X-Git-Url: http://review.tizen.org/git/?a=blobdiff_plain;f=mbr%2Fmbr.S;h=b71cfb7c4d8ee54ba8fdf6eae2b934d70c6447be;hb=61f106ba8a5b2a7c2d9855291fd9e7f4a4d3143d;hp=2a318be3896e7ebac6bfa0405fd2b9f549ed1be0;hpb=b19e0b33ad57d71635c55d9724cdff45daa24d73;p=profile%2Fivi%2Fsyslinux.git

diff --git a/mbr/mbr.S b/mbr/mbr.S
index 2a318be..b71cfb7 100644
--- a/mbr/mbr.S
+++ b/mbr/mbr.S
@@ -1,6 +1,7 @@
 /* -----------------------------------------------------------------------
  *
- *   Copyright 2007 H. Peter Anvin - All Rights Reserved
+ *   Copyright 2007-2009 H. Peter Anvin - All Rights Reserved
+ *   Copyright 2009 Intel Corporation; author: H. Peter Anvin
  *
  *   Permission is hereby granted, free of charge, to any person
  *   obtaining a copy of this software and associated documentation
@@ -25,6 +26,8 @@
  *
  * ----------------------------------------------------------------------- */
 
+#include "adjust.h"
+
 	.code16
 	.text
 
@@ -34,7 +37,8 @@ driveno		= (stack-6)
 sectors		= (stack-8)
 secpercyl	= (stack-12)
 
-BIOS_page = 0x462
+BIOS_kbdflags	= 0x417
+BIOS_page	= 0x462
 
 	/* gas/ld has issues with doing this as absolute addresses... */
 	.section ".bootsec", "a", @nobits
@@ -45,15 +49,14 @@ bootsec:
 	.text
 	.globl	_start
 _start:
+	.byte	0x33, 0xc0	/* xorw	%ax, %ax */
 	cli
-	xorw	%ax, %ax
 	movw	%ax, %ds
 	movw	%ax, %ss
 	movw	$stack, %sp
 	movw	%sp, %si
 	pushw	%es		/* es:di -> $PnP header */
 	pushw	%di
-	pushw	%dx		/* dl -> drive number */
 	movw	%ax, %es
 	sti
 	cld
@@ -64,11 +67,14 @@ _start:
 	rep; movsw
 
 	ljmpw	$0, $next
-
 next:
+
+	ADJUST_DRIVE
+	pushw	%dx		/* dl -> drive number */
+
 	/* Check to see if we have EBIOS */
 	pushw	%dx		/* drive number */
-	movw	$0x4100, %ax
+	movb	$0x41, %ah	/* %al == 0 already */
 	movw	$0x55aa, %bx
 	xorw	%cx, %cx
 	xorb	%dh, %dh
@@ -109,7 +115,6 @@ next:
 missing_os:
 	call	error
 	.ascii	"Missing operating system.\r\n"
-	.byte	0
 
 /*
  * read_sector: read a single sector pointed to by %eax to 0x7c00.
@@ -145,7 +150,7 @@ read_sector_cbios:
 read_common:
 	movb	(driveno), %dl
 	int	$0x13
-	addw	$16, %sp	/* Drop DAPA */
+	leaw	16(%si), %sp	/* Drop DAPA */
 	popal
 	ret
 
@@ -207,8 +212,8 @@ scan_partition_table:
 	jns	too_many_active
 
 	/* No active partitions found, look for extended partitions */
-	popw	%bx		/* %bx <- ptab */
 	popw	%cx		/* %cx <- 4    */
+	popw	%bx		/* %bx <- ptab */
 7:
 	movb	4(%bx), %al
 	cmpb	$0x0f, %al	/* 0x0f = Win9x extended */
@@ -249,7 +254,6 @@ scan_partition_table:
 too_many_active:
 	call	error
 	.ascii	"Multiple active partitions.\r\n"
-	.byte	0
 
 /*
  * boot: invoke the actual bootstrap. (%si) points to the partition
@@ -273,7 +277,6 @@ boot:
 disk_error:
 	call	error
 	.ascii	"Operating system load error.\r\n"
-	.byte	0
 
 /*
  * Print error messages.  This is invoked with "call", with the
@@ -283,14 +286,13 @@ error:
 	popw	%si
 2:
 	lodsb
-	andb	%al, %al
-	jz	3f
 	movb	$0x0e, %ah
 	movb	(BIOS_page), %bh
 	movb	$0x07, %bl
-	int	$0x10
-	jmp	2b
-3:
+	int	$0x10		/* May destroy %bp */
+	cmpb	$10, %al	/* Newline? */
+	jne	2b
+
 	int	$0x18		/* Boot failure */
 die:
 	hlt