Partition[Index2].OSIndicator == 0x00 || SizeInLBA == 0) {
if (Mbr->Partition[Index2].OSIndicator == 0x00 || UNPACK_UINT32 (Mbr->Partition[Index2].SizeInLBA) == 0) {
continue;
}
NewEndingLBA = StartingLBA + SizeInLBA - 1;
if (NewEndingLBA >= StartingLBA && StartingLBA <= EndingLBA) {
NewEndingLBA = UNPACK_UINT32 (Mbr->Partition[Index2].StartingLBA) + UNPACK_UINT32 (Mbr->Partition[Index2].SizeInLBA) - 1;
if (NewEndingLBA >= StartingLBA && UNPACK_UINT32 (Mbr->Partition[Index2].StartingLBA) <= EndingLBA) {
//
// This region overlaps with the Index1'th region
//