mbr: generate normal versions, force-80 versions, and ctrl-80 versions

Produce MBR variants with normal (DL) behavior, force to drive 80
behavior, and force to 80 on Ctrl pressed behavior.

Signed-off-by: H. Peter Anvin <hpa@zytor.com>

7 files changed, 107 insertions, 46 deletions

diff --git a/mbr/Makefile b/mbr/Makefile
index e9fc3875..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
@@ -17,34 +18,31 @@
 topdir = ..
 include $(topdir)/MCONFIG.embedded
 
-all:	mbr.bin altmbr.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
-
-altmbr.bin: altmbr.elf checksize.pl
+%.bin: %.elf checksize.pl
 	$(OBJCOPY) -O binary $< $@
-	$(PERL) checksize.pl $@ 439 440
-
-isohdpfx.bin: isohdpfx.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
index b85bf8be..4a502ed0 100644
--- a/mbr/altmbr.S
+++ b/mbr/altmbr.S
@@ -26,6 +26,8 @@
  *
  * ----------------------------------------------------------------------- */
 
+#include "adjust.h"
+
 	.code16
 	.text
 
@@ -66,12 +68,8 @@ _start:
 
 	ljmpw	$0, $next
 next:
-	
-	/* Escape for the user: if Ctrl is pressed, assume drive hd0 */
-	testb	$0x04, BIOS_kbdflags	/* Ctrl pressed */
-	jz	1f
-	movb	$0x80, %dl
-1:
+
+	ADJUST_DRIVE
 	pushw	%dx		/* dl -> drive number */
 
 	/* Check to see if we have EBIOS */
diff --git a/mbr/checksize.pl b/mbr/checksize.pl
index a3643101..4648c95c 100755
--- a/mbr/checksize.pl
+++ b/mbr/checksize.pl
@@ -1,6 +1,7 @@
 ## -----------------------------------------------------------------------
 ##
 ##   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
@@ -20,6 +21,21 @@ use bytes;
 
 ($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;
diff --git a/mbr/gptmbr.S b/mbr/gptmbr.S
index 6df67f42..8d42e8b8 100644
--- a/mbr/gptmbr.S
+++ b/mbr/gptmbr.S
@@ -26,6 +26,8 @@
  *
  * ----------------------------------------------------------------------- */
 
+#include "adjust.h"
+
 	.code16
 	.text
 
@@ -74,11 +76,8 @@ _start:
 
 	ljmpw	$0, $next
 next:
-	/* Escape for the user: if Ctrl is pressed, assume drive hd0 */
-	testb	$0x04, BIOS_kbdflags	/* Ctrl pressed */
-	jz	1f
-	movb	$0x80, %dl
-1:
+
+	ADJUST_DRIVE
 	pushw	%dx		/* 0(%bp) = %dl -> drive number */
 
 	/* Check to see if we have EBIOS */
@@ -170,10 +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
diff --git a/mbr/isohdpfx.S b/mbr/isohdpfx.S
index 0c5b95e6..f42b4b5b 100644
--- a/mbr/isohdpfx.S
+++ b/mbr/isohdpfx.S
@@ -1,6 +1,7 @@
 /* -----------------------------------------------------------------------
  *
  *   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
@@ -32,12 +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
@@ -81,12 +84,8 @@ _start:
 
 	ljmpw	$0, $next
 next:
-	
-	/* Escape for the user: if Ctrl is pressed, assume drive hd0 */
-	testb	$0x04, BIOS_kbdflags	/* Ctrl pressed */
-	jz	1f
-	movb	$0x80, %dl
-1:
+
+	ADJUST_DRIVE
 	pushw	%dx		/* dl -> drive number */
 
 	/* Check to see if we have EBIOS */
@@ -147,7 +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 2407663e..7caf4fc4 100644
--- a/mbr/mbr.S
+++ b/mbr/mbr.S
@@ -26,6 +26,8 @@
  *
  * ----------------------------------------------------------------------- */
 
+#include "adjust.h"
+
 	.code16
 	.text
 
@@ -37,7 +39,7 @@ 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
@@ -66,12 +68,8 @@ _start:
 
 	ljmpw	$0, $next
 next:
-	
-	/* Escape for the user: if Ctrl is pressed, assume drive hd0 */
-	testb	$0x04, BIOS_kbdflags	/* Ctrl pressed */
-	jz	1f
-	movb	$0x80, %dl
-1:
+
+	ADJUST_DRIVE
 	pushw	%dx		/* dl -> drive number */
 
 	/* Check to see if we have EBIOS */