pbr.S revision 1.2 1 1.2 nonaka /* $NetBSD: pbr.S,v 1.2 2012/01/21 19:44:30 nonaka Exp $ */
2 1.1 uwe
3 1.1 uwe /*-
4 1.2 nonaka * Copyright (C) 2005 NONAKA Kimihiro <nonaka (at) netbsd.org>
5 1.1 uwe * All rights reserved.
6 1.1 uwe *
7 1.1 uwe * Redistribution and use in source and binary forms, with or without
8 1.1 uwe * modification, are permitted provided that the following conditions
9 1.1 uwe * are met:
10 1.1 uwe * 1. Redistributions of source code must retain the above copyright
11 1.1 uwe * notice, this list of conditions and the following disclaimer.
12 1.1 uwe * 2. Redistributions in binary form must reproduce the above copyright
13 1.1 uwe * notice, this list of conditions and the following disclaimer in the
14 1.1 uwe * documentation and/or other materials provided with the distribution.
15 1.1 uwe *
16 1.2 nonaka * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
17 1.2 nonaka * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
18 1.2 nonaka * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
19 1.2 nonaka * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
20 1.2 nonaka * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
21 1.2 nonaka * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
22 1.2 nonaka * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
23 1.2 nonaka * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
24 1.2 nonaka * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
25 1.2 nonaka * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
26 1.1 uwe */
27 1.1 uwe
28 1.1 uwe #include <machine/asm.h>
29 1.1 uwe #include <sys/bootblock.h>
30 1.1 uwe
31 1.1 uwe #ifdef BOOT_FROM_FAT
32 1.1 uwe #define MBR_AFTERBPB 90 /* BPB size in FAT32 partition BR */
33 1.1 uwe #else
34 1.1 uwe #define MBR_AFTERBPB 62 /* BPB size in floppy master BR */
35 1.1 uwe #endif
36 1.1 uwe
37 1.1 uwe ENTRY(start)
38 1.1 uwe bra start0
39 1.1 uwe .byte 0x11 /* 0x4e11: cmp/pz r14... */
40 1.1 uwe .ascii "NetBSD20"
41 1.1 uwe
42 1.1 uwe . = _C_LABEL(start) + MBR_BPB_OFFSET /* move to start of BPB */
43 1.1 uwe
44 1.1 uwe . = _C_LABEL(start) + MBR_AFTERBPB /* skip BPB */
45 1.1 uwe start0:
46 1.1 uwe mova mbr_end, r0
47 1.1 uwe mov.w mbr_size, r2
48 1.1 uwe sub r2, r0
49 1.1 uwe mov r0, r11 /* r11: own loaded address */
50 1.1 uwe
51 1.1 uwe mov.w stack_offset, r1
52 1.1 uwe add r1, r0
53 1.1 uwe mov r0, r15 /* r15: stack pointer */
54 1.1 uwe mov r0, r10 /* r10: load address */
55 1.1 uwe
56 1.1 uwe /* enable/flush cache */
57 1.1 uwe mov #0, r4
58 1.1 uwe mov #6, r0
59 1.1 uwe trapa #0x3f
60 1.1 uwe
61 1.1 uwe /* Read from start of disk */
62 1.1 uwe mov #0x40, r4 /* LBA */
63 1.1 uwe mov #0, r5 /* LBA #0 */
64 1.1 uwe mov r10, r6 /* buffer address */
65 1.1 uwe bsr read_sectors_lba
66 1.1 uwe mov #BOOTXX_SECTORS, r7 /* number of sectors */
67 1.1 uwe
68 1.1 uwe mov.l @r11, r1
69 1.1 uwe mov.l @r10, r2
70 1.1 uwe cmp/eq r1, r2
71 1.1 uwe bt/s pbr_read_ok
72 1.1 uwe mov #0, r9 /* r9: sector # */
73 1.1 uwe
74 1.1 uwe /* Search bootable partition */
75 1.1 uwe mov.w part_offset, r12
76 1.1 uwe add r10, r12 /* r12: pointer to partition entry */
77 1.1 uwe mov #MBR_PART_COUNT, r8 /* r8: partition loop counter */
78 1.1 uwe loop_part:
79 1.1 uwe mov.b @(4, r12), r0
80 1.1 uwe #ifdef BOOT_FROM_FAT
81 1.1 uwe cmp/eq #MBR_PTYPE_FAT12, r0
82 1.1 uwe bt found
83 1.1 uwe cmp/eq #MBR_PTYPE_FAT16S, r0
84 1.1 uwe bt found
85 1.1 uwe cmp/eq #MBR_PTYPE_FAT16B, r0
86 1.1 uwe bt found
87 1.1 uwe cmp/eq #MBR_PTYPE_FAT32, r0
88 1.1 uwe bt found
89 1.1 uwe cmp/eq #MBR_PTYPE_FAT32L, r0
90 1.1 uwe bt found
91 1.1 uwe cmp/eq #MBR_PTYPE_FAT16L, r0
92 1.1 uwe bt found
93 1.1 uwe #else
94 1.1 uwe cmp/eq #MBR_PTYPE_NETBSD, r0
95 1.1 uwe #endif
96 1.1 uwe bf next_part
97 1.1 uwe
98 1.1 uwe found:
99 1.1 uwe /* found boot partition */
100 1.1 uwe mov.w @(8, r12), r0
101 1.1 uwe mov r0, r1
102 1.1 uwe mov.w @(10, r12), r0
103 1.1 uwe extu.w r1, r1
104 1.1 uwe shll16 r0
105 1.1 uwe or r1, r0
106 1.1 uwe tst r0, r0
107 1.1 uwe bt next_part /* start LBA == 0 ? */
108 1.1 uwe
109 1.1 uwe bra boot_lba
110 1.1 uwe mov r0, r9
111 1.1 uwe
112 1.1 uwe next_part:
113 1.1 uwe dt r8
114 1.1 uwe bf/s loop_part
115 1.1 uwe add #16, r12
116 1.1 uwe
117 1.1 uwe ptn_error:
118 1.1 uwe /* Not found NetBSD partition */
119 1.1 uwe mova ERR_PTN, r0
120 1.1 uwe error:
121 1.1 uwe bsr message_crlf
122 1.1 uwe mov r0, r4
123 1.1 uwe 99: bra 99b
124 1.1 uwe nop
125 1.1 uwe
126 1.1 uwe read_error:
127 1.1 uwe bra error
128 1.1 uwe mova ERR_READ, r0
129 1.1 uwe
130 1.1 uwe magic_error:
131 1.1 uwe bra error
132 1.1 uwe mova ERR_NO_BOOTXX, r0
133 1.1 uwe
134 1.1 uwe message_crlf:
135 1.1 uwe mov #32, r0
136 1.1 uwe trapa #0x3f
137 1.1 uwe mova crlf, r0
138 1.1 uwe mov r0, r4
139 1.1 uwe mov #32, r0
140 1.1 uwe trapa #0x3f
141 1.1 uwe rts
142 1.1 uwe nop
143 1.1 uwe
144 1.1 uwe read_sectors_lba:
145 1.1 uwe mov #2, r0
146 1.1 uwe trapa #0x3f
147 1.1 uwe tst r0, r0
148 1.1 uwe bf read_error
149 1.1 uwe rts
150 1.1 uwe nop
151 1.1 uwe
152 1.1 uwe boot_lba:
153 1.1 uwe mov #0x40, r4 /* LBA */
154 1.1 uwe mov r9, r5 /* LBA # */
155 1.1 uwe mov r10, r6 /* buffer address */
156 1.1 uwe bsr read_sectors_lba
157 1.1 uwe mov #BOOTXX_SECTORS, r7 /* number of sectors */
158 1.1 uwe
159 1.1 uwe pbr_read_ok:
160 1.1 uwe mov.l .L.bootxx_magic1, r1
161 1.1 uwe mov.l .L.bootxx_magic, r2
162 1.1 uwe mov.l @r2, r2
163 1.1 uwe cmp/eq r1, r2
164 1.1 uwe bf magic_error
165 1.1 uwe
166 1.1 uwe /* flush cache */
167 1.1 uwe mov #0, r4
168 1.1 uwe mov #6, r0
169 1.1 uwe trapa #0x3f
170 1.1 uwe
171 1.1 uwe mov.l .L.bootxx_start, r13
172 1.1 uwe jmp @r13 /* jump to bootxx */
173 1.1 uwe mov r9, r4 /* pass sector address to bootxx */
174 1.1 uwe
175 1.1 uwe
176 1.1 uwe .align 1
177 1.1 uwe mbr_size: .word mbr_end - _C_LABEL(start)
178 1.1 uwe .align 1
179 1.1 uwe stack_offset: .word 0x1000
180 1.1 uwe .align 1
181 1.1 uwe part_offset: .word MBR_PART_OFFSET
182 1.1 uwe .align 1
183 1.1 uwe magic_offset: .word MBR_MAGIC_OFFSET
184 1.1 uwe
185 1.1 uwe .align 2
186 1.1 uwe .L.bootxx_magic1:
187 1.1 uwe .long LANDISK_BOOT_MAGIC_1
188 1.1 uwe .L.bootxx_magic:
189 1.1 uwe .long _C_LABEL(bootxx_magic)
190 1.1 uwe .L.bootxx_start:
191 1.1 uwe .long _C_LABEL(bootxx_start)
192 1.1 uwe
193 1.1 uwe .align 2
194 1.1 uwe crlf: .asciz "\r\n"
195 1.1 uwe
196 1.1 uwe .align 2
197 1.1 uwe ERR_READ: .asciz "Disk read"
198 1.1 uwe .align 2
199 1.1 uwe ERR_NO_BOOTXX: .asciz "Not a bootxx image"
200 1.1 uwe .align 2
201 1.1 uwe ERR_PTN: .asciz "No NetBSD partition"
202 1.1 uwe
203 1.1 uwe
204 1.1 uwe /* space for mbr_dsn */
205 1.1 uwe . = _C_LABEL(start) + MBR_DSN_OFFSET
206 1.1 uwe .long 0
207 1.1 uwe
208 1.1 uwe /* mbr_bootsel_magic */
209 1.1 uwe . = _C_LABEL(start) + MBR_BS_MAGIC_OFFSET
210 1.1 uwe .word 0
211 1.1 uwe
212 1.1 uwe /*
213 1.1 uwe * MBR partition table
214 1.1 uwe */
215 1.1 uwe . = _C_LABEL(start) + MBR_PART_OFFSET
216 1.1 uwe _pbr_part0:
217 1.1 uwe .byte 0, 0, 0, 0, 0, 0, 0, 0
218 1.1 uwe .byte 0, 0, 0, 0, 0, 0, 0, 0
219 1.1 uwe _pbr_part1:
220 1.1 uwe .byte 0, 0, 0, 0, 0, 0, 0, 0
221 1.1 uwe .byte 0, 0, 0, 0, 0, 0, 0, 0
222 1.1 uwe _pbr_part2:
223 1.1 uwe .byte 0, 0, 0, 0, 0, 0, 0, 0
224 1.1 uwe .byte 0, 0, 0, 0, 0, 0, 0, 0
225 1.1 uwe _pbr_part3:
226 1.1 uwe .byte 0, 0, 0, 0, 0, 0, 0, 0
227 1.1 uwe .byte 0, 0, 0, 0, 0, 0, 0, 0
228 1.1 uwe
229 1.1 uwe . = _C_LABEL(start) + MBR_MAGIC_OFFSET
230 1.1 uwe magic:
231 1.1 uwe .word MBR_MAGIC
232 1.1 uwe mbr_end:
233