1 /*
2 * linux/tools/build.c
3 *
4 * Copyright (C) 1991, 1992 Linus Torvalds
5 */
6
7 /*
8 * This file builds a disk-image from three different files:
9 *
10 * - bootsect: exactly 512 bytes of 8086 machine code, loads the rest
11 * - setup: 8086 machine code, sets up system parm
12 * - system: 80386 code for actual system
13 *
14 * It does some checking that all files are of the correct type, and
15 * just writes the result to stdout, removing headers and padding to
16 * the right amount. It also writes some system data to stderr.
17 */
18
19 /*
20 * Changes by tytso to allow root device specification
21 * High loaded stuff by Hans Lermen & Werner Almesberger, Feb. 1996
22 * Cross compiling fixes by Gertjan van Wingerde, July 1996
23 */
24
25 #include <stdio.h> /* fprintf */
26 #include <string.h>
27 #include <stdlib.h> /* contains exit */
28 #include <sys/types.h> /* unistd.h needs this */
29 #include <sys/stat.h>
30 #include <sys/sysmacros.h>
31 #include <unistd.h> /* contains read/write */
32 #include <fcntl.h>
33 #include <errno.h>
34
35 #define MINIX_HEADER 32
36
37 #define N_MAGIC_OFFSET 1024
38 #ifndef __BFD__
39 static int GCC_HEADER = sizeof(struct exec);
40 #endif
41
42 #ifdef __BIG_KERNEL__
43 #define SYS_SIZE 0xffff
44 #else
45 #define SYS_SIZE DEF_SYSSIZE
46 #endif
47
48 #define DEFAULT_MAJOR_ROOT 0
49 #define DEFAULT_MINOR_ROOT 0
50
51 /* max nr of sectors of setup: don't change unless you also change
52 * bootsect etc */
53 #define SETUP_SECTS 4
54
55 #define STRINGIFY(x) #x
56
57 typedef union {
58 int i;
59 long l;
60 short s[2];
61 char b[4];
62 } conv;
63
intel_long(long l)64 long intel_long(long l)
65 {
66 conv t;
67
68 t.b[0] = l & 0xff; l >>= 8;
69 t.b[1] = l & 0xff; l >>= 8;
70 t.b[2] = l & 0xff; l >>= 8;
71 t.b[3] = l & 0xff; l >>= 8;
72 return t.l;
73 }
74
intel_int(int i)75 int intel_int(int i)
76 {
77 conv t;
78
79 t.b[0] = i & 0xff; i >>= 8;
80 t.b[1] = i & 0xff; i >>= 8;
81 t.b[2] = i & 0xff; i >>= 8;
82 t.b[3] = i & 0xff; i >>= 8;
83 return t.i;
84 }
85
intel_short(short l)86 short intel_short(short l)
87 {
88 conv t;
89
90 t.b[0] = l & 0xff; l >>= 8;
91 t.b[1] = l & 0xff; l >>= 8;
92 return t.s[0];
93 }
94
die(const char * str)95 void die(const char * str)
96 {
97 fprintf(stderr,"%s\n",str);
98 exit(1);
99 }
100
usage(void)101 void usage(void)
102 {
103 die("Usage: build bootsect setup system [rootdev] [> image]");
104 }
105
main(int argc,char ** argv)106 int main(int argc, char ** argv)
107 {
108 int i,c,id,sz,tmp_int;
109 unsigned long sys_size, tmp_long;
110 char buf[1024];
111 #ifndef __BFD__
112 struct exec *ex = (struct exec *)buf;
113 #endif
114 char major_root, minor_root;
115 struct stat sb;
116 unsigned char setup_sectors;
117
118 if ((argc < 4) || (argc > 5))
119 usage();
120 if (argc > 4) {
121 if (!strcmp(argv[4], "CURRENT")) {
122 if (stat("/", &sb)) {
123 perror("/");
124 die("Couldn't stat /");
125 }
126 major_root = major(sb.st_dev);
127 minor_root = minor(sb.st_dev);
128 } else if (strcmp(argv[4], "FLOPPY")) {
129 if (stat(argv[4], &sb)) {
130 perror(argv[4]);
131 die("Couldn't stat root device.");
132 }
133 major_root = major(sb.st_rdev);
134 minor_root = minor(sb.st_rdev);
135 } else {
136 major_root = 0;
137 minor_root = 0;
138 }
139 } else {
140 major_root = DEFAULT_MAJOR_ROOT;
141 minor_root = DEFAULT_MINOR_ROOT;
142 }
143 fprintf(stderr, "Root device is (%d, %d)\n", major_root, minor_root);
144 for (i=0;i<sizeof buf; i++) buf[i]=0;
145 if ((id=open(argv[1],O_RDONLY,0))<0)
146 die("Unable to open 'boot'");
147 if (read(id,buf,MINIX_HEADER) != MINIX_HEADER)
148 die("Unable to read header of 'boot'");
149 if (((long *) buf)[0]!=intel_long(0x04100301))
150 die("Non-Minix header of 'boot'");
151 if (((long *) buf)[1]!=intel_long(MINIX_HEADER))
152 die("Non-Minix header of 'boot'");
153 if (((long *) buf)[3] != 0)
154 die("Illegal data segment in 'boot'");
155 if (((long *) buf)[4] != 0)
156 die("Illegal bss in 'boot'");
157 if (((long *) buf)[5] != 0)
158 die("Non-Minix header of 'boot'");
159 if (((long *) buf)[7] != 0)
160 die("Illegal symbol table in 'boot'");
161 i=read(id,buf,sizeof buf);
162 fprintf(stderr,"Boot sector %d bytes.\n",i);
163 if (i != 512)
164 die("Boot block must be exactly 512 bytes");
165 if ((*(unsigned short *)(buf+510)) != (unsigned short)intel_short(0xAA55))
166 die("Boot block hasn't got boot flag (0xAA55)");
167 buf[508] = (char) minor_root;
168 buf[509] = (char) major_root;
169 i=write(1,buf,512);
170 if (i!=512)
171 die("Write call failed");
172 close (id);
173
174 if ((id=open(argv[2],O_RDONLY,0))<0)
175 die("Unable to open 'setup'");
176 if (read(id,buf,MINIX_HEADER) != MINIX_HEADER)
177 die("Unable to read header of 'setup'");
178 if (((long *) buf)[0]!=intel_long(0x04100301))
179 die("Non-Minix header of 'setup'");
180 if (((long *) buf)[1]!=intel_long(MINIX_HEADER))
181 die("Non-Minix header of 'setup'");
182 if (((long *) buf)[3] != 0)
183 die("Illegal data segment in 'setup'");
184 if (((long *) buf)[4] != 0)
185 die("Illegal bss in 'setup'");
186 if (((long *) buf)[5] != 0)
187 die("Non-Minix header of 'setup'");
188 if (((long *) buf)[7] != 0)
189 die("Illegal symbol table in 'setup'");
190 for (i=0 ; (c=read(id,buf,sizeof buf))>0 ; i+=c )
191 #ifdef __BIG_KERNEL__
192 {
193 if (!i) {
194 /* Working with memcpy because of alignment constraints
195 on Sparc - Gertjan */
196 memcpy(&tmp_long, &buf[2], sizeof(long));
197 if (tmp_long != intel_long(0x53726448) )
198 die("Wrong magic in loader header of 'setup'");
199 memcpy(&tmp_int, &buf[6], sizeof(int));
200 if (tmp_int < intel_int(0x200))
201 die("Wrong version of loader header of 'setup'");
202 buf[0x11] = 1; /* LOADED_HIGH */
203 tmp_long = intel_long(0x100000);
204 memcpy(&buf[0x14], &tmp_long, sizeof(long)); /* code32_start */
205 }
206 #endif
207 if (write(1,buf,c)!=c)
208 die("Write call failed");
209 #ifdef __BIG_KERNEL__
210 }
211 #endif
212 if (c != 0)
213 die("read-error on 'setup'");
214 close (id);
215 setup_sectors = (unsigned char)((i + 511) / 512);
216 /* for compatibility with LILO */
217 if (setup_sectors < SETUP_SECTS)
218 setup_sectors = SETUP_SECTS;
219 fprintf(stderr,"Setup is %d bytes.\n",i);
220 for (c=0 ; c<sizeof(buf) ; c++)
221 buf[c] = '\0';
222 while (i < setup_sectors * 512) {
223 c = setup_sectors * 512 - i;
224 if (c > sizeof(buf))
225 c = sizeof(buf);
226 if (write(1,buf,c) != c)
227 die("Write call failed");
228 i += c;
229 }
230
231 if ((id=open(argv[3],O_RDONLY,0))<0)
232 die("Unable to open 'system'");
233 #ifndef __BFD__
234 if (read(id,buf,GCC_HEADER) != GCC_HEADER)
235 die("Unable to read header of 'system'");
236 if (N_MAGIC(*ex) == ZMAGIC) {
237 GCC_HEADER = N_MAGIC_OFFSET;
238 lseek(id, GCC_HEADER, SEEK_SET);
239 } else if (N_MAGIC(*ex) != QMAGIC)
240 die("Non-GCC header of 'system'");
241 fprintf(stderr,"System is %d kB (%d kB code, %d kB data and %d kB bss)\n",
242 (ex->a_text+ex->a_data+ex->a_bss)/1024,
243 ex->a_text /1024,
244 ex->a_data /1024,
245 ex->a_bss /1024);
246 sz = N_SYMOFF(*ex) - GCC_HEADER + 4;
247 #else
248 if (fstat (id, &sb)) {
249 perror ("fstat");
250 die ("Unable to stat 'system'");
251 }
252 sz = sb.st_size;
253 fprintf (stderr, "System is %d kB\n", sz/1024);
254 #endif
255 sys_size = (sz + 15) / 16;
256 if (sys_size > SYS_SIZE)
257 die("System is too big");
258 while (sz > 0) {
259 int l, n;
260
261 l = sz;
262 if (l > sizeof(buf))
263 l = sizeof(buf);
264 if ((n=read(id, buf, l)) != l) {
265 if (n == -1)
266 perror(argv[1]);
267 else
268 fprintf(stderr, "Unexpected EOF\n");
269 die("Can't read 'system'");
270 }
271 if (write(1, buf, l) != l)
272 die("Write failed");
273 sz -= l;
274 }
275 close(id);
276 if (lseek(1, 497, 0) == 497) {
277 if (write(1, &setup_sectors, 1) != 1)
278 die("Write of setup sectors failed");
279 }
280 if (lseek(1,500,0) == 500) {
281 buf[0] = (sys_size & 0xff);
282 buf[1] = ((sys_size >> 8) & 0xff);
283 if (write(1, buf, 2) != 2)
284 die("Write failed");
285 }
286 return(0);
287 }
288