NetBSD-5.0.2/sys/arch/atari/stand/xxboot/sdboot/sdboot.S
/* $NetBSD: sdboot.S,v 1.2 2005/12/11 12:17:02 christos 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"
#ifdef __ELF__
.globl _start, main, fill
.text
_start:
#else
.globl start, main, fill
.text
start:
#endif
/*
* in: d3 ('DMAr' flag), d4 (SCSI target), d5 (boot pref), d7 (ACSI target)
*/
main: lea %pc@(regsav),%a0
movml %d3-%d5/%d7,%sp@-
movl %sp,%a0@
movw #-1,%sp@-
movw #Kbshift,%sp@-
trap #BIOS
addql #4,%sp
cmpl #0x444d4172,%d3 | SCSI bootdev?
beqs 0f
movq #-1,%d4 | no, ACSI
bras 1f
0: tstb %d5
beqs 1f | no boot preference
cmpb #0x20,%d5
bnes exit | bootpref != NetBSD
1: btst #3,%d0 | Alternate?
bnes exit
subql #1,%d0
movl %d0,%a3 | autoboot flag
movl _membot:w,%d0
lea MAXBOT,%a4
cmpl %a4,%d0
bhis exit | membot > MAXBOT
movl _memtop:w,%d0
cmpl #MINTOP,%d0
blts exit | memtop < MINTOP
andw #-4,%d0
movl %d0,%a0
movl %sp,%a0@-
movl %a0,%sp | set new stack
movq #NSEC,%d5 | sector count
movq #1,%d6 | first sector
bsrs rds0
tstl %d0
bnes 0f
/*
* loader (readsector, disklabel, autoboot)
*/
pea %a3@ | autoboot
pea %a4@(LBLST-MAXBOT) | disklabel
pea %pc@(rds1) | readsector
jsr %a4@(BXXST-MAXBOT)
lea %sp@(12),%sp | NetBSD not booted
0: movl %sp@,%sp | restore BIOS stack
tstl %d0
bmis exit
movl %d0,%sp@(8) | new boot preference
exit: movml %sp@+,%d3-%d5/%d7
rts
/*
* int readsec (void *buffer, u_int offset, u_int count);
*/
rds1: movml %d2-%d7/%a2-%a6,%sp@-
movl %pc@(regsav),%a0
movml %a0@,%d3-%d5/%d7
movl %sp@(48),%a4 | buffer
movl %sp@(52),%d6 | offset
movl %sp@(56),%d3 | count
0: movl #255,%d5
cmpl %d5,%d3
bccs 1f
movl %d3,%d5
1: bsrs rds0
tstl %d0
bnes 2f
addl #(255*512),%a4
addl %d5,%d6
subl %d5,%d3
bnes 0b
2: movml %sp@+,%d2-%d7/%a2-%a6
rts
/*
* in: d4/d7 (target) d5 (count), d6 (offset), a4 (buffer)
* out: d0 (<= 0)
* mod: d0, d1, d2, a0, a5, a6
*/
rds0: tstl %d4
bmis 0f
movw %d4,%sp@- | device
pea %a4@ | buffer
movw %d5,%sp@- | count
movl %d6,%sp@- | offset
movw #DMAread,%sp@-
trap #XBIOS
lea %sp@(14),%sp
rts
0: st flock:w
movl _hz_200:w,%d0
addql #2,%d0
1: cmpl _hz_200:w,%d0
bccs 1b
movml %d6/%a4,%sp@-
lea dmahi:w,%a6
movb %sp@(7),%a6@(4)
movb %sp@(6),%a6@(2)
movb %sp@(5),%a6@
lea %pc@(r0com),%a6
movb %sp@(1),%a6@(1)
movb %sp@(2),%a6@(5)
movb %sp@(3),%a6@(9)
movb %d5,%a6@(13)
addql #8,%sp
lea dmodus:w,%a6
lea daccess:w,%a5
movw #0x198,%a6@
movw #0x098,%a6@
movw %d5,%a5@
movw #0x88,%a6@
movq #0,%d0
movb %d7,%d0
orb #0x08,%d0
swap %d0
movw #0x8a,%d0
bsrs shake
lea %pc@(r0com),%a0
movq #3,%d2
2: movl %a0@+,%d0
bsrs shake
dbra %d2,2b
movq #0x0a,%d0
movl %d0,%a5@
movl #0x190,%d1
bsrs wait
movw #0x8a,%a6@
movw %a5@,%d0
andw #0xff,%d0
beqs 0f
r0err: movq #-1,%d0
0: movw #0x80,%a6@
clrb flock:w
r0ret: rts
shake: movl %d0,%a5@
movq #0x0a,%d1
wait: addl _hz_200:w,%d1
0: btst #5,gpip:w
beqs r0ret
cmpl _hz_200:w,%d1
bccs 0b
addql #4,%sp
bras r0err
r0com: .long 0x0000008a
.long 0x0000008a
.long 0x0000008a
.long 0x0001008a
regsav: .long 0
fill: .space 24
.ascii "NetBSD"
hd_siz: .long 0
p0_dsc: .long 0, 0, 0
p1_dsc: .long 0, 0, 0
p2_dsc: .long 0, 0, 0
p3_dsc: .long 0, 0, 0
bsl_st: .long 0
bsl_sz: .long 0
.word 0
end: