Module Name: src
Committed By: jakllsch
Date: Wed Aug 17 00:07:39 UTC 2011
Modified Files:
src/sys/arch/i386/stand/bootxx: pbr.S
Log Message:
Remove home grown GPT MBR handoff support in favor of T13 EDD-4 annex A,
which does the same thing in a more interoperable way.
To generate a diff of this commit:
cvs rdiff -u -r1.19 -r1.20 src/sys/arch/i386/stand/bootxx/pbr.S
Please note that diffs are not public domain; they are subject to the
copyright notices on the relevant files.
Modified files:
Index: src/sys/arch/i386/stand/bootxx/pbr.S
diff -u src/sys/arch/i386/stand/bootxx/pbr.S:1.19 src/sys/arch/i386/stand/bootxx/pbr.S:1.20
--- src/sys/arch/i386/stand/bootxx/pbr.S:1.19 Thu Jan 6 01:08:48 2011
+++ src/sys/arch/i386/stand/bootxx/pbr.S Wed Aug 17 00:07:38 2011
@@ -1,4 +1,4 @@
-/* $NetBSD: pbr.S,v 1.19 2011/01/06 01:08:48 jakllsch Exp $ */
+/* $NetBSD: pbr.S,v 1.20 2011/08/17 00:07:38 jakllsch Exp $ */
/*-
* Copyright (c) 2003,2004 The NetBSD Foundation, Inc.
@@ -97,8 +97,9 @@
* sector we were loaded from (if we were loaded by NetBSD mbr code).
* In any case we have to re-read sector zero of the disk and hunt
* through the BIOS partition table for the NetBSD partition.
- * However, if there's a magic number in %eax, then %ecx:%ebx
- * contains the sector we were loaded from.
+ *
+ * Or, we may have been loaded by a GPT hybrid MBR, handoff state is
+ * specified in T13 EDD-4 annex A.
*/
.text
@@ -121,19 +122,16 @@
. = start + MBR_AFTERBPB /* skip BPB */
start0:
+ xor %cx, %cx /* don't trust values of ds, es or ss */
+ mov %cx, %ss
+ mov %cx, %sp
+ mov %cx, %es
#ifndef BOOT_FROM_FAT
- movl %eax, %edi /* move %eax magic out of the way */
-#endif
- xor %ax, %ax /* don't trust values of ds, es or ss */
- mov %ax, %ds
- mov %ax, %es
- mov %ax, %ss
- mov $0xfffc, %sp
-
-#ifndef BOOT_FROM_FAT
- cmpl $X86_MBR_GPT_MAGIC, %edi /* did mbr_gpt leave us a LBA? */
+ cmpl $0x54504721, %eax /* did a GPT hybrid MBR start us? */
je boot_gpt
#endif
+ mov %cx, %ds
+ xor %ax, %ax
/* A 'reset disk system' request is traditional here... */
push %dx /* some BIOS zap %dl here :-( */
@@ -141,7 +139,7 @@
pop %dx
/* Read from start of disk */
- movw $0x0001, %cx /* track zero sector 1 */
+ incw %cx /* track zero sector 1 */
movb %ch, %dh /* dh = head = 0 */
call chs_read
@@ -368,10 +366,12 @@
#ifndef BOOT_FROM_FAT
boot_gpt:
- /* 64-bit LBA in %ecx:%ebx */
- movl %ebx, lba_sector
- movl %ecx, lba_sector + 4
- movl %ebx, %ebp
+ movl (20+32+0)(%si), %ebp
+ movl (20+32+4)(%si), %edi
+ movw %cx, %ds
+ movl %ebp, lba_sector + 0
+ movl %edi, lba_sector + 4
+ movl %ebp, %esi
jmp boot_lba
#endif
