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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 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 | /* * linux/tools/build.c * * Copyright (C) 1991, 1992 Linus Torvalds */ /* * This file builds a disk-image from three different files: * * - bootsect: max 510 bytes of 8086 machine code, loads the rest * - setup: max 4 sectors of 8086 machine code, sets up system parm * - system: 80386 code for actual system * * It does some checking that all files are of the correct type, and * just writes the result to stdout, removing headers and padding to * the right amount. It also writes some system data to stderr. */ /* * Changes by tytso to allow root device specification */ #include <stdio.h> /* fprintf */ #include <string.h> #include <stdlib.h> /* contains exit */ #include <sys/types.h> /* unistd.h needs this */ #include <sys/stat.h> #include <sys/sysmacros.h> #include <unistd.h> /* contains read/write */ #include <fcntl.h> #include <linux/config.h> #include <linux/a.out.h> #define MINIX_HEADER 32 #define GCC_HEADER 1024 #define SYS_SIZE DEF_SYSSIZE #define DEFAULT_MAJOR_ROOT 0 #define DEFAULT_MINOR_ROOT 0 /* max nr of sectors of setup: don't change unless you also change * bootsect etc */ #define SETUP_SECTS 4 #define STRINGIFY(x) #x typedef union { long l; short s[2]; char b[4]; } conv; long intel_long(long l) { conv t; t.b[0] = l & 0xff; l >>= 8; t.b[1] = l & 0xff; l >>= 8; t.b[2] = l & 0xff; l >>= 8; t.b[3] = l & 0xff; l >>= 8; return t.l; } short intel_short(short l) { conv t; t.b[0] = l & 0xff; l >>= 8; t.b[1] = l & 0xff; l >>= 8; return t.s[0]; } void die(char * str) { fprintf(stderr,"%s\n",str); exit(1); } void usage(void) { die("Usage: build bootsect setup system [rootdev] [> image]"); } int main(int argc, char ** argv) { int i,c,id, sz; unsigned long sys_size; char buf[1024]; struct exec *ex = (struct exec *)buf; char major_root, minor_root; struct stat sb; if ((argc < 4) || (argc > 5)) usage(); if (argc > 4) { if (!strcmp(argv[4], "CURRENT")) { if (stat("/", &sb)) { perror("/"); die("Couldn't stat /"); } major_root = major(sb.st_dev); minor_root = minor(sb.st_dev); } else if (strcmp(argv[4], "FLOPPY")) { if (stat(argv[4], &sb)) { perror(argv[4]); die("Couldn't stat root device."); } major_root = major(sb.st_rdev); minor_root = minor(sb.st_rdev); } else { major_root = 0; minor_root = 0; } } else { major_root = DEFAULT_MAJOR_ROOT; minor_root = DEFAULT_MINOR_ROOT; } fprintf(stderr, "Root device is (%d, %d)\n", major_root, minor_root); for (i=0;i<sizeof buf; i++) buf[i]=0; if ((id=open(argv[1],O_RDONLY,0))<0) die("Unable to open 'boot'"); if (read(id,buf,MINIX_HEADER) != MINIX_HEADER) die("Unable to read header of 'boot'"); if (((long *) buf)[0]!=intel_long(0x04100301)) die("Non-Minix header of 'boot'"); if (((long *) buf)[1]!=intel_long(MINIX_HEADER)) die("Non-Minix header of 'boot'"); if (((long *) buf)[3] != 0) die("Illegal data segment in 'boot'"); if (((long *) buf)[4] != 0) die("Illegal bss in 'boot'"); if (((long *) buf)[5] != 0) die("Non-Minix header of 'boot'"); if (((long *) buf)[7] != 0) die("Illegal symbol table in 'boot'"); i=read(id,buf,sizeof buf); fprintf(stderr,"Boot sector %d bytes.\n",i); if (i != 512) die("Boot block must be exactly 512 bytes"); if ((*(unsigned short *)(buf+510)) != (unsigned short)intel_short(0xAA55)) die("Boot block hasn't got boot flag (0xAA55)"); buf[508] = (char) minor_root; buf[509] = (char) major_root; i=write(1,buf,512); if (i!=512) die("Write call failed"); close (id); if ((id=open(argv[2],O_RDONLY,0))<0) die("Unable to open 'setup'"); if (read(id,buf,MINIX_HEADER) != MINIX_HEADER) die("Unable to read header of 'setup'"); if (((long *) buf)[0]!=intel_long(0x04100301)) die("Non-Minix header of 'setup'"); if (((long *) buf)[1]!=intel_long(MINIX_HEADER)) die("Non-Minix header of 'setup'"); if (((long *) buf)[3] != 0) die("Illegal data segment in 'setup'"); if (((long *) buf)[4] != 0) die("Illegal bss in 'setup'"); if (((long *) buf)[5] != 0) die("Non-Minix header of 'setup'"); if (((long *) buf)[7] != 0) die("Illegal symbol table in 'setup'"); for (i=0 ; (c=read(id,buf,sizeof buf))>0 ; i+=c ) if (write(1,buf,c)!=c) die("Write call failed"); if (c != 0) die("read-error on 'setup'"); close (id); if (i > SETUP_SECTS*512) die("Setup exceeds " STRINGIFY(SETUP_SECTS) " sectors - rewrite build/boot/setup"); fprintf(stderr,"Setup is %d bytes.\n",i); for (c=0 ; c<sizeof(buf) ; c++) buf[c] = '\0'; while (i<SETUP_SECTS*512) { c = SETUP_SECTS*512-i; if (c > sizeof(buf)) c = sizeof(buf); if (write(1,buf,c) != c) die("Write call failed"); i += c; } if ((id=open(argv[3],O_RDONLY,0))<0) die("Unable to open 'system'"); if (read(id,buf,GCC_HEADER) != GCC_HEADER) die("Unable to read header of 'system'"); if (N_MAGIC(*ex) != ZMAGIC) die("Non-GCC header of 'system'"); fprintf(stderr,"System is %d kB (%d kB code, %d kB data and %d kB bss)\n", (ex->a_text+ex->a_data+ex->a_bss)/1024, ex->a_text /1024, ex->a_data /1024, ex->a_bss /1024); sz = N_SYMOFF(*ex) - GCC_HEADER + 4; sys_size = (sz + 15) / 16; if (sys_size > SYS_SIZE) die("System is too big"); while (sz > 0) { int l, n; l = sz; if (l > sizeof(buf)) l = sizeof(buf); if ((n=read(id, buf, l)) != l) { if (n == -1) perror(argv[1]); else fprintf(stderr, "Unexpected EOF\n"); die("Can't read 'system'"); } write(1, buf, l); sz -= l; } close(id); if (lseek(1,500,0) == 500) { buf[0] = (sys_size & 0xff); buf[1] = ((sys_size >> 8) & 0xff); write(1, buf, 2); } return(0); } |