elf2bb.c revision 1.9
1 /* $NetBSD: elf2bb.c,v 1.9 2004/11/28 07:00:53 jmc Exp $ */ 2 3 /*- 4 * Copyright (c) 1996 The NetBSD Foundation, Inc. 5 * All rights reserved. 6 * 7 * This code is derived from software contributed to The NetBSD Foundation 8 * by Ignatios Souvatzis. 9 * 10 * Redistribution and use in source and binary forms, with or without 11 * modification, are permitted provided that the following conditions 12 * are met: 13 * 1. Redistributions of source code must retain the above copyright 14 * notice, this list of conditions and the following disclaimer. 15 * 2. Redistributions in binary form must reproduce the above copyright 16 * notice, this list of conditions and the following disclaimer in the 17 * documentation and/or other materials provided with the distribution. 18 * 3. All advertising materials mentioning features or use of this software 19 * must display the following acknowledgement: 20 * This product includes software developed by the NetBSD 21 * Foundation, Inc. and its contributors. 22 * 4. Neither the name of The NetBSD Foundation nor the names of its 23 * contributors may be used to endorse or promote products derived 24 * from this software without specific prior written permission. 25 * 26 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS 27 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 28 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 29 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS 30 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 31 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 32 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 33 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 34 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 35 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 36 * POSSIBILITY OF SUCH DAMAGE. 37 */ 38 39 #if HAVE_NBTOOL_CONFIG_H 40 #include "nbtool_config.h" 41 #endif 42 43 #include <sys/types.h> 44 45 #include <err.h> 46 #include <fcntl.h> 47 #include <stdio.h> 48 #include <stdlib.h> 49 #include <string.h> 50 #include <unistd.h> 51 52 #include <sys/mman.h> /* of the machine we're running on */ 53 #include <sys/endian.h> /* of the machine we're running on */ 54 55 #include <sys/exec_elf.h> /* TARGET */ 56 #ifndef R_68K_32 /* XXX host not m68k XXX */ 57 #define R_68K_32 1 58 #define R_68K_PC32 4 59 #define R_68K_PC16 5 60 #endif 61 62 #include "elf2bb.h" 63 #include "chksum.h" 64 65 void usage(void); 66 int intcmp(const void *, const void *); 67 int main(int argc, char *argv[]); 68 69 #ifdef DEBUG 70 #define dprintf(x) if (debug) printf x 71 #else 72 #define dprintf(x) 73 #endif 74 int debug; 75 76 #define BBSIZE 8192 77 78 char *progname; 79 int bbsize = BBSIZE; 80 u_int8_t *buffer; 81 u_int32_t *relbuf; 82 /* can't have more relocs than that*/ 83 84 int 85 intcmp(const void *i, const void *j) 86 { 87 int r; 88 89 r = (*(u_int32_t *)i) < (*(u_int32_t *)j); 90 91 return 2*r-1; 92 } 93 94 int 95 main(int argc, char *argv[]) 96 { 97 int ifd, ofd; 98 u_int mid, flags, magic; 99 caddr_t image; 100 Elf32_Ehdr *eh; 101 Elf32_Shdr *sh; 102 char *shstrtab; 103 Elf32_Sym *symtab; 104 char *strtab; 105 int eval(Elf32_Sym *, u_int32_t *); 106 u_int32_t *lptr; 107 int i, l, delta; 108 u_int8_t *rpo; 109 u_int32_t oldaddr, addrdiff; 110 u_int32_t tsz, dsz, bsz, trsz, drsz, entry, relver; 111 u_int32_t pcrelsz, r32sz; 112 int sumsize = 16; 113 int c; 114 u_int32_t *sect_offset; 115 int undefsyms; 116 117 118 progname = argv[0]; 119 120 /* insert getopt here, if needed */ 121 while ((c = getopt(argc, argv, "dFS")) != -1) 122 switch(c) { 123 case 'F': 124 sumsize = 2; 125 break; 126 case 'S': 127 /* Dynamically size second-stage boot */ 128 sumsize = 0; 129 break; 130 case 'd': 131 debug = 1; 132 break; 133 default: 134 usage(); 135 } 136 argv += optind; 137 argc -= optind; 138 139 if (argc < 2) 140 usage(); 141 142 ifd = open(argv[0], O_RDONLY, 0); 143 if (ifd < 0) 144 err(1, "Can't open %s", argv[0]); 145 146 image = mmap(0, 65536, PROT_READ, MAP_FILE|MAP_PRIVATE, ifd, 0); 147 if (image == 0) 148 err(1, "Can't mmap %s", argv[1]); 149 150 eh = (Elf32_Ehdr *)image; /* XXX endianness */ 151 152 dprintf(("%04x sections, offset %08x\n", htobe16(eh->e_shnum), htobe32(eh->e_shoff))); 153 if (htobe16(eh->e_type) != ET_REL) 154 errx(1, "%s isn't a relocatable file, type=%d", 155 argv[0], htobe16(eh->e_type)); 156 if (htobe16(eh->e_machine) != EM_68K) 157 errx(1, "%s isn't M68K, machine=%d", argv[0], 158 htobe16(eh->e_machine)); 159 160 /* Calculate sizes from section headers. */ 161 tsz = dsz = bsz = trsz = pcrelsz = r32sz = 0; 162 sh = (Elf32_Shdr *)(image + htobe32(eh->e_shoff)); 163 shstrtab = (char *)(image + htobe32(sh[htobe16(eh->e_shstrndx)].sh_offset)); 164 symtab = NULL; /*XXX*/ 165 strtab = NULL; /*XXX*/ 166 dprintf((" name type flags addr offset size align\n")); 167 for (i = 0; i < htobe16(eh->e_shnum); ++i) { 168 u_int32_t sh_size; 169 170 dprintf( ("%2d: %08x %-16s %08x %08x %08x %08x %08x %08x\n", i, 171 htobe32(sh[i].sh_name), shstrtab + htobe32(sh[i].sh_name), 172 htobe32(sh[i].sh_type), 173 htobe32(sh[i].sh_flags), htobe32(sh[i].sh_addr), 174 htobe32(sh[i].sh_offset), htobe32(sh[i].sh_size), 175 htobe32(sh[i].sh_addralign))); 176 sh_size = (htobe32(sh[i].sh_size) + htobe32(sh[i].sh_addralign) - 1) & 177 -htobe32(sh[i].sh_addralign); 178 /* If section allocates memory, add to text, data, or bss size. */ 179 if (htobe32(sh[i].sh_flags) & SHF_ALLOC) { 180 if (htobe32(sh[i].sh_type) == SHT_PROGBITS) { 181 if (htobe32(sh[i].sh_flags) & SHF_WRITE) 182 dsz += sh_size; 183 else 184 tsz += sh_size; 185 } else 186 bsz += sh_size; 187 /* If it's relocations, add to relocation count */ 188 } else if (htobe32(sh[i].sh_type) == SHT_RELA) { 189 trsz += htobe32(sh[i].sh_size); 190 } 191 /* Check for SHT_REL? */ 192 /* Get symbol table location. */ 193 else if (htobe32(sh[i].sh_type) == SHT_SYMTAB) { 194 symtab = (Elf32_Sym *)(image + htobe32(sh[i].sh_offset)); 195 } else if (strcmp(".strtab", shstrtab + htobe32(sh[i].sh_name)) == 0) { 196 strtab = image + htobe32(sh[i].sh_offset); 197 } 198 } 199 dprintf(("tsz = 0x%x, dsz = 0x%x, bsz = 0x%x, total 0x%x\n", 200 tsz, dsz, bsz, tsz + dsz + bsz)); 201 202 if (trsz == 0) 203 errx(1, "%s has no relocation records.", argv[0]); 204 205 dprintf(("%d relocs\n", trsz/12)); 206 207 if (sumsize == 0) { 208 bbsize = (tsz + dsz + bsz + 511) & ~511; 209 sumsize = bbsize / 512; 210 } 211 212 buffer = malloc(bbsize); 213 relbuf = (u_int32_t *)malloc(bbsize); 214 if (buffer == NULL || relbuf == NULL) 215 err(1, "Unable to allocate memory\n"); 216 217 /* 218 * We have one contiguous area allocated by the ROM to us. 219 */ 220 if (tsz+dsz+bsz > bbsize) 221 errx(1, "%s: resulting image too big %d+%d+%d=%d", argv[0], 222 tsz, dsz, bsz, tsz + dsz + bsz); 223 224 memset(buffer, 0, bbsize); 225 226 /* Allocate and load loadable sections */ 227 sect_offset = (u_int32_t *)malloc(htobe16(eh->e_shnum) * sizeof(u_int32_t)); 228 for (i = 0, l = 0; i < htobe16(eh->e_shnum); ++i) { 229 if (htobe32(sh[i].sh_flags) & SHF_ALLOC) { 230 dprintf(("vaddr 0x%04x size 0x%04x offset 0x%04x section %s\n", 231 l, htobe32(sh[i].sh_size), htobe32(sh[i].sh_offset), 232 shstrtab + htobe32(sh[i].sh_name))); 233 if (htobe32(sh[i].sh_type) == SHT_PROGBITS) 234 memcpy(buffer + l, image + htobe32(sh[i].sh_offset), 235 htobe32(sh[i].sh_size)); 236 sect_offset[i] = l; 237 l += (htobe32(sh[i].sh_size) + htobe32(sh[i].sh_addralign) - 1) & 238 -htobe32(sh[i].sh_addralign); 239 } 240 } 241 242 /* 243 * Hm. This tool REALLY should understand more than one 244 * relocator version. For now, check that the relocator at 245 * the image start does understand what we output. 246 */ 247 relver = htobe32(*(u_int32_t *)(buffer + 4)); 248 switch (relver) { 249 default: 250 errx(1, "%s: unrecognized relocator version %d", 251 argv[0], relver); 252 /*NOTREACHED*/ 253 254 case RELVER_RELATIVE_BYTES: 255 rpo = buffer + bbsize - 1; 256 delta = -1; 257 break; 258 259 case RELVER_RELATIVE_BYTES_FORWARD: 260 rpo = buffer + tsz + dsz; 261 delta = +1; 262 *(u_int16_t *)(buffer + 14) = htobe16(tsz + dsz); 263 break; 264 } 265 266 if (symtab == NULL) 267 errx(1, "No symbol table found"); 268 /* 269 * Link sections and generate relocation data 270 * Nasty: .text, .rodata, .data, .bss sections are not linked 271 * Symbol table values relative to start of sections. 272 * For each relocation entry: 273 * Symbol value needs to be calculated: value + section offset 274 * Image data adjusted to calculated value of symbol + addend 275 * Add relocation table entry for 32-bit relocatable values 276 * PC-relative entries will be absolute and don't need relocation 277 */ 278 undefsyms = 0; 279 for (i = 0; i < htobe16(eh->e_shnum); ++i) { 280 int n; 281 Elf32_Rela *ra; 282 u_int8_t *base; 283 284 if (htobe32(sh[i].sh_type) != SHT_RELA) 285 continue; 286 base = NULL; 287 if (strncmp(shstrtab + htobe32(sh[i].sh_name), ".rela", 5) != 0) 288 err(1, "bad relocation section name %s", shstrtab + 289 htobe32(sh[i].sh_name)); 290 for (n = 0; n < htobe16(eh->e_shnum); ++n) { 291 if (strcmp(shstrtab + htobe32(sh[i].sh_name) + 5, shstrtab + 292 htobe32(sh[n].sh_name)) != 0) 293 continue; 294 base = buffer + sect_offset[n]; 295 break; 296 } 297 if (base == NULL) 298 errx(1, "Can't find section for reloc %s", shstrtab + 299 htobe32(sh[i].sh_name)); 300 ra = (Elf32_Rela *)(image + htobe32(sh[i].sh_offset)); 301 for (n = 0; n < htobe32(sh[i].sh_size); n += sizeof(Elf32_Rela), ++ra) { 302 Elf32_Sym *s; 303 int value; 304 305 s = &symtab[ELF32_R_SYM(htobe32(ra->r_info))]; 306 if (s->st_shndx == ELF_SYM_UNDEFINED) { 307 fprintf(stderr, "Undefined symbol: %s\n", 308 strtab + s->st_name); 309 ++undefsyms; 310 } 311 value = htobe32(ra->r_addend) + eval(s, sect_offset); 312 dprintf(("reloc %04x info %04x (type %d sym %d) add 0x%x val %x\n", 313 htobe32(ra->r_offset), htobe32(ra->r_info), 314 ELF32_R_TYPE(htobe32(ra->r_info)), 315 ELF32_R_SYM(htobe32(ra->r_info)), 316 htobe32(ra->r_addend), value)); 317 switch (ELF32_R_TYPE(htobe32(ra->r_info))) { 318 case R_68K_32: 319 *((u_int32_t *)(base + htobe32(ra->r_offset))) = 320 htobe32(value); 321 relbuf[r32sz++] = (base - buffer) + htobe32(ra->r_offset); 322 break; 323 case R_68K_PC32: 324 ++pcrelsz; 325 *((int32_t *)(base + htobe32(ra->r_offset))) = 326 htobe32(value - htobe32(ra->r_offset)); 327 break; 328 case R_68K_PC16: 329 ++pcrelsz; 330 value -= htobe32(ra->r_offset); 331 if (value < -0x8000 || value > 0x7fff) 332 errx(1, "PC-relative offset out of range: %x\n", 333 value); 334 *((int16_t *)(base + htobe32(ra->r_offset))) = 335 htobe16(value); 336 break; 337 default: 338 errx(1, "Relocation type %d not supported", 339 ELF32_R_TYPE(htobe32(ra->r_info))); 340 } 341 } 342 } 343 dprintf(("%d PC-relative relocations, %d 32-bit relocations\n", 344 pcrelsz, r32sz)); 345 printf("%d absolute reloc%s found, ", r32sz, r32sz==1?"":"s"); 346 347 i = r32sz; 348 if (i > 1) 349 heapsort(relbuf, r32sz, 4, intcmp); 350 351 oldaddr = 0; 352 353 for (--i; i>=0; --i) { 354 dprintf(("0x%04x: ", relbuf[i])); 355 lptr = (u_int32_t *)&buffer[relbuf[i]]; 356 addrdiff = relbuf[i] - oldaddr; 357 dprintf(("(0x%04x, 0x%04x): ", *lptr, addrdiff)); 358 if (addrdiff > 255) { 359 *rpo = 0; 360 if (delta > 0) { 361 ++rpo; 362 *rpo++ = (relbuf[i] >> 8) & 0xff; 363 *rpo++ = relbuf[i] & 0xff; 364 dprintf(("%02x%02x%02x\n", 365 rpo[-3], rpo[-2], rpo[-1])); 366 } else { 367 *--rpo = relbuf[i] & 0xff; 368 *--rpo = (relbuf[i] >> 8) & 0xff; 369 --rpo; 370 dprintf(("%02x%02x%02x\n", 371 rpo[0], rpo[1], rpo[2])); 372 } 373 } else { 374 *rpo = addrdiff; 375 dprintf(("%02x\n", *rpo)); 376 rpo += delta; 377 } 378 379 oldaddr = relbuf[i]; 380 381 if (delta < 0 ? rpo <= buffer+tsz+dsz 382 : rpo >= buffer + bbsize) 383 errx(1, "Relocs don't fit."); 384 } 385 *rpo = 0; rpo += delta; 386 *rpo = 0; rpo += delta; 387 *rpo = 0; rpo += delta; 388 389 printf("using %d bytes, %d bytes remaining.\n", delta > 0 ? 390 rpo-buffer-tsz-dsz : buffer+bbsize-rpo, delta > 0 ? 391 buffer + bbsize - rpo : rpo - buffer - tsz - dsz); 392 /* 393 * RELOCs must fit into the bss area. 394 */ 395 if (delta < 0 ? rpo <= buffer+tsz+dsz 396 : rpo >= buffer + bbsize) 397 errx(1, "Relocs don't fit."); 398 399 if (undefsyms > 0) 400 errx(1, "Undefined symbols referenced"); 401 402 ((u_int32_t *)buffer)[1] = 0; 403 ((u_int32_t *)buffer)[1] = 404 htobe32((0xffffffff - chksum((u_int32_t *)buffer, sumsize * 512 / 4))); 405 406 ofd = open(argv[1], O_CREAT|O_WRONLY, 0644); 407 if (ofd < 0) 408 err(1, "Can't open %s", argv[1]); 409 410 if (write(ofd, buffer, bbsize) != bbsize) 411 err(1, "Writing output file"); 412 413 exit(0); 414 } 415 416 void 417 usage(void) 418 { 419 fprintf(stderr, "Usage: %s [-F] bootprog bootprog.bin\n", 420 progname); 421 exit(1); 422 /* NOTREACHED */ 423 } 424 425 int 426 eval(Elf32_Sym *s, u_int32_t *o) 427 { 428 int value; 429 430 value = htobe32(s->st_value); 431 if (htobe16(s->st_shndx) < 0xf000) 432 value += o[htobe16(s->st_shndx)]; 433 else 434 printf("eval: %x\n", htobe16(s->st_shndx)); 435 return value; 436 } 437
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