1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * Copyright (C) 1991, 1992 Linus Torvalds
4 * Copyright (C) 1997 Martin Mares
5 * Copyright (C) 2007 H. Peter Anvin
6 */
7
8 /*
9 * This file builds a disk-image from three different files:
10 *
11 * - setup: 8086 machine code, sets up system parm
12 * - system: 80386 code for actual system
13 * - zoffset.h: header with ZO_* defines
14 *
15 * It does some checking that all files are of the correct type, and writes
16 * the result to the specified destination, removing headers and padding to
17 * the right amount. It also writes some system data to stdout.
18 */
19
20 /*
21 * Changes by tytso to allow root device specification
22 * High loaded stuff by Hans Lermen & Werner Almesberger, Feb. 1996
23 * Cross compiling fixes by Gertjan van Wingerde, July 1996
24 * Rewritten by Martin Mares, April 1997
25 * Substantially overhauled by H. Peter Anvin, April 2007
26 */
27
28 #include <stdio.h>
29 #include <string.h>
30 #include <stdlib.h>
31 #include <stdarg.h>
32 #include <sys/types.h>
33 #include <sys/stat.h>
34 #include <unistd.h>
35 #include <fcntl.h>
36 #include <sys/mman.h>
37 #include <tools/le_byteshift.h>
38
39 typedef unsigned char u8;
40 typedef unsigned short u16;
41 typedef unsigned int u32;
42
43 /* Minimal number of setup sectors */
44 #define SETUP_SECT_MIN 5
45 #define SETUP_SECT_MAX 64
46
47 /* This must be large enough to hold the entire setup */
48 u8 buf[SETUP_SECT_MAX*512];
49
50 static unsigned long _edata;
51
52 /*----------------------------------------------------------------------*/
53
54 static const u32 crctab32[] = {
55 0x00000000, 0x77073096, 0xee0e612c, 0x990951ba, 0x076dc419,
56 0x706af48f, 0xe963a535, 0x9e6495a3, 0x0edb8832, 0x79dcb8a4,
57 0xe0d5e91e, 0x97d2d988, 0x09b64c2b, 0x7eb17cbd, 0xe7b82d07,
58 0x90bf1d91, 0x1db71064, 0x6ab020f2, 0xf3b97148, 0x84be41de,
59 0x1adad47d, 0x6ddde4eb, 0xf4d4b551, 0x83d385c7, 0x136c9856,
60 0x646ba8c0, 0xfd62f97a, 0x8a65c9ec, 0x14015c4f, 0x63066cd9,
61 0xfa0f3d63, 0x8d080df5, 0x3b6e20c8, 0x4c69105e, 0xd56041e4,
62 0xa2677172, 0x3c03e4d1, 0x4b04d447, 0xd20d85fd, 0xa50ab56b,
63 0x35b5a8fa, 0x42b2986c, 0xdbbbc9d6, 0xacbcf940, 0x32d86ce3,
64 0x45df5c75, 0xdcd60dcf, 0xabd13d59, 0x26d930ac, 0x51de003a,
65 0xc8d75180, 0xbfd06116, 0x21b4f4b5, 0x56b3c423, 0xcfba9599,
66 0xb8bda50f, 0x2802b89e, 0x5f058808, 0xc60cd9b2, 0xb10be924,
67 0x2f6f7c87, 0x58684c11, 0xc1611dab, 0xb6662d3d, 0x76dc4190,
68 0x01db7106, 0x98d220bc, 0xefd5102a, 0x71b18589, 0x06b6b51f,
69 0x9fbfe4a5, 0xe8b8d433, 0x7807c9a2, 0x0f00f934, 0x9609a88e,
70 0xe10e9818, 0x7f6a0dbb, 0x086d3d2d, 0x91646c97, 0xe6635c01,
71 0x6b6b51f4, 0x1c6c6162, 0x856530d8, 0xf262004e, 0x6c0695ed,
72 0x1b01a57b, 0x8208f4c1, 0xf50fc457, 0x65b0d9c6, 0x12b7e950,
73 0x8bbeb8ea, 0xfcb9887c, 0x62dd1ddf, 0x15da2d49, 0x8cd37cf3,
74 0xfbd44c65, 0x4db26158, 0x3ab551ce, 0xa3bc0074, 0xd4bb30e2,
75 0x4adfa541, 0x3dd895d7, 0xa4d1c46d, 0xd3d6f4fb, 0x4369e96a,
76 0x346ed9fc, 0xad678846, 0xda60b8d0, 0x44042d73, 0x33031de5,
77 0xaa0a4c5f, 0xdd0d7cc9, 0x5005713c, 0x270241aa, 0xbe0b1010,
78 0xc90c2086, 0x5768b525, 0x206f85b3, 0xb966d409, 0xce61e49f,
79 0x5edef90e, 0x29d9c998, 0xb0d09822, 0xc7d7a8b4, 0x59b33d17,
80 0x2eb40d81, 0xb7bd5c3b, 0xc0ba6cad, 0xedb88320, 0x9abfb3b6,
81 0x03b6e20c, 0x74b1d29a, 0xead54739, 0x9dd277af, 0x04db2615,
82 0x73dc1683, 0xe3630b12, 0x94643b84, 0x0d6d6a3e, 0x7a6a5aa8,
83 0xe40ecf0b, 0x9309ff9d, 0x0a00ae27, 0x7d079eb1, 0xf00f9344,
84 0x8708a3d2, 0x1e01f268, 0x6906c2fe, 0xf762575d, 0x806567cb,
85 0x196c3671, 0x6e6b06e7, 0xfed41b76, 0x89d32be0, 0x10da7a5a,
86 0x67dd4acc, 0xf9b9df6f, 0x8ebeeff9, 0x17b7be43, 0x60b08ed5,
87 0xd6d6a3e8, 0xa1d1937e, 0x38d8c2c4, 0x4fdff252, 0xd1bb67f1,
88 0xa6bc5767, 0x3fb506dd, 0x48b2364b, 0xd80d2bda, 0xaf0a1b4c,
89 0x36034af6, 0x41047a60, 0xdf60efc3, 0xa867df55, 0x316e8eef,
90 0x4669be79, 0xcb61b38c, 0xbc66831a, 0x256fd2a0, 0x5268e236,
91 0xcc0c7795, 0xbb0b4703, 0x220216b9, 0x5505262f, 0xc5ba3bbe,
92 0xb2bd0b28, 0x2bb45a92, 0x5cb36a04, 0xc2d7ffa7, 0xb5d0cf31,
93 0x2cd99e8b, 0x5bdeae1d, 0x9b64c2b0, 0xec63f226, 0x756aa39c,
94 0x026d930a, 0x9c0906a9, 0xeb0e363f, 0x72076785, 0x05005713,
95 0x95bf4a82, 0xe2b87a14, 0x7bb12bae, 0x0cb61b38, 0x92d28e9b,
96 0xe5d5be0d, 0x7cdcefb7, 0x0bdbdf21, 0x86d3d2d4, 0xf1d4e242,
97 0x68ddb3f8, 0x1fda836e, 0x81be16cd, 0xf6b9265b, 0x6fb077e1,
98 0x18b74777, 0x88085ae6, 0xff0f6a70, 0x66063bca, 0x11010b5c,
99 0x8f659eff, 0xf862ae69, 0x616bffd3, 0x166ccf45, 0xa00ae278,
100 0xd70dd2ee, 0x4e048354, 0x3903b3c2, 0xa7672661, 0xd06016f7,
101 0x4969474d, 0x3e6e77db, 0xaed16a4a, 0xd9d65adc, 0x40df0b66,
102 0x37d83bf0, 0xa9bcae53, 0xdebb9ec5, 0x47b2cf7f, 0x30b5ffe9,
103 0xbdbdf21c, 0xcabac28a, 0x53b39330, 0x24b4a3a6, 0xbad03605,
104 0xcdd70693, 0x54de5729, 0x23d967bf, 0xb3667a2e, 0xc4614ab8,
105 0x5d681b02, 0x2a6f2b94, 0xb40bbe37, 0xc30c8ea1, 0x5a05df1b,
106 0x2d02ef8d
107 };
108
partial_crc32_one(u8 c,u32 crc)109 static u32 partial_crc32_one(u8 c, u32 crc)
110 {
111 return crctab32[(crc ^ c) & 0xff] ^ (crc >> 8);
112 }
113
partial_crc32(const u8 * s,int len,u32 crc)114 static u32 partial_crc32(const u8 *s, int len, u32 crc)
115 {
116 while (len--)
117 crc = partial_crc32_one(*s++, crc);
118 return crc;
119 }
120
die(const char * str,...)121 static void die(const char * str, ...)
122 {
123 va_list args;
124 va_start(args, str);
125 vfprintf(stderr, str, args);
126 va_end(args);
127 fputc('\n', stderr);
128 exit(1);
129 }
130
usage(void)131 static void usage(void)
132 {
133 die("Usage: build setup system zoffset.h image");
134 }
135
136 /*
137 * Parse zoffset.h and find the entry points. We could just #include zoffset.h
138 * but that would mean tools/build would have to be rebuilt every time. It's
139 * not as if parsing it is hard...
140 */
141 #define PARSE_ZOFS(p, sym) do { \
142 if (!strncmp(p, "#define ZO_" #sym " ", 11+sizeof(#sym))) \
143 sym = strtoul(p + 11 + sizeof(#sym), NULL, 16); \
144 } while (0)
145
parse_zoffset(char * fname)146 static void parse_zoffset(char *fname)
147 {
148 FILE *file;
149 char *p;
150 int c;
151
152 file = fopen(fname, "r");
153 if (!file)
154 die("Unable to open `%s': %m", fname);
155 c = fread(buf, 1, sizeof(buf) - 1, file);
156 if (ferror(file))
157 die("read-error on `zoffset.h'");
158 fclose(file);
159 buf[c] = 0;
160
161 p = (char *)buf;
162
163 while (p && *p) {
164 PARSE_ZOFS(p, _edata);
165
166 p = strchr(p, '\n');
167 while (p && (*p == '\r' || *p == '\n'))
168 p++;
169 }
170 }
171
main(int argc,char ** argv)172 int main(int argc, char ** argv)
173 {
174 unsigned int i, sz, setup_sectors;
175 int c;
176 struct stat sb;
177 FILE *file, *dest;
178 int fd;
179 void *kernel;
180 u32 crc = 0xffffffffUL;
181
182 if (argc != 5)
183 usage();
184 parse_zoffset(argv[3]);
185
186 dest = fopen(argv[4], "w");
187 if (!dest)
188 die("Unable to write `%s': %m", argv[4]);
189
190 /* Copy the setup code */
191 file = fopen(argv[1], "r");
192 if (!file)
193 die("Unable to open `%s': %m", argv[1]);
194 c = fread(buf, 1, sizeof(buf), file);
195 if (ferror(file))
196 die("read-error on `setup'");
197 if (c < 1024)
198 die("The setup must be at least 1024 bytes");
199 if (get_unaligned_le16(&buf[510]) != 0xAA55)
200 die("Boot block hasn't got boot flag (0xAA55)");
201 fclose(file);
202
203 /* Pad unused space with zeros */
204 setup_sectors = (c + 4095) / 4096;
205 setup_sectors *= 8;
206 if (setup_sectors < SETUP_SECT_MIN)
207 setup_sectors = SETUP_SECT_MIN;
208 i = setup_sectors*512;
209 memset(buf+c, 0, i-c);
210
211 /* Open and stat the kernel file */
212 fd = open(argv[2], O_RDONLY);
213 if (fd < 0)
214 die("Unable to open `%s': %m", argv[2]);
215 if (fstat(fd, &sb))
216 die("Unable to stat `%s': %m", argv[2]);
217 if (_edata != sb.st_size)
218 die("Unexpected file size `%s': %u != %u", argv[2], _edata,
219 sb.st_size);
220 sz = _edata - 4;
221 kernel = mmap(NULL, sz, PROT_READ, MAP_SHARED, fd, 0);
222 if (kernel == MAP_FAILED)
223 die("Unable to mmap '%s': %m", argv[2]);
224
225 crc = partial_crc32(buf, i, crc);
226 if (fwrite(buf, 1, i, dest) != i)
227 die("Writing setup failed");
228
229 /* Copy the kernel code */
230 crc = partial_crc32(kernel, sz, crc);
231 if (fwrite(kernel, 1, sz, dest) != sz)
232 die("Writing kernel failed");
233
234 /* Write the CRC */
235 put_unaligned_le32(crc, buf);
236 if (fwrite(buf, 1, 4, dest) != 4)
237 die("Writing CRC failed");
238
239 /* Catch any delayed write failures */
240 if (fclose(dest))
241 die("Writing image failed");
242
243 close(fd);
244
245 /* Everything is OK */
246 return 0;
247 }
248