1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
|
#include <u.h>
#include <libc.h>
#include <bio.h>
#include <libsec.h>
#include "iso9660.h"
/* FreeBSD 4.5 installation CD for reference
g% cdsector 17 | xd -b
1+0 records in
1+0 records out
0000000 00 - volume descriptor type (0)
43 44 30 30 31 - "CD001"
01 - volume descriptor version (1)
45 4c 20 54 4f 52 49 54 4f
0000010 20 53 50 45 43 49 46 49 43 41 54 49 4f 4e 00 00
0000020 00 00 00 00 00 00 00 - 7-39 boot system identifier
"EL TORITO SPECIFICATION"
00 00 00 00 00 00 00 00 00
0000030 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
0000040 00 00 00 00 00 00 00 - 39-71 boot identifier
boot system use:
absolute pointer to the boot catalog??
4d 0c 00 00 00 00 00 00 00
0000050 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
0000580 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
0000590 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
00005a0 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
g% cdsector 3149 | xd -b # 0x0c4d
1+0 records in
1+0 records out
0000000 01 - header (1)
00 - platform id (0 = 0x86)
00 00 - reserved 0
00 00 00 00 00 00 00 00 00 00 00 00
0000010 00 00 00 00 00 00 00 00 00 00 00 00 - id string
aa 55 - checksum
55 aa - magic
0000020 88 - 88 = bootable
03 - 3 = 2.88MB diskette
00 00 - load segment 0 means default 0x7C0
00 - system type (byte 5 of boot image)
00 - unused (0)
01 00 - 512-byte sector count for initial load
4e 0c 00 00 - ptr to virtual disk
00 00 00 00
0000030 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
0000040 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
0000050 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
0000060 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
g% cdsector `{h2d 0c4e} | xd -b
1+0 records in
1+0 records out
0000000 eb 3c 00 00 00 00 00 00 00 00 00 00 02 00 00 00
0000010 00 00 00 00 00 00 00 00 12 00 02 00 00 00 00 00
0000020 00 00 00 00 00 16 1f 66 6a 00 51 50 06 53
31 c0
FREEBSD
0000000 eb 3c 00 00 00 00 00 00 00 00 00 00 02 00 00 00
0000010 00 00 00 00 00 00 00 00 12 00 02 00 00 00 00 00
0000020 00 00 00 00 00 16 1f 66 6a 00 51 50 06 53
31 c0
DOS 5
0000000 eb 3c 90 4d 53 44 4f 53 35 2e 30 00 02 01 01 00
0000010 02 e0 00 40 0b f0 09 00 12 00 02 00 00 00 00 00
0000020 00 00 00 00 00 00 29 6a 2c e0 16 4e 4f 20 4e 41
0000030 4d 45 20 20 20 20 46 41 54 31 32 20 20 20 fa 33
0000040 c0 8e d0 bc 00 7c 16 07 bb 78 00 36 c5 37 1e 56
0000050 16 53 bf 3e 7c b9 0b 00 fc f3 a4 06 1f c6 45 fe
0000060 0f 8b 0e 18 7c 88 4d f9 89 47 02 c7 07 3e 7c fb
0000070 cd 13 72 79 33 c0 39 06 13 7c 74 08 8b 0e 13 7c
0000080 89 0e 20 7c a0 10 7c f7 26 16 7c 03 06 1c 7c 13
0000090 16 1e 7c 03 06 0e 7c 83 d2 00 a3 50 7c 89 16 52
00000a0 7c a3 49 7c 89 16 4b 7c b8 20 00 f7 26 11 7c 8b
NDISK
0000000 eb 3c 90 50 6c 61 6e 39 2e 30 30 00 02 01 01 00
0000010 02 e0 00 40 0b f0 09 00 12 00 02 00 00 00 00 00
0000020 40 0b 00 00 00 00 29 13 00 00 00 43 59 4c 49 4e
0000030 44 52 49 43 41 4c 46 41 54 31 32 20 20 20 fa 31
0000040 c0 8e d0 8e d8 8e c0 bc ec 7b 89 e5 88 56 12 fb
0000050 be ea 7d bf 90 7d ff d7 bf 82 7d ff d7 8b 06 27
0000060 7c 8b 16 29 7c bb 00 7e bf 2c 7d ff d7 bb 10 00
PBSDISK
0000000 eb 3c 90 50 6c 61 6e 39 2e 30 30 00 02 01 01 00
0000010 02 e0 00 40 0b f0 09 00 12 00 02 00 00 00 00 00
0000020 40 0b 00 00 00 00 29 13 00 00 00 43 59 4c 49 4e
0000030 44 52 49 43 41 4c 46 41 54 31 32 20 20 20 fa 31
0000040 c0 8e d0 8e d8 8e c0 bc f8 7b 89 e5 88 56 00 fb
0000050 be f8 7d bf 00 7d ff d7 bf df 7c ff d7 8b 06 27
0000060 7c 8b 16 29 7c bb 00 7e bf 89 7c ff d7 bf fb 7c
*/
void
Cputbootvol(Cdimg *cd)
{
Cputc(cd, 0x00);
Cputs(cd, "CD001", 5);
Cputc(cd, 0x01);
Cputs(cd, "EL TORITO SPECIFICATION", 2+1+6+1+13);
Crepeat(cd, 0, 2+16+16+7);
cd->bootcatptr = Cwoffset(cd);
Cpadblock(cd);
}
void
Cupdatebootvol(Cdimg *cd)
{
ulong o;
o = Cwoffset(cd);
Cwseek(cd, cd->bootcatptr);
Cputnl(cd, cd->bootcatblock, 4);
Cwseek(cd, o);
}
void
Cputbootcat(Cdimg *cd)
{
cd->bootcatblock = Cwoffset(cd) / Blocksize;
Cputc(cd, 0x01);
Cputc(cd, 0x00);
Cputc(cd, 0x00);
Cputc(cd, 0x00);
Crepeat(cd, 0, 12+12);
/*
* either the checksum doesn't include the header word
* or it just doesn't matter.
*/
Cputc(cd, 0xAA);
Cputc(cd, 0x55);
Cputc(cd, 0x55);
Cputc(cd, 0xAA);
cd->bootimageptr = Cwoffset(cd);
Cpadblock(cd);
}
void
Cupdatebootcat(Cdimg *cd)
{
ulong o;
if(cd->bootdirec == nil)
return;
o = Cwoffset(cd);
Cwseek(cd, cd->bootimageptr);
Cputc(cd, 0x88);
switch(cd->bootdirec->length){
default:
fprint(2, "warning: boot image is not 1.44MB or 2.88MB; pretending 1.44MB\n");
case 1440*1024:
Cputc(cd, 0x02); /* 1.44MB disk */
break;
case 2880*1024:
Cputc(cd, 0x03); /* 2.88MB disk */
break;
}
Cputnl(cd, 0, 2); /* load segment */
Cputc(cd, 0); /* system type */
Cputc(cd, 0); /* unused */
Cputnl(cd, 1, 2); /* 512-byte sector count for load */
Cputnl(cd, cd->bootdirec->block, 4); /* ptr to disk image */
Cwseek(cd, o);
}
void
findbootimage(Cdimg *cd, Direc *root)
{
Direc *d;
d = walkdirec(root, cd->bootimage);
if(d == nil){
fprint(2, "warning: did not encounter boot image\n");
return;
}
cd->bootdirec = d;
}
|