324 lines
7.1 KiB
ArmAsm
324 lines
7.1 KiB
ArmAsm
|
/*
|
||
|
|
* Ported to boot 386BSD by Julian Elischer (julian@tfs.com) Sept 1992
|
||
|
|
*
|
||
|
|
* Mach Operating System
|
||
|
|
* Copyright (c) 1992, 1991 Carnegie Mellon University
|
||
|
|
* All Rights Reserved.
|
||
|
|
*
|
||
|
|
* Permission to use, copy, modify and distribute this software and its
|
||
|
|
* documentation is hereby granted, provided that both the copyright
|
||
|
|
* notice and this permission notice appear in all copies of the
|
||
|
|
* software, derivative works or modified versions, and any portions
|
||
|
|
* thereof, and that both notices appear in supporting documentation.
|
||
|
|
*
|
||
|
|
* CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS"
|
||
|
|
* CONDITION. CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND FOR
|
||
|
|
* ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
|
||
|
|
*
|
||
|
|
* Carnegie Mellon requests users of this software to return to
|
||
|
|
*
|
||
|
|
* Software Distribution Coordinator or Software.Distribution@CS.CMU.EDU
|
||
|
|
* School of Computer Science
|
||
|
|
* Carnegie Mellon University
|
||
|
|
* Pittsburgh PA 15213-3890
|
||
|
|
*
|
||
|
|
* any improvements or extensions that they make and grant Carnegie Mellon
|
||
|
|
* the rights to redistribute these changes.
|
||
|
|
*/
|
||
|
|
|
||
|
|
/*
|
||
|
|
* HISTORY
|
||
|
|
* $Log: start.s,v $
|
||
|
|
* Revision 2.2 92/04/04 11:36:29 rpd
|
||
|
|
* Fix Intel Copyright as per B. Davies authorization.
|
||
|
|
* [92/04/03 rvb]
|
||
|
|
* Need to zero dh on hd path; at least for an adaptec card.
|
||
|
|
* [92/01/14 rvb]
|
||
|
|
*
|
||
|
|
* From 2.5 boot:
|
||
|
|
* Flush digit printing.
|
||
|
|
* Fuse floppy and hd boot by using Int 21 to tell
|
||
|
|
* boot type (slightly dubious since Int 21 is DOS
|
||
|
|
* not BIOS)
|
||
|
|
* [92/03/30 mg32]
|
||
|
|
*
|
||
|
|
* Revision 2.2 91/04/02 14:42:04 mbj
|
||
|
|
* Fix the BIG boot bug. We had missed a necessary data
|
||
|
|
* before a xor that was clearing a register used later
|
||
|
|
* as an index register.
|
||
|
|
* [91/03/01 rvb]
|
||
|
|
* Remember floppy type for swapgeneric
|
||
|
|
* Add Intel copyright
|
||
|
|
* [90/02/09 rvb]
|
||
|
|
*
|
||
|
|
*/
|
||
|
|
|
||
|
|
|
||
|
|
/*
|
||
|
|
Copyright 1988, 1989, 1990, 1991, 1992
|
||
|
|
by Intel Corporation, Santa Clara, California.
|
||
|
|
|
||
|
|
All Rights Reserved
|
||
|
|
|
||
|
|
Permission to use, copy, modify, and distribute this software and
|
||
|
|
its documentation for any purpose and without fee is hereby
|
||
|
|
granted, provided that the above copyright notice appears in all
|
||
|
|
copies and that both the copyright notice and this permission notice
|
||
|
|
appear in supporting documentation, and that the name of Intel
|
||
|
|
not be used in advertising or publicity pertaining to distribution
|
||
|
|
of the software without specific, written prior permission.
|
||
|
|
|
||
|
|
INTEL DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE
|
||
|
|
INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS,
|
||
|
|
IN NO EVENT SHALL INTEL BE LIABLE FOR ANY SPECIAL, INDIRECT, OR
|
||
|
|
CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
|
||
|
|
LOSS OF USE, DATA OR PROFITS, WHETHER IN ACTION OF CONTRACT,
|
||
|
|
NEGLIGENCE, OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION
|
||
|
|
WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
|
||
|
|
*/
|
||
|
|
#include "asm.h"
|
||
|
|
|
||
|
|
.file "start.s"
|
||
|
|
|
||
|
|
BOOTSEG = 0x9000 # boot will be loaded at 640k-64k
|
||
|
|
BOOTSTACK = 0xe000 # boot stack
|
||
|
|
SIGNATURE = 0xaa55
|
||
|
|
LOADSZ = 14 # size of unix boot
|
||
|
|
PARTSTART = 0x1be # starting address of partition table
|
||
|
|
NUMPART = 4 # number of partitions in partition table
|
||
|
|
PARTSZ = 16 # each partition table entry is 16 bytes
|
||
|
|
BSDPART = 0xA5 # value of boot_ind, means bootable partition
|
||
|
|
BOOTABLE = 0x80 # value of boot_ind, means bootable partition
|
||
|
|
|
||
|
|
.text
|
||
|
|
|
||
|
|
ENTRY(boot1)
|
||
|
|
|
||
|
|
# boot1 is loaded at 0x0:0x7c00
|
||
|
|
# ljmp to the next instruction to set up %cs
|
||
|
|
data32
|
||
|
|
ljmp $0x7c0, $start
|
||
|
|
|
||
|
|
start:
|
||
|
|
# set up %ds
|
||
|
|
mov %cs, %ax
|
||
|
|
mov %ax, %ds
|
||
|
|
|
||
|
|
|
||
|
|
# set up %ss and %esp
|
||
|
|
data32
|
||
|
|
mov $BOOTSEG, %eax
|
||
|
|
mov %ax, %ss
|
||
|
|
data32
|
||
|
|
mov $BOOTSTACK, %esp
|
||
|
|
|
||
|
|
/*** set up %es, (where we will load boot2 to) ***/
|
||
|
|
mov %ax, %es
|
||
|
|
|
||
|
|
#ifdef DEBUG
|
||
|
|
data32
|
||
|
|
mov $one, %esi
|
||
|
|
data32
|
||
|
|
call message
|
||
|
|
#endif
|
||
|
|
# get the boot drive id
|
||
|
|
movb $0x33, %ah
|
||
|
|
movb $0x05, %al
|
||
|
|
int $0x21
|
||
|
|
|
||
|
|
cmpb $0x80, %dl
|
||
|
|
data32
|
||
|
|
jge hd
|
||
|
|
|
||
|
|
fd:
|
||
|
|
# reset the disk system
|
||
|
|
#ifdef DEBUG
|
||
|
|
data32
|
||
|
|
mov $two, %esi
|
||
|
|
data32
|
||
|
|
call message
|
||
|
|
#endif
|
||
|
|
movb $0x0, %ah
|
||
|
|
int $0x13
|
||
|
|
data32
|
||
|
|
mov $0x0001, %ecx # cyl 0, sector 1
|
||
|
|
data32
|
||
|
|
#ifdef DEBUG
|
||
|
|
data32
|
||
|
|
mov $three, %esi
|
||
|
|
data32
|
||
|
|
call message
|
||
|
|
#endif
|
||
|
|
jmp load
|
||
|
|
|
||
|
|
hd: /**** load sector 0 into the BOOTSEG ****/
|
||
|
|
#ifdef DEBUG
|
||
|
|
data32
|
||
|
|
mov $four, %esi
|
||
|
|
data32
|
||
|
|
call message
|
||
|
|
#endif
|
||
|
|
data32
|
||
|
|
mov $0x0201, %eax
|
||
|
|
xor %ebx, %ebx # %bx = 0
|
||
|
|
data32
|
||
|
|
mov $0x0001, %ecx
|
||
|
|
#ifdef DEBUG
|
||
|
|
data32
|
||
|
|
mov $five, %esi
|
||
|
|
data32
|
||
|
|
call message
|
||
|
|
#endif
|
||
|
|
data32
|
||
|
|
andl $0xff, %edx
|
||
|
|
/*mov $0x0080, %edx*/
|
||
|
|
int $0x13
|
||
|
|
data32
|
||
|
|
jb read_error
|
||
|
|
|
||
|
|
/***# find the bootable partition *****/
|
||
|
|
data32
|
||
|
|
mov $PARTSTART, %ebx
|
||
|
|
data32
|
||
|
|
mov $NUMPART, %ecx
|
||
|
|
again:
|
||
|
|
addr16
|
||
|
|
movb %es:4(%ebx), %al
|
||
|
|
cmpb $BSDPART, %al
|
||
|
|
data32
|
||
|
|
je found
|
||
|
|
data32
|
||
|
|
add $PARTSZ, %ebx
|
||
|
|
data32
|
||
|
|
loop again
|
||
|
|
data32
|
||
|
|
mov $enoboot, %esi
|
||
|
|
data32
|
||
|
|
jmp err_stop
|
||
|
|
|
||
|
|
|
||
|
|
/*
|
||
|
|
# BIOS call "INT 0x13 Function 0x2" to read sectors from disk into memory
|
||
|
|
# Call with %ah = 0x2
|
||
|
|
# %al = number of sectors
|
||
|
|
# %ch = cylinder
|
||
|
|
# %cl = sector
|
||
|
|
# %dh = head
|
||
|
|
# %dl = drive (0x80 for hard disk, 0x0 for floppy disk)
|
||
|
|
# %es:%bx = segment:offset of buffer
|
||
|
|
# Return:
|
||
|
|
# %al = 0x0 on success; err code on failure
|
||
|
|
*/
|
||
|
|
|
||
|
|
found:
|
||
|
|
addr16
|
||
|
|
movb %es:1(%ebx), %dh /* head */
|
||
|
|
addr16
|
||
|
|
xor %ecx, %ecx
|
||
|
|
addr16
|
||
|
|
movw %es:2(%ebx), %ecx /*sect,cyl (+ 2 bytes junk in top word )*/
|
||
|
|
|
||
|
|
load:
|
||
|
|
movb $0x2, %ah /* function 2 */
|
||
|
|
movb $LOADSZ, %al /* number of blocks */
|
||
|
|
xor %ebx, %ebx /* %bx = 0, put it at 0 in the BOOTSEG */
|
||
|
|
int $0x13
|
||
|
|
data32
|
||
|
|
jb read_error
|
||
|
|
|
||
|
|
# ljmp to the second stage boot loader (boot2).
|
||
|
|
# After ljmp, %cs is BOOTSEG and boot1 (512 bytes) will be used
|
||
|
|
# as an internal buffer "intbuf".
|
||
|
|
|
||
|
|
#ifdef DEBUG
|
||
|
|
data32
|
||
|
|
mov $six, %esi
|
||
|
|
data32
|
||
|
|
call message
|
||
|
|
#endif
|
||
|
|
data32
|
||
|
|
ljmp $BOOTSEG, $EXT(boot2)
|
||
|
|
|
||
|
|
#
|
||
|
|
# read_error
|
||
|
|
#
|
||
|
|
|
||
|
|
read_error:
|
||
|
|
|
||
|
|
data32
|
||
|
|
mov $eread, %esi
|
||
|
|
err_stop:
|
||
|
|
data32
|
||
|
|
call message
|
||
|
|
data32
|
||
|
|
jmp stop
|
||
|
|
|
||
|
|
#
|
||
|
|
# message: write the error message in %ds:%esi to console
|
||
|
|
#
|
||
|
|
|
||
|
|
message:
|
||
|
|
# Use BIOS "int 10H Function 0Eh" to write character in teletype mode
|
||
|
|
# %ah = 0xe %al = character
|
||
|
|
# %bh = page %bl = foreground color (graphics modes)
|
||
|
|
|
||
|
|
data32
|
||
|
|
push %eax
|
||
|
|
data32
|
||
|
|
push %ebx
|
||
|
|
data32
|
||
|
|
mov $0x0001, %ebx
|
||
|
|
cld
|
||
|
|
|
||
|
|
nextb:
|
||
|
|
lodsb # load a byte into %al
|
||
|
|
cmpb $0x0, %al
|
||
|
|
data32
|
||
|
|
je done
|
||
|
|
movb $0xe, %ah
|
||
|
|
int $0x10 # display a byte
|
||
|
|
data32
|
||
|
|
jmp nextb
|
||
|
|
done:
|
||
|
|
data32
|
||
|
|
pop %ebx
|
||
|
|
data32
|
||
|
|
pop %eax
|
||
|
|
data32
|
||
|
|
ret
|
||
|
|
|
||
|
|
stop: hlt
|
||
|
|
data32
|
||
|
|
jmp stop # halt doesnt actually halt forever
|
||
|
|
|
||
|
|
/* error messages */
|
||
|
|
|
||
|
|
#ifdef DEBUG
|
||
|
|
one: String "1\r\n\0"
|
||
|
|
two: String "2\r\n\0"
|
||
|
|
three: String "3\r\n\0"
|
||
|
|
four: String "4\r\n\0"
|
||
|
|
five: String "5\r\n\0"
|
||
|
|
six: String "6\r\n\0"
|
||
|
|
seven: String "7\r\n\0"
|
||
|
|
#endif DEBUG
|
||
|
|
eread: String "Read error\r\n\0"
|
||
|
|
enoboot: String "No bootable partition\r\n\0"
|
||
|
|
endofcode:
|
||
|
|
/* throw in a partition in case we are block0 as well */
|
||
|
|
/* flag,head,sec,cyl,typ,ehead,esect,ecyl,start,len */
|
||
|
|
. = EXT(boot1) + PARTSTART
|
||
|
|
.byte 0x0,0,0,0,0,0,0,0
|
||
|
|
.long 0,0
|
||
|
|
.byte 0x0,0,0,0,0,0,0,0
|
||
|
|
.long 0,0
|
||
|
|
.byte 0x0,0,0,0,0,0,0,0
|
||
|
|
.long 0,0
|
||
|
|
.byte BOOTABLE,0,1,0,BSDPART,255,255,255
|
||
|
|
.long 0,50000
|
||
|
|
/* the last 2 bytes in the sector 0 contain the signature */
|
||
|
|
. = EXT(boot1) + 0x1fe
|
||
|
|
.value SIGNATURE
|
||
|
|
ENTRY(disklabel)
|
||
|
|
. = EXT(boot1) + 0x400
|