NetBSD/sys/arch/atari/stand/xxboot/fdboot/fdboot.s
leo aae827a845 - The Hades bios does not pass a 'bootpreference' in d5. Deal with it by
getting the 'bootpreference' ourselves when it is not set to any legal
  value.
- Because the relation between memtop/membot and the video base does not
  hold on the Hades, skip testing on it.
1996-12-28 23:37:53 +00:00

224 lines
4.8 KiB
ArmAsm

/* $NetBSD: fdboot.s,v 1.3 1996/12/28 23:38:06 leo Exp $ */
/*
* Copyright (c) 1995 Waldi Ravens.
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by Waldi Ravens.
* 4. The name of the author may not be used to endorse or promote products
* derived from this software without specific prior written permission
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#include "xxboot.h"
.globl start, main, fill, end
.text
start: bras main
/*
* Fake gemdos-fs bootsector, to keep TOS away.
*/
.ascii "NetBSD" | oem
.byte 0,0,0 | serial
.word 0 | bps
.byte 0 | spc
.word 0 | res
.byte 0 | fat
.word 0 | ndirs
.word 0 | sec
.byte 0 | media
.word 0 | spf
.word 0 | spt
.word 0 | side
.word 0 | hid
.even
/*
* ROM loader does not save any register!
*/
main: movml d1-d7/a0-a6,sp@-
lea pc@(m_bot),a3
movl _membot:w,d3
lea MAXBOT,a6
cmpl a6,d3
bhis exit | membot > MAXBOT
lea pc@(m_top),a3
movl _memtop:w,d3
cmpl #MINTOP,d3
blts exit | memtop < MINTOP
andw #-4,d3
movl d3,a0
movl sp,a0@-
movl a0,sp | set new stack
/*
* Determine the number of sectors per cylinder.
*/
movq #0,d3
0: movl a6,a3 | buffer
movq #1,d0 | count
movq #0,d1 | side
movl d1,d2 | track
addw d0,d3 | sector
bsr rds0
beqs 0b
subqw #1,d3
addw d3,d3
lea pc@(secpercyl),a0
movw d3,a0@
/*
* Load secondary boot loader and disklabel.
*/
movq #NSEC,d5 | # of sectors
movq #1,d4 | first sector
movl a6,a3 | load address
bsr rds1
lea pc@(m_rds),a3
bnes 0f | I/O error
/*
* int bootxx(readsector, disklabel, autoboot)
*/
clrl sp@- | no autoboot
pea a6@(LBLST-MAXBOT) | disklabel
pea pc@(rds2) | readsector
jsr a6@(BXXST-MAXBOT)
lea pc@(m_sbl),a3 | NetBSD not booted
lea sp@(12),sp
0: movl sp@,sp | restore BIOS stack
movl d0,d3
exit: bsrs puts | display error
lea pc@(m_key),a3
bsrs puts | wait for key
0: movml sp@+,d1-d7/a0-a6
movq #0,d0
rts
/*
* puts (in: a3, d3)
*/
0: cmpw #35,d0 | '#'
bnes 1f
bsrs puti
bras puts
1: cmpw #64,d0 | '@'
bnes 2f
movw #2,sp@-
movw #Bconin,sp@-
trap #BIOS
addql #4,sp
bras puts
2: bsrs putc
puts: movq #0,d0
movb a3@+,d0
bnes 0b
rts
puti: swap d3
bsrs 0f
swap d3
0: rorw #8,d3
bsrs 1f
rorw #8,d3
1: rorb #4,d3
bsrs 2f
rorb #4,d3
2: movw d3,d0
andw #15,d0
addw #48,d0
cmpw #58,d0
bcss putc
addw #39,d0
putc: movw d0,sp@-
movw #2,sp@-
movw #Bconout,sp@-
trap #BIOS
addql #6,sp
rts
/*
* int readsec (void *buffer, u_int offset, u_int count);
*/
rds2: movml d2-d5/a2-a3,sp@-
movl sp@(28),a3 | buffer
movl sp@(32),d4 | offset
movl sp@(36),d5 | count
bsrs rds1
movml sp@+,d2-d5/a2-a3
rts
rds1: bsrs 1f
bnes 0f
tstl d5
bnes rds1
0: rts
1: movq #0,d0
movw pc@(secpercyl),d0
movl d4,d3
divuw d0,d3
movw d3,d2 | track
clrw d3
swap d3
lsrw #1,d0
divuw d0,d3
movw d3,d1 | side
swap d3
subw d3,d0
addqw #1,d3 | sector
cmpl d0,d5
bccs rds0
movw d5,d0
rds0: movw d0,sp@- | count
movw d1,sp@- | side
movw d2,sp@- | track
movw d3,sp@- | sector
movw _bootdev:w,sp@- | device
clrl sp@- | filler
movl a3,sp@- | buffer
addl d0,d4
subl d0,d5
lsll #8,d0
addl d0,d0
addl d0,a3
movw #Floprd,sp@-
trap #XBIOS
lea sp@(20),sp
tstl d0
rts
secpercyl:
.word 0
m_bot: .asciz "fdboot: membot == 0x#\r\n"
m_top: .asciz "fdboot: memtop == 0x#\r\n"
m_sbl: .asciz "fdboot: bootxx => 0x#\r\n"
m_rds: .asciz "fdboot: Floprd => 0x#\r\n"
m_key: .asciz "\007\r\npress any key... @\r\n"
fill: .space 22 | 510-(fill-start)
.word 0 | checksum
end: