xref: /netbsd-src/sys/arch/atari/stand/xxboot/ahdi-sdb00t/sdb00t.ahdi.S (revision ae23d92f756cf01807af054d2355aad95e40a856)
1/*	$NetBSD: sdb00t.ahdi.S,v 1.3 2022/06/26 14:14:46 tsutsui Exp $	*/
2
3/*
4 * Copyright (c) 1995 Waldi Ravens
5 * All rights reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 * 1. Redistributions of source code must retain the above copyright
11 *    notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 *    notice, this list of conditions and the following disclaimer in the
14 *    documentation and/or other materials provided with the distribution.
15 * 3. All advertising materials mentioning features or use of this software
16 *    must display the following acknowledgement:
17 *        This product includes software developed by Waldi Ravens.
18 * 4. The name of the author may not be used to endorse or promote products
19 *    derived from this software without specific prior written permission
20 *
21 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
22 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
23 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
24 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
25 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
26 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
27 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
28 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
29 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
30 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
31 */
32
33#include "xxboot.h"
34
35	.globl	_start, main, fill
36
37	.text
38
39_start:	bras	main
40	bra	rds0
41
42main:	bclr	#2,(_drvbits+3):w
43	clrl	pun_ptr:w
44	movml	%d3/%d5,%sp@-
45	movw	#-1,%sp@-
46	movw	#Kbshift,%sp@-
47	trap	#BIOS
48	addql	#4,%sp
49	btst	#3,%d0			| Alternate?
50	bnes	exit
51	movq	#3,%d0
52	lea	%pc@(p0_dsc),%a0
53	cmpl	#0x444d4172,%d3		| SCSI bootdev?
54	beqs	0f
55	movq	#-1,%d4			| no, ACSI
56	movq	#0,%d5
570:	movb	%d5,%d1			| NVRAM bootpref
58	bnes	1f
59
60	| The Hades bios does not provide a bootprev. In case
61	| of doubt, we fetch it ourselves.
62 	moveml	%d0-%d2/%a0-%a2,%sp@-
63 	pea	bpref
64 	movw	#1, %sp@-
65 	movw	#1, %sp@-
66 	movw	#0, %sp@-
67 	movw	#NVMaccess, %sp@-
68 	trap	#XBIOS
69 	lea	%sp@(12),%sp
70 	moveml	%sp@+,%d0-%d2/%a0-%a2
71 	movb	bpref:w,%d1
72	bnes	1f
73	movq	#-8,%d1	 		| bootpref = any
74
751:	movb	%a0@,%d2			| bootflags
76	btst	#0,%d2
77	beqs	2f
78	andb	%d1,%d2
79	bnes	boot
802:	lea	%a0@(12),%a0
81	dbra	%d0,1b
82
83exit:	movml	%sp@+,%d3/%d5
84tostst:	clrw	_bootdev:w
85	movl	_sysbase:w,%a0
86	movl	%a0@(24),%d0
87	swap	%d0
88	cmpl	#0x19870422,%d0		| old TOS?
89	bccs	0f			| no
90	movw	#0xe0,%d7
910:	rts
92
93boot:	movl	%a0@(4),%d6
94	movq	#1,%d5
95	lea	%pc@(end),%a4
96	bsrs	rds0
97	tstw	%d0
98	bnes	exit
99	movl	%a4,%a0
100	movw	#0xff,%d0
101	movq	#0,%d1
1020:	addw	%a0@+,%d1
103	dbra	%d0,0b
104	cmpw	#0x1234,%d1
105	bnes	exit
106	lea	%pc@(rds0),%a3
107	lea	%pc@(tostst),%a5
108	movml	%sp@+,%d3/%d5
109	jmp	%a4@			| start bootsector code
110/*
111 * in:  d4/d7 (target) d5 (count), d6 (offset), a4 (buffer)
112 * out: d0 (<= 0)
113 * mod: d0, d1, d2, a0, a1, a5, a6
114 */
115rds0:	tstl	%d4
116	bmis	0f
117	movw	%d4,%sp@-			| device
118	pea	%a4@			| buffer
119	movw	%d5,%sp@-			| count
120	movl	%d6,%sp@-			| offset
121	movw	#DMAread,%sp@-
122	trap	#XBIOS
123	lea	%sp@(14),%sp
124	rts
125
1260:	st	flock:w
127	movl	_hz_200:w,%d0
128	addql	#2,%d0
1291:	cmpl	_hz_200:w,%d0
130	bccs	1b
131	movml	%d6/%a4,%sp@-
132	lea	dmahi:w,%a6
133	movb	%sp@(7),%a6@(4)
134	movb	%sp@(6),%a6@(2)
135	movb	%sp@(5),%a6@
136	lea	%pc@(r0com),%a6
137	movb	%sp@(1),%a6@(1)
138	movb	%sp@(2),%a6@(5)
139	movb	%sp@(3),%a6@(9)
140	movb	%d5,%a6@(13)
141	addql	#8,%sp
142	lea	dmodus:w,%a6
143	lea	daccess:w,%a5
144	movw	#0x198,%a6@
145	movw	#0x098,%a6@
146	movw	%d5,%a5@
147	movw	#0x88,%a6@
148	movq	#0,%d0
149	movb	%d7,%d0
150	orb	#0x08,%d0
151	swap	%d0
152	movw	#0x8a,%d0
153	bsrs	shake
154	lea	%pc@(r0com),%a0
155	movq	#3,%d2
1562:	movl	%a0@+,%d0
157	bsrs	shake
158	dbra	%d2,2b
159	movq	#0x0a,%d0
160	movl	%d0,%a5@
161	movl	#0x190,%d1
162	bsrs	wait
163	movw	#0x8a,%a6@
164	movw	%a5@,%d0
165	andw	#0xff,%d0
166	beqs	0f
167r0err:	movq	#-1,%d0
1680:	movw	#0x80,%a6@
169	clrb	flock:w
170r0ret:	rts
171
172shake:	movl	%d0,%a5@
173	movq	#0x0a,%d1
174wait:	addl	_hz_200:w,%d1
1750:	btst	#5,gpip:w
176	beqs	r0ret
177	cmpl	_hz_200:w,%d1
178	bccs	0b
179	addql	#4,%sp
180	bras	r0err
181
182r0com:	.long	0x0000008a
183	.long	0x0000008a
184	.long	0x0000008a
185	.long	0x0001008a
186bpref:	.word	0
187
188fill:	.space	16
189
190	.ascii	"NetBSD"
191hd_siz:	.long	0
192p0_dsc:	.long	0, 0, 0
193p1_dsc:	.long	0, 0, 0
194p2_dsc:	.long	0, 0, 0
195p3_dsc:	.long	0, 0, 0
196bsl_st:	.long	0
197bsl_sz:	.long	0
198	.word	0
199end:
200