Merge branch 'ctrl-mbr'

8 files changed, 439 insertions, 35 deletions

diff --git a/MCONFIG b/MCONFIG
index 9900ac4a..3fd3946d 100644
--- a/MCONFIG
+++ b/MCONFIG
@@ -36,6 +36,8 @@ NASMOPT  = -O9999
 
 PERL	 = perl
 
+CHMOD	 = chmod
+
 CC	 = gcc
 gcc_ok   = $(shell tmpf=gcc_ok.$$$$.tmp; \
 		   if $(CC) $(1) -c $(topdir)/dummy.c -o $$tmpf 2>/dev/null ; \
diff --git a/mbr/Makefile b/mbr/Makefile
index 0bdf7e3f..6cd677c0 100644
--- a/mbr/Makefile
+++ b/mbr/Makefile
@@ -1,6 +1,7 @@
 ## -----------------------------------------------------------------------
 ##
-##   Copyright 2007-2008 H. Peter Anvin - All Rights Reserved
+##   Copyright 2007-2009 H. Peter Anvin - All Rights Reserved
+##   Copyright 2009 Intel Corporation; author: H. Peter Anvin
 ##
 ##   This program is free software; you can redistribute it and/or modify
 ##   it under the terms of the GNU General Public License as published by
@@ -17,30 +18,31 @@
 topdir = ..
 include $(topdir)/MCONFIG.embedded
 
-all:	mbr.bin gptmbr.bin isohdpfx.bin
+all:	mbr.bin   altmbr.bin   gptmbr.bin   isohdpfx.bin   \
+	mbr_c.bin altmbr_c.bin gptmbr_c.bin isohdpfx_c.bin \
+	mbr_f.bin altmbr_f.bin gptmbr_f.bin isohdpfx_f.bin
 
 .PRECIOUS: %.o
-%.o: %.S
+%.o: %.S adjust.h
 	$(CC) $(SFLAGS) -Wa,-a=$*.lst -c -o $@ $<
 
+%_c.o: %.S adjust.h
+	$(CC) $(SFLAGS) -Wa,-a=$*_c.lst -DCTRL_80 -c -o $@ $<
+
+%_f.o: %.S adjust.h
+	$(CC) $(SFLAGS) -Wa,-a=$*_f.lst -DFORCE_80 -c -o $@ $<
+
 .PRECIOUS: %.elf
 %.elf: %.o mbr.ld
 	$(LD) $(LDFLAGS) -T mbr.ld -e _start -o $@ $<
 
-mbr.bin: mbr.elf checksize.pl
-	$(OBJCOPY) -O binary $< $@
-	$(PERL) checksize.pl $@ 440
-
-isohdpfx.bin: isohdpfx.elf checksize.pl
+%.bin: %.elf checksize.pl
 	$(OBJCOPY) -O binary $< $@
-	$(PERL) checksize.pl $@ 432
+	$(PERL) checksize.pl $@
+	$(CHMOD) -x $@
 
 mbr_bin.c: mbr.bin
 
-gptmbr.bin: gptmbr.elf checksize.pl
-	$(OBJCOPY) -O binary $< $@
-	$(PERL) checksize.pl $@ 424
-
 tidy dist:
 	rm -f *.o *.elf *.lst
 
diff --git a/mbr/adjust.h b/mbr/adjust.h
new file mode 100644
index 00000000..42c12a35
--- /dev/null
+++ b/mbr/adjust.h
@@ -0,0 +1,53 @@
+/* -*- asm -*- -----------------------------------------------------------
+ *
+ *   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
+ *   files (the "Software"), to deal in the Software without
+ *   restriction, including without limitation the rights to use,
+ *   copy, modify, merge, publish, distribute, sublicense, and/or
+ *   sell copies of the Software, and to permit persons to whom
+ *   the Software is furnished to do so, subject to the following
+ *   conditions:
+ *
+ *   The above copyright notice and this permission notice shall
+ *   be included in all copies or substantial portions of the Software.
+ *
+ *   THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+ *   EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES
+ *   OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+ *   NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
+ *   HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
+ *   WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+ *   FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
+ *   OTHER DEALINGS IN THE SOFTWARE.
+ *
+ * ----------------------------------------------------------------------- */
+
+/*
+ * adjust.h
+ *
+ * Macros to adjust the drive number
+ */
+
+#ifndef ADJUST_H
+#define ADJUST_H
+
+#ifdef CTRL_80
+	.macro ADJUST_DRIVE
+	testb	$0x04, BIOS_kbdflags
+	jz	1f
+	movb	$0x80, %dl
+1:
+	.endm
+#elif defined(FORCE_80)
+	.macro ADJUST_DRIVE
+	movb	$0x80, %dl
+	.endm
+#else
+	.macro ADJUST_DRIVE
+	.endm
+#endif
+
+#endif /* ADJUST_H */
diff --git a/mbr/altmbr.S b/mbr/altmbr.S
new file mode 100644
index 00000000..4a502ed0
--- /dev/null
+++ b/mbr/altmbr.S
@@ -0,0 +1,306 @@
+/* -----------------------------------------------------------------------
+ *
+ *   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
+ *   files (the "Software"), to deal in the Software without
+ *   restriction, including without limitation the rights to use,
+ *   copy, modify, merge, publish, distribute, sublicense, and/or
+ *   sell copies of the Software, and to permit persons to whom
+ *   the Software is furnished to do so, subject to the following
+ *   conditions:
+ *
+ *   The above copyright notice and this permission notice shall
+ *   be included in all copies or substantial portions of the Software.
+ *
+ *   THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+ *   EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES
+ *   OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+ *   NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
+ *   HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
+ *   WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+ *   FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
+ *   OTHER DEALINGS IN THE SOFTWARE.
+ *
+ * ----------------------------------------------------------------------- */
+
+#include "adjust.h"
+
+	.code16
+	.text
+
+	.globl	bootsec
+stack		= 0x7c00
+driveno		= (stack-6)
+sectors		= (stack-8)
+secpercyl	= (stack-12)
+
+BIOS_kbdflags	= 0x417
+BIOS_page	= 0x462
+
+	/* gas/ld has issues with doing this as absolute addresses... */
+	.section ".bootsec", "a", @nobits
+	.globl	bootsec
+bootsec:
+	.space	512
+
+	.text
+	.globl	_start
+_start:
+	cli
+	xorw	%ax, %ax
+	movw	%ax, %ds
+	movw	%ax, %ss
+	movw	$stack, %sp
+	movw	%sp, %si
+	pushw	%es		/* es:di -> $PnP header */
+	pushw	%di
+	movw	%ax, %es
+	sti
+	cld
+
+	/* Copy down to 0:0x600 */
+	movw	$_start, %di
+	movw	$(512/2), %cx
+	rep; movsw
+
+	ljmpw	$0, $next
+next:
+
+	ADJUST_DRIVE
+	pushw	%dx		/* dl -> drive number */
+
+	/* Check to see if we have EBIOS */
+	pushw	%dx		/* drive number */
+	movb	$0x41, %ah	/* %al == 0 already */
+	movw	$0x55aa, %bx
+	xorw	%cx, %cx
+	xorb	%dh, %dh
+	stc
+	int	$0x13
+	jc	1f
+	cmpw	$0xaa55, %bx
+	jne	1f
+	shrw	%cx		/* Bit 0 = fixed disk subset */
+	jnc	1f
+
+	/* We have EBIOS; patch in the following code at
+	   read_sector_cbios: movb $0x42, %ah ;  jmp read_common */
+	movl	$0xeb42b4+((read_common-read_sector_cbios-4) << 24), \
+		(read_sector_cbios)
+
+1:
+	popw	%dx
+
+	/* Get (C)HS geometry */
+	movb	$0x08, %ah
+	int	$0x13
+	andw	$0x3f, %cx	/* Sector count */
+	pushw	%cx		/* Save sectors on the stack */
+	movzbw	%dh, %ax	/* dh = max head */
+	incw	%ax		/* From 0-based max to count */
+	mulw	%cx		/* Heads*sectors -> sectors per cylinder */
+
+	/* Save sectors/cylinder on the stack */
+	pushw	%dx		/* High word */
+	pushw	%ax		/* Low word */
+
+	xorl	%eax, %eax	/* Base */
+	cdq			/* Root (%edx <- 0) */
+	call	scan_partition_table
+
+	/* If we get here, we have no OS */
+missing_os:
+	call	error
+	.ascii	"Missing operating system.\r\n"
+
+/*
+ * read_sector: read a single sector pointed to by %eax to 0x7c00.
+ * CF is set on error.  All registers saved.
+ */
+read_sector:
+	pushal
+	xorl	%edx, %edx
+	movw	$bootsec, %bx
+	pushl	%edx	/* MSW of LBA */
+	pushl	%eax	/* LSW of LBA */
+	pushw	%es	/* Buffer segment */
+	pushw	%bx	/* Buffer offset */
+	pushw	$1	/* Sector count */
+	pushw	$16	/* Size of packet */
+	movw	%sp, %si
+
+	/* This chunk is skipped if we have ebios */
+	/* Do not clobber %eax before this chunk! */
+	/* This also relies on %bx and %edx as set up above. */
+read_sector_cbios:
+	divl	(secpercyl)
+	shlb	$6, %ah
+	movb	%ah, %cl
+	movb	%al, %ch
+	xchgw	%dx, %ax
+	divb	(sectors)
+	movb	%al, %dh
+	orb	%ah, %cl
+	incw	%cx	/* Sectors are 1-based */
+	movw	$0x0201, %ax
+
+read_common:
+	movb	(driveno), %dl
+	int	$0x13
+	leaw	16(%si), %sp	/* Drop DAPA */
+	popal
+	ret
+
+/*
+ * read_partition_table:
+ *	Read a partition table (pointed to by %eax), and copy
+ *	the partition table into the ptab buffer.
+ *
+ *	Clobbers %si, %di, and %cx, other registers preserved.
+ *	%cx = 0 on exit.
+ *
+ *	On error, CF is set and ptab is overwritten with junk.
+ */
+ptab	= _start+446
+
+read_partition_table:
+	call	read_sector
+	movw	$bootsec+446, %si
+	movw	$ptab, %di
+	movw	$(16*4/2), %cx
+	rep ; movsw
+	ret
+
+/*
+ * scan_partition_table:
+ *	Scan a partition table currently loaded in the partition table
+ *	area.  Preserve all registers.
+ *
+ *      On entry:
+ *	  %eax - base (location of this partition table)
+ *	  %edx - root (offset from MBR, or 0 for MBR)
+ *
+ *      These get pushed into stack slots:
+ *        28(%bp) - %eax - base
+ *	  20(%bp) - %edx - root
+ */
+
+scan_partition_table:
+	pushal
+	movw	%sp, %bp
+
+	/* Scan the primary partition table */
+	movw	$ptab, %si
+	movw	$4, %cx
+	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" */
+
+	movb	4(%si), %al
+	cmpb	$0x0f, %al	/* 0x0f = Win9x extended */
+	je	8f
+	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
+	   try to scan it.  If the scan returns, re-load the current
+	   partition table and resume scan. */
+8:
+	movl	8(%si), %eax		/* Partition table offset */
+	addl	%edx, %eax		/* Compute location of new ptab */
+	andl	%edx, %edx		/* Is this the MBR? */
+	jnz	10f
+	movl	%eax, %edx		/* Offset -> root if this was MBR */
+10:
+	call	read_partition_table
+	jc	11f
+	call	scan_partition_table
+11:
+	/* This returned, so we need to reload the current partition table */
+	movl	28(%bp), %eax		/* "Base" */
+	call	read_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? */
+	/* If so, this is a logical partition */
+	decb	(partition)
+	je	boot
+12:
+	addw	$16, %si
+	loopw	7b
+
+	/* Nothing found, return */
+	popal
+	ret
+
+/*
+ * boot: invoke the actual bootstrap. (%si) points to the partition
+ *	 table entry, and 28(%bp) has the partition table base.
+ */
+boot:
+	cmpb	$0, 4(%si)
+	je	missing_os
+	movl	8(%si), %eax
+	addl	28(%bp), %eax
+	movl	%eax, 8(%si)	/* Adjust in-memory partition table entry */
+	call	read_sector
+	jc	disk_error
+	cmpw	$0xaa55, (bootsec+510)
+	jne	missing_os		/* Not a valid boot sector */
+	movw	$driveno, %sp	/* driveno == bootsec-6 */
+	popw	%dx		/* dl -> drive number */
+	popw	%di		/* es:di -> $PnP vector */
+	popw	%es
+	cli
+	jmpw	*%sp		/* %sp == bootsec */
+
+disk_error:
+	call	error
+	.ascii	"Operating system load error.\r\n"
+
+/*
+ * Print error messages.  This is invoked with "call", with the
+ * error message at the return address.
+ */
+error:
+	popw	%si
+2:
+	lodsb
+	movb	$0x0e, %ah
+	movb	(BIOS_page), %bh
+	movb	$0x07, %bl
+	int	$0x10		/* May destroy %bp */
+	cmpb	$10, %al	/* Newline? */
+	jne	2b
+
+	int	$0x18		/* Boot failure */
+die:
+	hlt
+	jmp	die
+
+/* Location of the partition configuration byte */
+partition = _start + 439
diff --git a/mbr/checksize.pl b/mbr/checksize.pl
index 68a035b7..4648c95c 100755
--- a/mbr/checksize.pl
+++ b/mbr/checksize.pl
@@ -1,6 +1,7 @@
 ## -----------------------------------------------------------------------
 ##
-##   Copyright 2007-2008 H. Peter Anvin - All Rights Reserved
+##   Copyright 2007-2009 H. Peter Anvin - All Rights Reserved
+##   Copyright 2009 Intel Corporation; author: H. Peter Anvin
 ##
 ##   This program is free software; you can redistribute it and/or modify
 ##   it under the terms of the GNU General Public License as published by
@@ -13,18 +14,41 @@
 ##
 ## checksize.pl
 ##
-## Check the size of a binary file
+## Check the size of a binary file and pad it with zeroes to that size
 ##
 
-($file, $maxsize) = @ARGV;
+use bytes;
 
-@st = stat($file);
+($file, $maxsize, $padsize) = @ARGV;
+
+if (!defined($maxsize)) {
+    # Defaults based on the filename
+    if ($file =~ /^mbr[^0-9a-z]/) {
+	$maxsize = $padsize = 440;
+    } elsif ($file =~ /^gptmbr[^0-9a-z]/) {
+	$maxsize = $padsize = 424;
+    } elsif ($file =~ /^isohdpfx[^0-9a-z]/) {
+	$maxsize = $padsize = 432;
+    } elsif ($file =~ /^altmbr[^0-9a-z]/) {
+	$maxsize = 439; $padsize = 440;
+    } else {
+	die "$0: no default size for filename: $file\n";
+    }
+}
+
+$padsize = $maxsize unless(defined($padsize));
+
+open(FILE, '+<', $file) or die;
+@st = stat(FILE);
 if (!defined($size = $st[7])) {
     die "$0: $file: $!\n";
 }
 if ($size > $maxsize) {
     print STDERR "$file: too big ($size > $maxsize)\n";
     exit 1;
-} else {
-    exit 0;
+} elsif ($size < $padsize) {
+    seek(FILE, $size, 0);
+    print FILE "\0" x ($padsize-$size);
 }
+
+exit 0;
diff --git a/mbr/gptmbr.S b/mbr/gptmbr.S
index 385afe74..8d42e8b8 100644
--- a/mbr/gptmbr.S
+++ b/mbr/gptmbr.S
@@ -1,6 +1,7 @@
 /* -----------------------------------------------------------------------
  *
- *   Copyright 2007-2008 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
 
@@ -42,6 +45,7 @@ bootguid	= _start + 0x1a8
 /* Where we put DS:SI */
 dssi_out	= _start + 0x1be
 
+BIOS_kbdflags	= 0x417
 BIOS_page	= 0x462
 
 	/* gas/ld has issues with doing this as absolute addresses... */
@@ -61,7 +65,6 @@ _start:
 	movw	%sp, %si
 	pushw	%es		/* 4(%bp) es:di -> $PnP header */
 	pushw	%di		/* 2(%bp) */
-	pushw	%dx		/* 0(%bp) = %dl -> drive number */
 	movw	%ax, %es
 	sti
 	cld
@@ -72,8 +75,11 @@ _start:
 	rep; movsw
 
 	ljmpw	$0, $next
-
 next:
+
+	ADJUST_DRIVE
+	pushw	%dx		/* 0(%bp) = %dl -> drive number */
+
 	/* Check to see if we have EBIOS */
 	pushw	%dx		/* drive number */
 	movb	$0x41, %ah	/* %al == 0 already */
@@ -163,10 +169,10 @@ find_part:
 
 found_part:
 	xchgw	%ax,%cx		/* Set up %cx for rep movsb further down */
-	
+
 	movw	$dssi_out,%di
 	pushw	%di
-	
+
 	/* 80 00 00 00 ee 00 00 00
 	   - bootable partition, type EFI (EE), no CHS information */
 	xorl	%eax,%eax
@@ -210,7 +216,7 @@ boot:
 
 missing_os:
 	call	error
-	.ascii	"Operating system not bootable\r\n"
+	.ascii	"OS not bootable\r\n"
 
 saturate_stosl:
 	pushl	%eax
diff --git a/mbr/isohdpfx.S b/mbr/isohdpfx.S
index 4da49468..f42b4b5b 100644
--- a/mbr/isohdpfx.S
+++ b/mbr/isohdpfx.S
@@ -33,12 +33,14 @@
  * loader of a hard-coded offset, but that's good enough to load
  * ISOLINUX.
  */
-	
+
+#include "adjust.h"
+
 	.code16
 	.text
 
 HYBRID_MAGIC			= 0x7078c0fb
-isolinux_hybrid_signature 	= 0x7c00+64
+isolinux_hybrid_signature	= 0x7c00+64
 isolinux_start_hybrid		= 0x7c00+64+4
 
 	.globl	bootsec
@@ -50,7 +52,8 @@ sectors		= (stack-10)
 heads		= (stack-12)
 secpercyl	= (stack-16)
 
-BIOS_page = 0x462
+BIOS_kbdflags	= 0x417
+BIOS_page	= 0x462
 
 	/* gas/ld has issues with doing this as absolute addresses... */
 	.section ".bootsec", "a", @nobits
@@ -70,7 +73,6 @@ _start:
 	movw	%sp, %si
 	pushw	%es		/* es:di -> $PnP header */
 	pushw	%di
-	pushw	%dx		/* dl -> drive number */
 	movw	%ax, %es
 	sti
 	cld
@@ -81,8 +83,11 @@ _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 */
 	movb	$0x41, %ah	/* %al == 0 already */
@@ -141,7 +146,7 @@ next:
 	 */
 	cmpl	$HYBRID_MAGIC,(isolinux_hybrid_signature)
 	jne	bad_signature
-	
+
 	cli
 	movw	$heads, %sp
 
diff --git a/mbr/mbr.S b/mbr/mbr.S
index 722d90db..7caf4fc4 100644
--- a/mbr/mbr.S
+++ b/mbr/mbr.S
@@ -1,6 +1,7 @@
 /* -----------------------------------------------------------------------
  *
- *   Copyright 2007-2008 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
@@ -53,7 +57,6 @@ _start:
 	movw	%sp, %si
 	pushw	%es		/* es:di -> $PnP header */
 	pushw	%di
-	pushw	%dx		/* dl -> drive number */
 	movw	%ax, %es
 	sti
 	cld
@@ -64,8 +67,11 @@ _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 */
 	movb	$0x41, %ah	/* %al == 0 already */