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Fix parsing of Protective MBR and GPT headers

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git-svn-id: svn://kolibrios.org@6828 a494cfbc-eb01-0410-851d-a64ba20cac60
This commit is contained in:
Ivan Baravy 2017-01-18 21:05:31 +00:00
parent 34df6be0da
commit 56b3fa9987
1 changed files with 8 additions and 6 deletions
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14
kernel/trunk/blkdev/disk.inc
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@ -227,7 +227,7 @@ struct GPTH
HeaderCRC32 dd ? HeaderCRC32 dd ?
; Set this field to zero, compute CRC32 via 0xEDB88320, compare. ; Set this field to zero, compute CRC32 via 0xEDB88320, compare.
Reserved dd ? Reserved dd ?
; Myst be zero. ; Must be zero.
MyLBA dq ? MyLBA dq ?
; LBA of the sector containing this GPT header. ; LBA of the sector containing this GPT header.
AlternateLBA dq ? AlternateLBA dq ?
@ -846,6 +846,7 @@ disk_scan_partitions:
; This function is called from disk_scan_partitions to validate and parse ; This function is called from disk_scan_partitions to validate and parse
; primary and backup GPTs. ; primary and backup GPTs.
proc disk_scan_gpt proc disk_scan_gpt
push ecx
; Scan primary GPT (second sector) ; Scan primary GPT (second sector)
stdcall scan_gpt, 1, 0 stdcall scan_gpt, 1, 0
test eax, eax test eax, eax
@ -864,6 +865,7 @@ proc disk_scan_gpt
DEBUGF 1, 'K : Backup GPT is also corrupt, fallback to legacy MBR\n' DEBUGF 1, 'K : Backup GPT is also corrupt, fallback to legacy MBR\n'
.exit: .exit:
; Return value is ZF ; Return value is ZF
pop ecx
ret ret
endp endp
@ -955,8 +957,8 @@ endl
mov al, DISKFUNC.read mov al, DISKFUNC.read
stdcall disk_call_driver, edi, dword[ebx+GPTH.PartitionEntryLBA+0], \ stdcall disk_call_driver, edi, dword[ebx+GPTH.PartitionEntryLBA+0], \
dword[ebx+GPTH.PartitionEntryLBA+4], esp dword[ebx+GPTH.PartitionEntryLBA+4], esp
pop ecx
test eax, eax test eax, eax
pop eax
jnz .fail_free_gpea_gpt jnz .fail_free_gpea_gpt
; Compute and check CRC32 of GPEA ; Compute and check CRC32 of GPEA
mov edx, [ebx+GPTH.PartitionEntryArrayCRC32] mov edx, [ebx+GPTH.PartitionEntryArrayCRC32]
@ -1009,12 +1011,12 @@ endp
is_protective_mbr: is_protective_mbr:
push ecx edi push ecx edi
xor eax, eax xor eax, eax
cmp [ecx-6], eax ; cmp [ecx-6], eax
jnz .exit ; jnz .exit
cmp [ecx-2], eax cmp [ecx-2], ax
jnz .exit jnz .exit
; Partition record 0 has specific fields ; Partition record 0 has specific fields
cmp dword[ecx+0], 0x00020000 cmp [ecx+0], al
jnz .exit jnz .exit
cmp byte[ecx+4], 0xEE cmp byte[ecx+4], 0xEE
jnz .exit jnz .exit