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 <linux/a.out.h> 34#include <errno.h> 35 36#define MINIX_HEADER 32 37 38#define N_MAGIC_OFFSET 1024 39#ifndef __BFD__ 40static int GCC_HEADER = sizeof(struct exec); 41#endif 42 43#ifdef __BIG_KERNEL__ 44#define SYS_SIZE 0xffff 45#else 46#define SYS_SIZE DEF_SYSSIZE 47#endif 48 49#define DEFAULT_MAJOR_ROOT 0 50#define DEFAULT_MINOR_ROOT 0 51 52/* max nr of sectors of setup: don't change unless you also change 53 * bootsect etc */ 54#define SETUP_SECTS 4 55 56#define STRINGIFY(x) #x 57 58typedef union { 59 int i; 60 long l; 61 short s[2]; 62 char b[4]; 63} conv; 64 65long intel_long(long l) 66{ 67 conv t; 68 69 t.b[0] = l & 0xff; l >>= 8; 70 t.b[1] = l & 0xff; l >>= 8; 71 t.b[2] = l & 0xff; l >>= 8; 72 t.b[3] = l & 0xff; l >>= 8; 73 return t.l; 74} 75 76int intel_int(int i) 77{ 78 conv t; 79 80 t.b[0] = i & 0xff; i >>= 8; 81 t.b[1] = i & 0xff; i >>= 8; 82 t.b[2] = i & 0xff; i >>= 8; 83 t.b[3] = i & 0xff; i >>= 8; 84 return t.i; 85} 86 87short intel_short(short l) 88{ 89 conv t; 90 91 t.b[0] = l & 0xff; l >>= 8; 92 t.b[1] = l & 0xff; l >>= 8; 93 return t.s[0]; 94} 95 96void die(const char * str) 97{ 98 fprintf(stderr,"%s\n",str); 99 exit(1); 100} 101 102void usage(void) 103{ 104 die("Usage: build bootsect setup system [rootdev] [> image]"); 105} 106 107int main(int argc, char ** argv) 108{ 109 int i,c,id,sz,tmp_int; 110 unsigned long sys_size, tmp_long; 111 char buf[1024]; 112#ifndef __BFD__ 113 struct exec *ex = (struct exec *)buf; 114#endif 115 char major_root, minor_root; 116 struct stat sb; 117 unsigned char setup_sectors; 118 119 if ((argc < 4) || (argc > 5)) 120 usage(); 121 if (argc > 4) { 122 if (!strcmp(argv[4], "CURRENT")) { 123 if (stat("/", &sb)) { 124 perror("/"); 125 die("Couldn't stat /"); 126 } 127 major_root = major(sb.st_dev); 128 minor_root = minor(sb.st_dev); 129 } else if (strcmp(argv[4], "FLOPPY")) { 130 if (stat(argv[4], &sb)) { 131 perror(argv[4]); 132 die("Couldn't stat root device."); 133 } 134 major_root = major(sb.st_rdev); 135 minor_root = minor(sb.st_rdev); 136 } else { 137 major_root = 0; 138 minor_root = 0; 139 } 140 } else { 141 major_root = DEFAULT_MAJOR_ROOT; 142 minor_root = DEFAULT_MINOR_ROOT; 143 } 144 fprintf(stderr, "Root device is (%d, %d)\n", major_root, minor_root); 145 for (i=0;i<sizeof buf; i++) buf[i]=0; 146 if ((id=open(argv[1],O_RDONLY,0))<0) 147 die("Unable to open 'boot'"); 148 if (read(id,buf,MINIX_HEADER) != MINIX_HEADER) 149 die("Unable to read header of 'boot'"); 150 if (((long *) buf)[0]!=intel_long(0x04100301)) 151 die("Non-Minix header of 'boot'"); 152 if (((long *) buf)[1]!=intel_long(MINIX_HEADER)) 153 die("Non-Minix header of 'boot'"); 154 if (((long *) buf)[3] != 0) 155 die("Illegal data segment in 'boot'"); 156 if (((long *) buf)[4] != 0) 157 die("Illegal bss in 'boot'"); 158 if (((long *) buf)[5] != 0) 159 die("Non-Minix header of 'boot'"); 160 if (((long *) buf)[7] != 0) 161 die("Illegal symbol table in 'boot'"); 162 i=read(id,buf,sizeof buf); 163 fprintf(stderr,"Boot sector %d bytes.\n",i); 164 if (i != 512) 165 die("Boot block must be exactly 512 bytes"); 166 if ((*(unsigned short *)(buf+510)) != (unsigned short)intel_short(0xAA55)) 167 die("Boot block hasn't got boot flag (0xAA55)"); 168 buf[508] = (char) minor_root; 169 buf[509] = (char) major_root; 170 i=write(1,buf,512); 171 if (i!=512) 172 die("Write call failed"); 173 close (id); 174 175 if ((id=open(argv[2],O_RDONLY,0))<0) 176 die("Unable to open 'setup'"); 177 if (read(id,buf,MINIX_HEADER) != MINIX_HEADER) 178 die("Unable to read header of 'setup'"); 179 if (((long *) buf)[0]!=intel_long(0x04100301)) 180 die("Non-Minix header of 'setup'"); 181 if (((long *) buf)[1]!=intel_long(MINIX_HEADER)) 182 die("Non-Minix header of 'setup'"); 183 if (((long *) buf)[3] != 0) 184 die("Illegal data segment in 'setup'"); 185 if (((long *) buf)[4] != 0) 186 die("Illegal bss in 'setup'"); 187 if (((long *) buf)[5] != 0) 188 die("Non-Minix header of 'setup'"); 189 if (((long *) buf)[7] != 0) 190 die("Illegal symbol table in 'setup'"); 191 for (i=0 ; (c=read(id,buf,sizeof buf))>0 ; i+=c ) 192#ifdef __BIG_KERNEL__ 193 { 194 if (!i) { 195 /* Working with memcpy because of alignment constraints 196 on Sparc - Gertjan */ 197 memcpy(&tmp_long, &buf[2], sizeof(long)); 198 if (tmp_long != intel_long(0x53726448) ) 199 die("Wrong magic in loader header of 'setup'"); 200 memcpy(&tmp_int, &buf[6], sizeof(int)); 201 if (tmp_int < intel_int(0x200)) 202 die("Wrong version of loader header of 'setup'"); 203 buf[0x11] = 1; /* LOADED_HIGH */ 204 tmp_long = intel_long(0x100000); 205 memcpy(&buf[0x14], &tmp_long, sizeof(long)); /* code32_start */ 206 } 207#endif 208 if (write(1,buf,c)!=c) 209 die("Write call failed"); 210#ifdef __BIG_KERNEL__ 211 } 212#endif 213 if (c != 0) 214 die("read-error on 'setup'"); 215 close (id); 216 setup_sectors = (unsigned char)((i + 511) / 512); 217 /* for compatibility with LILO */ 218 if (setup_sectors < SETUP_SECTS) 219 setup_sectors = SETUP_SECTS; 220 fprintf(stderr,"Setup is %d bytes.\n",i); 221 for (c=0 ; c<sizeof(buf) ; c++) 222 buf[c] = '\0'; 223 while (i < setup_sectors * 512) { 224 c = setup_sectors * 512 - i; 225 if (c > sizeof(buf)) 226 c = sizeof(buf); 227 if (write(1,buf,c) != c) 228 die("Write call failed"); 229 i += c; 230 } 231 232 if ((id=open(argv[3],O_RDONLY,0))<0) 233 die("Unable to open 'system'"); 234#ifndef __BFD__ 235 if (read(id,buf,GCC_HEADER) != GCC_HEADER) 236 die("Unable to read header of 'system'"); 237 if (N_MAGIC(*ex) == ZMAGIC) { 238 GCC_HEADER = N_MAGIC_OFFSET; 239 lseek(id, GCC_HEADER, SEEK_SET); 240 } else if (N_MAGIC(*ex) != QMAGIC) 241 die("Non-GCC header of 'system'"); 242 fprintf(stderr,"System is %d kB (%d kB code, %d kB data and %d kB bss)\n", 243 (ex->a_text+ex->a_data+ex->a_bss)/1024, 244 ex->a_text /1024, 245 ex->a_data /1024, 246 ex->a_bss /1024); 247 sz = N_SYMOFF(*ex) - GCC_HEADER + 4; 248#else 249 if (fstat (id, &sb)) { 250 perror ("fstat"); 251 die ("Unable to stat 'system'"); 252 } 253 sz = sb.st_size; 254 fprintf (stderr, "System is %d kB\n", sz/1024); 255#endif 256 sys_size = (sz + 15) / 16; 257 if (sys_size > SYS_SIZE) 258 die("System is too big"); 259 while (sz > 0) { 260 int l, n; 261 262 l = sz; 263 if (l > sizeof(buf)) 264 l = sizeof(buf); 265 if ((n=read(id, buf, l)) != l) { 266 if (n == -1) 267 perror(argv[1]); 268 else 269 fprintf(stderr, "Unexpected EOF\n"); 270 die("Can't read 'system'"); 271 } 272 if (write(1, buf, l) != l) 273 die("Write failed"); 274 sz -= l; 275 } 276 close(id); 277 if (lseek(1, 497, 0) == 497) { 278 if (write(1, &setup_sectors, 1) != 1) 279 die("Write of setup sectors failed"); 280 } 281 if (lseek(1,500,0) == 500) { 282 buf[0] = (sys_size & 0xff); 283 buf[1] = ((sys_size >> 8) & 0xff); 284 if (write(1, buf, 2) != 2) 285 die("Write failed"); 286 } 287 return(0); 288} 289