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| author | H. Peter Anvin <hpa@zytor.com> | 2009-05-25 15:37:28 -0700 |
|---|---|---|
| committer | H. Peter Anvin <hpa@zytor.com> | 2009-05-25 15:37:28 -0700 |
| commit | dc688778521d28b28596386d67af28bc1d7e6d1c (patch) | |
| tree | 4b89a9889758d6883b57bf2ac95e2ddb73945a20 /mbr | |
| parent | 9d1cde418a4f0dc6cccf4af7eae340e75de2f3d4 (diff) | |
| download | syslinux-dc688778521d28b28596386d67af28bc1d7e6d1c.tar.gz syslinux-dc688778521d28b28596386d67af28bc1d7e6d1c.tar.xz syslinux-dc688778521d28b28596386d67af28bc1d7e6d1c.zip | |
altmbr: fix accounting of logical partitions
Unlike the main MBR, we need to keep careful count when we process
logical partitions... and we weren't.
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Diffstat (limited to 'mbr')
| -rw-r--r-- | mbr/altmbr.S | 28 |
1 files changed, 13 insertions, 15 deletions
diff --git a/mbr/altmbr.S b/mbr/altmbr.S index 4a502ed0..794ab623 100644 --- a/mbr/altmbr.S +++ b/mbr/altmbr.S @@ -195,31 +195,30 @@ scan_partition_table: /* Scan the primary partition table */ movw $ptab, %si movw $4, %cx + /* Is it a primary partition table? */ + andl %edx, %edx + jnz 7f push %si push %cx - /* Is it a primary partition? */ - andl %edx, %edx - jnz 6f - 5: decb (partition) jz boot addw $16, %bx loopw 5b -6: - /* No active partitions found, look for extended partitions */ - popw %cx /* %cx <- 4 */ - popw %si /* %si <- ptab */ -7: - movl 20(%bp), %edx /* "Root" */ + popw %cx /* %cx <- 4 */ + popw %si /* %si <- ptab */ + /* No primary partitions found, look for extended/logical partitions */ +7: movb 4(%si), %al - cmpb $0x0f, %al /* 0x0f = Win9x extended */ + andb %al, %al + jz 12f /* Not a valid partition */ + cmpb $0x0f, %al /* 0x0f = Win9x extended */ je 8f - andb $~0x80, %al /* 0x85 = Linux extended */ - cmpb $0x05, %al /* 0x05 = MS-DOS extended */ + andb $~0x80, %al /* 0x85 = Linux extended */ + cmpb $0x05, %al /* 0x05 = MS-DOS extended */ jne 9f /* It is an extended partition. Read the extended partition and @@ -243,9 +242,8 @@ scan_partition_table: /* fall through */ 9: /* Not an extended partition */ - andb %al, %al - jz 12f /* Not a valid partition */ andl %edx, %edx /* Are we inside an extended part? */ + jz 12f /* If so, this is a logical partition */ decb (partition) je boot |