Files
xen/tools/misc/mbootpack/bootsect.S
T
tjd21@arcadians.cl.cam.ac.uk 4ceed52eee bitkeeper revision 1.1236.1.149 (42492762NRUXAIqtzpmd2lX5HSPVog)
Added the mbootpack tool, which packages multiboot boot files and
disguises them as a linux bzImage.  Useful for booting Xen using
pxelinux, or another linux-only bootloader.

Signed-off-by: Tim Deegan <Tim.Deegan@cl.cam.ac.uk>
2005-03-29 10:01:06 +00:00

137 lines
3.3 KiB
ArmAsm

/*
* bootsect.S
*
* This is bootsect.S from the linux 2.6.9 sources,
* with minor changes for mbootpack.
*
*
* 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 the Free Software Foundation; either version 2 of the
* License, or (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA
* 02111-1307, USA.
*
* $Id: bootsect.S,v 1.2 2005/03/23 10:39:11 tjd21 Exp $
*
*/
#include "mbootpack.h"
/*
* bootsect.S Copyright (C) 1991, 1992 Linus Torvalds
*
* modified by Drew Eckhardt
* modified by Bruce Evans (bde)
* modified by Chris Noe (May 1999) (as86 -> gas)
* gutted by H. Peter Anvin (Jan 2003)
*
* BIG FAT NOTE: We're in real mode using 64k segments. Therefore segment
* addresses must be multiplied by 16 to obtain their respective linear
* addresses. To avoid confusion, linear addresses are written using leading
* hex while segment addresses are written as segment:offset.
*
*/
/* #include <asm/boot.h> */
/* Definitions we should have got from there */
#define DEF_INITSEG 0x9000
#define DEF_SYSSEG 0x1000
#define DEF_SETUPSEG 0x9020
#define DEF_SYSSIZE 0x7F00
#define NORMAL_VGA 0xffff
#define EXTENDED_VGA 0xfffe
#define ASK_VGA 0xfffd
/* SETUPSECTS = 4 */ /* default nr of setup-sectors */
BOOTSEG = 0x07C0 /* original address of boot-sector */
INITSEG = DEF_INITSEG /* we move boot here - out of the way */
SETUPSEG = DEF_SETUPSEG /* setup starts here */
SYSSEG = DEF_SYSSEG /* system loaded at 0x10000 (65536) */
SYSSIZE = DEF_SYSSIZE /* system size: # of 16-byte clicks */
/* to be loaded */
ROOT_DEV = 0 /* ROOT_DEV is now written by "build" */
SWAP_DEV = 0 /* SWAP_DEV is now written by "build" */
#ifndef SVGA_MODE
/* #define SVGA_MODE ASK_VGA */
#define SVGA_MODE NORMAL_VGA
#endif
#ifndef RAMDISK
#define RAMDISK 0
#endif
#ifndef ROOT_RDONLY
#define ROOT_RDONLY 1
#endif
.code16
.text
.global _start
_start:
# Normalize the start address
jmpl $BOOTSEG, $start2
start2:
movw %cs, %ax
movw %ax, %ds
movw %ax, %es
movw %ax, %ss
movw $0x7c00, %sp
sti
cld
movw $bugger_off_msg, %si
msg_loop:
lodsb
andb %al, %al
jz die
movb $0xe, %ah
movw $7, %bx
int $0x10
jmp msg_loop
die:
# Allow the user to press a key, then reboot
xorw %ax, %ax
int $0x16
int $0x19
# int 0x19 should never return. In case it does anyway,
# invoke the BIOS reset code...
ljmp $0xf000,$0xfff0
bugger_off_msg:
.ascii "Direct booting from floppy is no longer supported.\r\n"
.ascii "Please use a boot loader program instead.\r\n"
.ascii "\n"
.ascii "Remove disk and press any key to reboot . . .\r\n"
.byte 0
# Kernel attributes; used by setupbegtext
.org 497
setup_sects: .byte SETUPSECTS
root_flags: .word ROOT_RDONLY
syssize: .word SYSSIZE
swap_dev: .word SWAP_DEV
ram_size: .word RAMDISK
vid_mode: .word SVGA_MODE
root_dev: .word ROOT_DEV
boot_flag: .word 0xAA55