xref: /netbsd-src/sys/arch/atari/stand/xxboot/ahdi-wdb00t/wdb00t.ahdi.S (revision 4ac76180e904e771b9d522c7e57296d371f06499)
1/*	$NetBSD: wdb00t.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	movb	%d5,%d1			| NVRAM bootpref
54	bnes	0f
55
56	| The Hades bios does not provide a bootprev. In case
57	| of doubt, we fetch it ourselves.
58	movb	#BOOTPREF,rtcrnr:w
59	movb	rtcdat:w,%d1
60	bnes	0f
61	movq	#-8,%d1	 		| bootpref = any
62
630:	movb	%a0@,%d2			| bootflags
64	btst	#0,%d2
65	beqs	1f
66	andb	%d1,%d2
67	bnes	boot
681:	lea	%a0@(12),%a0
69	dbra	%d0,0b
70
71exit:	movml	%sp@+,%d3/%d5
72tostst:	clrw	_bootdev:w
73	movl	_sysbase:w,%a0
74	movl	%a0@(24),%d0
75	swap	%d0
76	cmpl	#0x19870422,%d0		| old TOS?
77	bccs	0f			| no
78	movw	#0xe0,%d7
790:	rts
80
81boot:	movl	%a0@(4),%d6
82	movq	#1,%d5
83	lea	%pc@(end),%a4
84	bsrs	rds0
85	tstw	%d0
86	bnes	exit
87	movl	%a4,%a0
88	movw	#0xff,%d0
89	movq	#0,%d1
900:	addw	%a0@+,%d1
91	dbra	%d0,0b
92	cmpw	#0x1234,%d1
93	bnes	exit
94	lea	%pc@(rds0),%a3
95	lea	%pc@(tostst),%a5
96	movml	%sp@+,%d3/%d5
97	jmp	%a4@			| start bootsector code
98/*
99 * in:  d4 (target) d5 (count), d6 (offset), a4 (buffer)
100 * out: d0 (<= 0)
101 * mod: d0, d1, d2, a0, a1, a5, a6
102 */
103rds0:	lea	%pc@(dpar),%a6
104	tstb	%a6@
105	bnes	0f
106	movb	%d4,%d0
107	andb	#1,%d0
108	aslb	#4,%d0
109	orb	#0xa0,%d0
110	movb	%d0,idesdh:l
111	movl	%a4,%a0
112	movq	#0,%d1
113	movb	#0,idedor:l
114	movb	#0xec,idecr:l		| IDENTIFY DRIVE
115	bsrs	wait
116	bnes	err
117	movb	%a4@(7),%a6@		| tracks/cylinder
118	movb	%a4@(13),%a6@(1)		| sectors/track
1190:	movl	%d6,%d1
120	movq	#0,%d0
121	movb	%a6@(1),%d0
122	movq	#0,%d2
123	movb	%a6@,%d2
124	mulu	%d0,%d2
125	divu	%d2,%d1
126	movb	%d1,idecl:l
127	lsrl	#8,%d1
128	movb	%d1,idech:l
129	lsrl	#8,%d1
130	divu	%d0,%d1
131	movb	%d4,%d0
132	andb	#1,%d0
133	aslb	#4,%d0
134	orb	%d0,%d1
135	orb	#0xa0,%d1
136	movb	%d1,idesdh:l
137	swap	%d1
138	addqw	#1,%d1
139	movb	%d1,idesn:l
140	movl	%a4,%a0
141	movb	%d5,idesc:l
142	movw	%d5,%d1
143	subqw	#1,%d1
144	movb	#0,idedor:l
145	movb	#0x20,idecr:l
146wait:	movl	#0x7d0,%d0
147	addl	_hz_200:w,%d0
1482:	btst	#5,gpip:w
149	beqs	3f
150	cmpl	_hz_200:w,%d0
151	bhis	2b
152err:	movq	#-1,%d0
153	rts
1543:	movb	idesr:l,%d0
155	btst	#0,%d0
156	bnes	err
157	btst	#3,%d0
158	beqs	err
159	movq	#63,%d0
160	lea	idedr:l,%a1
1614:	movw	%a1@,%a0@+
162	movw	%a1@,%a0@+
163	movw	%a1@,%a0@+
164	movw	%a1@,%a0@+
165	dbra	%d0,4b
166	dbra	%d1,wait
167	movq	#0,%d0
168	rts
169
170fill:	.space	52
171
172dpar:	.byte	0			| tracks/cylinder
173	.byte	0			| sectors/track
174	.ascii	"NetBSD"
175hd_siz:	.long	0
176p0_dsc:	.long	0, 0, 0
177p1_dsc:	.long	0, 0, 0
178p2_dsc:	.long	0, 0, 0
179p3_dsc:	.long	0, 0, 0
180bsl_st:	.long	0
181bsl_sz:	.long	0
182	.word	0
183end:
184