NetBSD/sys/arch/atari/stand/xxboot/sdboot/sdboot.s

215 lines
4.6 KiB
ArmAsm

/* $NetBSD: sdboot.s,v 1.3 1996/12/28 23:38:07 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
/*
* in: d3 ('DMAr' flag), d4 (SCSI target), d5 (boot pref), d7 (ACSI target)
*/
start:
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: