1 #include <u.h>
2 #include <libc.h>
3 #include <bio.h>
4 #include <libsec.h>
5
6 #include "iso9660.h"
7
8 /* FreeBSD 4.5 installation CD for reference
9 g% cdsector 17 | xd -b
10 1+0 records in
11 1+0 records out
12 0000000 00 - volume descriptor type (0)
13 43 44 30 30 31 - "CD001"
14 01 - volume descriptor version (1)
15 45 4c 20 54 4f 52 49 54 4f
16 0000010 20 53 50 45 43 49 46 49 43 41 54 49 4f 4e 00 00
17 0000020 00 00 00 00 00 00 00 - 7-39 boot system identifier
18 "EL TORITO SPECIFICATION"
19
20 00 00 00 00 00 00 00 00 00
21 0000030 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
22 0000040 00 00 00 00 00 00 00 - 39-71 boot identifier
23
24 boot system use:
25
26 absolute pointer to the boot catalog??
27
28 4d 0c 00 00 00 00 00 00 00
29 0000050 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
30 0000580 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
31 0000590 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
32 00005a0 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
33 g% cdsector 3149 | xd -b # 0x0c4d
34 1+0 records in
35 1+0 records out
36 0000000 01 - header (1)
37 00 - platform id (0 = 0x86)
38 00 00 - reserved 0
39 00 00 00 00 00 00 00 00 00 00 00 00
40 0000010 00 00 00 00 00 00 00 00 00 00 00 00 - id string
41 aa 55 - checksum
42 55 aa - magic
43
44 0000020 88 - 88 = bootable
45 03 - 3 = 2.88MB diskette
46 00 00 - load segment 0 means default 0x7C0
47 00 - system type (byte 5 of boot image)
48 00 - unused (0)
49 01 00 - 512-byte sector count for initial load
50 4e 0c 00 00 - ptr to virtual disk
51 00 00 00 00
52 0000030 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
53 0000040 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
54 0000050 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
55 0000060 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
56 g% cdsector `{h2d 0c4e} | xd -b
57 1+0 records in
58 1+0 records out
59 0000000 eb 3c 00 00 00 00 00 00 00 00 00 00 02 00 00 00
60 0000010 00 00 00 00 00 00 00 00 12 00 02 00 00 00 00 00
61 0000020 00 00 00 00 00 16 1f 66 6a 00 51 50 06 53
62 31 c0
63
64 FREEBSD
65 0000000 eb 3c 00 00 00 00 00 00 00 00 00 00 02 00 00 00
66 0000010 00 00 00 00 00 00 00 00 12 00 02 00 00 00 00 00
67 0000020 00 00 00 00 00 16 1f 66 6a 00 51 50 06 53
68 31 c0
69
70 DOS 5
71 0000000 eb 3c 90 4d 53 44 4f 53 35 2e 30 00 02 01 01 00
72 0000010 02 e0 00 40 0b f0 09 00 12 00 02 00 00 00 00 00
73 0000020 00 00 00 00 00 00 29 6a 2c e0 16 4e 4f 20 4e 41
74 0000030 4d 45 20 20 20 20 46 41 54 31 32 20 20 20 fa 33
75 0000040 c0 8e d0 bc 00 7c 16 07 bb 78 00 36 c5 37 1e 56
76 0000050 16 53 bf 3e 7c b9 0b 00 fc f3 a4 06 1f c6 45 fe
77 0000060 0f 8b 0e 18 7c 88 4d f9 89 47 02 c7 07 3e 7c fb
78 0000070 cd 13 72 79 33 c0 39 06 13 7c 74 08 8b 0e 13 7c
79 0000080 89 0e 20 7c a0 10 7c f7 26 16 7c 03 06 1c 7c 13
80 0000090 16 1e 7c 03 06 0e 7c 83 d2 00 a3 50 7c 89 16 52
81 00000a0 7c a3 49 7c 89 16 4b 7c b8 20 00 f7 26 11 7c 8b
82
83 NDISK
84 0000000 eb 3c 90 50 6c 61 6e 39 2e 30 30 00 02 01 01 00
85 0000010 02 e0 00 40 0b f0 09 00 12 00 02 00 00 00 00 00
86 0000020 40 0b 00 00 00 00 29 13 00 00 00 43 59 4c 49 4e
87 0000030 44 52 49 43 41 4c 46 41 54 31 32 20 20 20 fa 31
88 0000040 c0 8e d0 8e d8 8e c0 bc ec 7b 89 e5 88 56 12 fb
89 0000050 be ea 7d bf 90 7d ff d7 bf 82 7d ff d7 8b 06 27
90 0000060 7c 8b 16 29 7c bb 00 7e bf 2c 7d ff d7 bb 10 00
91
92 PBSDISK
93 0000000 eb 3c 90 50 6c 61 6e 39 2e 30 30 00 02 01 01 00
94 0000010 02 e0 00 40 0b f0 09 00 12 00 02 00 00 00 00 00
95 0000020 40 0b 00 00 00 00 29 13 00 00 00 43 59 4c 49 4e
96 0000030 44 52 49 43 41 4c 46 41 54 31 32 20 20 20 fa 31
97 0000040 c0 8e d0 8e d8 8e c0 bc f8 7b 89 e5 88 56 00 fb
98 0000050 be f8 7d bf 00 7d ff d7 bf df 7c ff d7 8b 06 27
99 0000060 7c 8b 16 29 7c bb 00 7e bf 89 7c ff d7 bf fb 7c
100 */
101
102 void
Cputbootvol(Cdimg * cd)103 Cputbootvol(Cdimg *cd)
104 {
105 Cputc(cd, 0x00);
106 Cputs(cd, "CD001", 5);
107 Cputc(cd, 0x01);
108 Cputs(cd, "EL TORITO SPECIFICATION", 2+1+6+1+13);
109 Crepeat(cd, 0, 2+16+16+7);
110 cd->bootcatptr = Cwoffset(cd);
111 Cpadblock(cd);
112 }
113
114 void
Cupdatebootvol(Cdimg * cd)115 Cupdatebootvol(Cdimg *cd)
116 {
117 uvlong o;
118
119 o = Cwoffset(cd);
120 Cwseek(cd, cd->bootcatptr);
121 Cputnl(cd, cd->bootcatblock, 4);
122 Cwseek(cd, o);
123 }
124
125 void
Cputbootcat(Cdimg * cd)126 Cputbootcat(Cdimg *cd)
127 {
128 cd->bootcatblock = Cwoffset(cd) / Blocksize;
129 Cputc(cd, 0x01);
130 Cputc(cd, 0x00);
131 Cputc(cd, 0x00);
132 Cputc(cd, 0x00);
133 Crepeat(cd, 0, 12+12);
134
135 /*
136 * either the checksum doesn't include the header word
137 * or it just doesn't matter.
138 */
139 Cputc(cd, 0xAA);
140 Cputc(cd, 0x55);
141 Cputc(cd, 0x55);
142 Cputc(cd, 0xAA);
143
144 cd->bootimageptr = Cwoffset(cd);
145 Cpadblock(cd);
146 }
147
148 enum {
149 Emusectsz = 512, /* bytes per emulated sector */
150 };
151
152 void
Cupdatebootcat(Cdimg * cd)153 Cupdatebootcat(Cdimg *cd)
154 {
155 uvlong o;
156 int n;
157
158 if(cd->bootdirec == nil)
159 return;
160
161 o = Cwoffset(cd);
162 Cwseek(cd, cd->bootimageptr);
163 Cputc(cd, 0x88);
164
165 if(cd->flags & CDbootnoemu)
166 Cputc(cd, 0); /* no disk emulation */
167 else
168 switch(cd->bootdirec->length){
169 default:
170 fprint(2, "warning: boot image is not 1.44MB or 2.88MB; "
171 "pretending 1.44MB\n");
172 /* fall through */
173 case 1440*1024:
174 Cputc(cd, 0x02); /* 1.44MB disk */
175 break;
176 case 2880*1024:
177 Cputc(cd, 0x03); /* 2.88MB disk */
178 break;
179 }
180 Cputnl(cd, 0, 2); /* load segment */
181 Cputc(cd, 0); /* system type */
182 Cputc(cd, 0); /* unused */
183
184 n = 1;
185 if(cd->flags & CDbootnoemu){
186 n = (cd->bootdirec->length + Emusectsz - 1) / Emusectsz;
187 if(n > 4){
188 fprint(2, "warning: boot image too big; "
189 "will only load the first 2K\n");
190 n = 4;
191 }
192 }
193 Cputnl(cd, n, 2); /* Emusectsz-byte sector count for load */
194 Cputnl(cd, cd->bootdirec->block, 4); /* ptr to disk image */
195 Cwseek(cd, o);
196 }
197
198 void
Cfillpbs(Cdimg * cd)199 Cfillpbs(Cdimg *cd)
200 {
201 uvlong o;
202 int n;
203
204 if(cd->bootdirec == nil || cd->loaderdirec == nil)
205 return;
206 o = Cwoffset(cd);
207 Cwseek(cd, 3 + cd->bootdirec->block * Blocksize); /* jmp over magic */
208
209 Cputnl(cd, cd->loaderdirec->block, 4); /* ptr to loader */
210 n = (cd->loaderdirec->length + Blocksize - 1) / Blocksize;
211 Cputnl(cd, n, 4); /* loader size */
212 Cputnl(cd, Blocksize, 4); /* loader size */
213 Cwseek(cd, o);
214 }
215
216 void
findbootimage(Cdimg * cd,Direc * root)217 findbootimage(Cdimg *cd, Direc *root)
218 {
219 Direc *d;
220 d = walkdirec(root, cd->bootimage);
221 if(d == nil){
222 fprint(2, "warning: did not encounter boot image\n");
223 return;
224 }
225
226 cd->bootdirec = d;
227 }
228
229 void
findloader(Cdimg * cd,Direc * root)230 findloader(Cdimg *cd, Direc *root)
231 {
232 Direc *d;
233
234 d = walkdirec(root, cd->loader);
235 if(d == nil){
236 fprint(2, "warning: did not encounter boot loader\n");
237 return;
238 }
239 cd->loaderdirec = d;
240 }
241