1/*	$NetBSD: xxboot.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/*
41 * Fake gemdos-fs bootsector, to keep TOS away.
42 */
43	.ascii	"NetBSD"	| oem
44	.byte	0,0,0		| serial
45	.word	0		| bps
46	.byte	0		| spc
47	.word	0		| res
48	.byte	0		| fat
49	.word	0		| ndirs
50	.word	0		| sec
51	.byte	0		| media
52	.word	0		| spf
53	.word	0		| spt
54	.word	0		| side
55	.word	0		| hid
56	.even
57/*
58 * AHDI rootsector code passes:
59 * d3: SCSI/IDE <-> ACSI flag	d4: SCSI/IDE target (or -1)
60 * d5: boot preference		d6: offset of boot block
61 * d7: ACSI target		a3: pointer to readsector()
62 * a4: pointer to `start'	a5: pointer to back-to-ROM
63 */
64main:	movml	%d3-%d7/%a3-%a5,%sp@-
65	lea	%pc@(regsav),%a0
66	movl	%sp,%a0@
67
68	movw	#-1,%sp@-
69	movw	#Kbshift,%sp@-
70	trap	#BIOS
71	addql	#4,%sp
72	subql	#1,%d0
73	movl	%d0,%a5			| autoboot flag
74
75	lea	%pc@(m_bot),%a6
76	movl	_membot:w,%d3
77	lea	MAXBOT,%a4
78	cmpl	%a4,%d3
79	bhis	exit			| membot > MAXBOT
80
81	lea	%pc@(m_top),%a6
82	movl	_memtop:w,%d3
83	cmpl	#MINTOP,%d3
84	blts	exit			| memtop < MINTOP
85
86	andw	#-4,%d3
87	movl	%d3,%a0
88	movl	%sp,%a0@-
89	movl	%a0,%sp			| set new stack
90/*
91 * Load secondary boot loader and disklabel.
92 */
93	movml	%a4/%a5,%sp@-
94	movq	#NSEC,%d3		| # of sectors
95	addql	#1,%d6			| first sector
96	bsr	rds1
97	lea	%pc@(m_rds),%a6
98	movml	%sp@+,%a4/%a5
99	bnes	0f			| I/O error
100/*
101 * int bootxx(readsector, disklabel, autoboot)
102 */
103	pea	%a5@			| autoboot
104	pea	%a4@(LBLST-MAXBOT)	| disklabel
105	pea	%pc@(rds2)		| readsector
106	jsr	%a4@(BXXST-MAXBOT)
107	lea	%pc@(m_sbl),%a6		| NetBSD not booted
108	lea	%sp@(12),%sp
109
1100:	movl	%sp@,%sp			| restore BIOS stack
111	movl	%d0,%d3
112	bmis	exit
113	movml	%sp@+,%d3-%d7/%a3-%a5
114	movl	%d0,%d5			| new boot preference
115	jmp	%a4@(-0x200)
116
117exit:	bsrs	puts			| display error
118	lea	%pc@(m_key),%a6
119	bsrs	puts			| wait for key
120	movml	%sp@+,%d3-%d7/%a3-%a5
121	jmp	%a5@
122
123/*
124 * puts (in: a6, d3)
125 */
1260:	cmpw	#35,%d0		| '#'
127	bnes	1f
128	bsrs	puti
129	bras	puts
1301:	cmpw	#64,%d0		| '@'
131	bnes	2f
132	movw	#2,%sp@-
133	movw	#Bconin,%sp@-
134	trap	#BIOS
135	addql	#4,%sp
136	bras	puts
1372:	bsrs	putc
138puts:	movq	#0,%d0
139	movb	%a6@+,%d0
140	bnes	0b
141	rts
142
143puti:	swap	%d3
144	bsrs	0f
145	swap	%d3
1460:	rorw	#8,%d3
147	bsrs	1f
148	rorw	#8,%d3
1491:	rorb	#4,%d3
150	bsrs	2f
151	rorb	#4,%d3
1522:	movw	%d3,%d0
153	andw	#15,%d0
154	addw	#48,%d0
155	cmpw	#58,%d0
156	bcss	putc
157	addw	#39,%d0
158putc:	movw	%d0,%sp@-
159	movw	#2,%sp@-
160	movw	#Bconout,%sp@-
161	trap	#BIOS
162	addql	#6,%sp
163	rts
164/*
165 * int readsec (void *buffer, u_int offset, u_int count);
166 */
167rds2:	movml	%d2-%d7/%a2-%a6,%sp@-
168	movl	%pc@(regsav),%a0
169	movml	%a0@,%d3-%d7/%a3-%a5
170	movl	%sp@(48),%a4		| buffer
171	movl	%sp@(52),%d6		| offset
172	movl	%sp@(56),%d3		| count
173	bsrs	rds1
174	movml	%sp@+,%d2-%d7/%a2-%a6
175	rts
176
177rds1:	movl	#255,%d5
178	cmpl	%d5,%d3
179	bccs	0f
180	movl	%d3,%d5
1810:	jsr	%a3@
182	tstl	%d0
183	bnes	1f
184	addl	#(255*512),%a4
185	addl	%d5,%d6
186	subl	%d5,%d3
187	bnes	rds1
1881:	rts
189
190m_bot:	.asciz	"xxboot: membot == 0x#\r\n"
191m_top:	.asciz	"xxboot: memtop == 0x#\r\n"
192m_sbl:	.asciz	"xxboot: bootxx => 0x#\r\n"
193m_rds:	.asciz	"xxboot: Floprd => 0x#\r\n"
194m_key:	.asciz	"\007\r\npress any key... @\r\n"
195
196regsav:	.long	0
197
198fill:	.space	54		| 510-(fill-start)
199	.word	0		| checksum
200end:
201