elf2bb.c revision 1.12
1 /* $NetBSD: elf2bb.c,v 1.12 2006/01/24 20:04:05 is Exp $ */ 2 3 /*- 4 * Copyright (c) 1996,2006 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 uint32_t tmp32; 117 uint16_t tmp16; 118 119 progname = argv[0]; 120 121 /* insert getopt here, if needed */ 122 while ((c = getopt(argc, argv, "dFS")) != -1) 123 switch(c) { 124 case 'F': 125 sumsize = 2; 126 break; 127 case 'S': 128 /* Dynamically size second-stage boot */ 129 sumsize = 0; 130 break; 131 case 'd': 132 debug = 1; 133 break; 134 default: 135 usage(); 136 } 137 argv += optind; 138 argc -= optind; 139 140 if (argc < 2) 141 usage(); 142 143 ifd = open(argv[0], O_RDONLY, 0); 144 if (ifd < 0) 145 err(1, "Can't open %s", argv[0]); 146 147 image = mmap(0, 65536, PROT_READ, MAP_FILE|MAP_PRIVATE, ifd, 0); 148 if (image == 0) 149 err(1, "Can't mmap %s", argv[1]); 150 151 eh = (Elf32_Ehdr *)image; /* XXX endianness */ 152 153 dprintf(("%04x sections, offset %08x\n", htobe16(eh->e_shnum), htobe32(eh->e_shoff))); 154 if (htobe16(eh->e_type) != ET_REL) 155 errx(1, "%s isn't a relocatable file, type=%d", 156 argv[0], htobe16(eh->e_type)); 157 if (htobe16(eh->e_machine) != EM_68K) 158 errx(1, "%s isn't M68K, machine=%d", argv[0], 159 htobe16(eh->e_machine)); 160 161 /* Calculate sizes from section headers. */ 162 tsz = dsz = bsz = trsz = pcrelsz = r32sz = 0; 163 sh = (Elf32_Shdr *)(image + htobe32(eh->e_shoff)); 164 shstrtab = (char *)(image + htobe32(sh[htobe16(eh->e_shstrndx)].sh_offset)); 165 symtab = NULL; /*XXX*/ 166 strtab = NULL; /*XXX*/ 167 dprintf((" name type flags addr offset size align\n")); 168 for (i = 0; i < htobe16(eh->e_shnum); ++i) { 169 u_int32_t sh_size; 170 171 dprintf( ("%2d: %08x %-16s %08x %08x %08x %08x %08x %08x\n", i, 172 htobe32(sh[i].sh_name), shstrtab + htobe32(sh[i].sh_name), 173 htobe32(sh[i].sh_type), 174 htobe32(sh[i].sh_flags), htobe32(sh[i].sh_addr), 175 htobe32(sh[i].sh_offset), htobe32(sh[i].sh_size), 176 htobe32(sh[i].sh_addralign))); 177 sh_size = (htobe32(sh[i].sh_size) + htobe32(sh[i].sh_addralign) - 1) & 178 -htobe32(sh[i].sh_addralign); 179 /* If section allocates memory, add to text, data, or bss size. */ 180 if (htobe32(sh[i].sh_flags) & SHF_ALLOC) { 181 if (htobe32(sh[i].sh_type) == SHT_PROGBITS) { 182 if (htobe32(sh[i].sh_flags) & SHF_WRITE) 183 dsz += sh_size; 184 else 185 tsz += sh_size; 186 } else 187 bsz += sh_size; 188 /* If it's relocations, add to relocation count */ 189 } else if (htobe32(sh[i].sh_type) == SHT_RELA) { 190 trsz += htobe32(sh[i].sh_size); 191 } 192 /* Check for SHT_REL? */ 193 /* Get symbol table location. */ 194 else if (htobe32(sh[i].sh_type) == SHT_SYMTAB) { 195 symtab = (Elf32_Sym *)(image + htobe32(sh[i].sh_offset)); 196 } else if (strcmp(".strtab", shstrtab + htobe32(sh[i].sh_name)) == 0) { 197 strtab = image + htobe32(sh[i].sh_offset); 198 } 199 } 200 dprintf(("tsz = 0x%x, dsz = 0x%x, bsz = 0x%x, total 0x%x\n", 201 tsz, dsz, bsz, tsz + dsz + bsz)); 202 203 if (trsz == 0) 204 errx(1, "%s has no relocation records.", argv[0]); 205 206 dprintf(("%d relocs\n", trsz/12)); 207 208 if (sumsize == 0) { 209 /* 210 * XXX overly cautious, but this guarantees that 16bit 211 * pc offsets and our relocs always work. 212 */ 213 bbsize = 32768; 214 if (bbsize < (tsz + dsz + bsz)) { 215 err(1, "%s: too big.", argv[0]); 216 } 217 sumsize = bbsize / 512; 218 } 219 220 buffer = malloc(bbsize); 221 relbuf = (u_int32_t *)malloc(bbsize); 222 if (buffer == NULL || relbuf == NULL) 223 err(1, "Unable to allocate memory\n"); 224 225 /* 226 * We have one contiguous area allocated by the ROM to us. 227 */ 228 if (tsz+dsz+bsz > bbsize) 229 errx(1, "%s: resulting image too big %d+%d+%d=%d", argv[0], 230 tsz, dsz, bsz, tsz + dsz + bsz); 231 232 memset(buffer, 0, bbsize); 233 234 /* Allocate and load loadable sections */ 235 sect_offset = (u_int32_t *)malloc(htobe16(eh->e_shnum) * sizeof(u_int32_t)); 236 for (i = 0, l = 0; i < htobe16(eh->e_shnum); ++i) { 237 if (htobe32(sh[i].sh_flags) & SHF_ALLOC) { 238 dprintf(("vaddr 0x%04x size 0x%04x offset 0x%04x section %s\n", 239 l, htobe32(sh[i].sh_size), htobe32(sh[i].sh_offset), 240 shstrtab + htobe32(sh[i].sh_name))); 241 if (htobe32(sh[i].sh_type) == SHT_PROGBITS) 242 memcpy(buffer + l, image + htobe32(sh[i].sh_offset), 243 htobe32(sh[i].sh_size)); 244 sect_offset[i] = l; 245 l += (htobe32(sh[i].sh_size) + htobe32(sh[i].sh_addralign) - 1) & 246 -htobe32(sh[i].sh_addralign); 247 } 248 } 249 250 /* 251 * Hm. This tool REALLY should understand more than one 252 * relocator version. For now, check that the relocator at 253 * the image start does understand what we output. 254 */ 255 relver = htobe32(*(u_int32_t *)(buffer + 4)); 256 switch (relver) { 257 default: 258 errx(1, "%s: unrecognized relocator version %d", 259 argv[0], relver); 260 /*NOTREACHED*/ 261 262 case RELVER_RELATIVE_BYTES: 263 rpo = buffer + bbsize - 1; 264 delta = -1; 265 break; 266 267 case RELVER_RELATIVE_BYTES_FORWARD: 268 rpo = buffer + tsz + dsz; 269 delta = +1; 270 *(u_int16_t *)(buffer + 14) = htobe16(tsz + dsz); 271 break; 272 } 273 274 if (symtab == NULL) 275 errx(1, "No symbol table found"); 276 /* 277 * Link sections and generate relocation data 278 * Nasty: .text, .rodata, .data, .bss sections are not linked 279 * Symbol table values relative to start of sections. 280 * For each relocation entry: 281 * Symbol value needs to be calculated: value + section offset 282 * Image data adjusted to calculated value of symbol + addend 283 * Add relocation table entry for 32-bit relocatable values 284 * PC-relative entries will be absolute and don't need relocation 285 */ 286 undefsyms = 0; 287 for (i = 0; i < htobe16(eh->e_shnum); ++i) { 288 int n; 289 Elf32_Rela *ra; 290 u_int8_t *base; 291 292 if (htobe32(sh[i].sh_type) != SHT_RELA) 293 continue; 294 base = NULL; 295 if (strncmp(shstrtab + htobe32(sh[i].sh_name), ".rela", 5) != 0) 296 err(1, "bad relocation section name %s", shstrtab + 297 htobe32(sh[i].sh_name)); 298 for (n = 0; n < htobe16(eh->e_shnum); ++n) { 299 if (strcmp(shstrtab + htobe32(sh[i].sh_name) + 5, shstrtab + 300 htobe32(sh[n].sh_name)) != 0) 301 continue; 302 base = buffer + sect_offset[n]; 303 break; 304 } 305 if (base == NULL) 306 errx(1, "Can't find section for reloc %s", shstrtab + 307 htobe32(sh[i].sh_name)); 308 ra = (Elf32_Rela *)(image + htobe32(sh[i].sh_offset)); 309 for (n = 0; n < htobe32(sh[i].sh_size); n += sizeof(Elf32_Rela), ++ra) { 310 Elf32_Sym *s; 311 int value; 312 313 s = &symtab[ELF32_R_SYM(htobe32(ra->r_info))]; 314 if (s->st_shndx == ELF_SYM_UNDEFINED) { 315 fprintf(stderr, "Undefined symbol: %s\n", 316 strtab + s->st_name); 317 ++undefsyms; 318 } 319 value = htobe32(ra->r_addend) + eval(s, sect_offset); 320 dprintf(("reloc %04x info %04x (type %d sym %d) add 0x%x val %x\n", 321 htobe32(ra->r_offset), htobe32(ra->r_info), 322 ELF32_R_TYPE(htobe32(ra->r_info)), 323 ELF32_R_SYM(htobe32(ra->r_info)), 324 htobe32(ra->r_addend), value)); 325 switch (ELF32_R_TYPE(htobe32(ra->r_info))) { 326 case R_68K_32: 327 tmp32 = htobe32(value); 328 memcpy(base + htobe32(ra->r_offset), &tmp32, 329 sizeof(tmp32)); 330 relbuf[r32sz++] = (base - buffer) + htobe32(ra->r_offset); 331 break; 332 case R_68K_PC32: 333 ++pcrelsz; 334 tmp32 = htobe32(value - htobe32(ra->r_offset)); 335 memcpy(base + htobe32(ra->r_offset), &tmp32, 336 sizeof(tmp32)); 337 break; 338 case R_68K_PC16: 339 ++pcrelsz; 340 value -= htobe32(ra->r_offset); 341 if (value < -0x8000 || value > 0x7fff) 342 errx(1, "PC-relative offset out of range: %x\n", 343 value); 344 tmp16 = htobe16(value); 345 memcpy(base + htobe32(ra->r_offset), &tmp16, 346 sizeof(tmp16)); 347 break; 348 default: 349 errx(1, "Relocation type %d not supported", 350 ELF32_R_TYPE(htobe32(ra->r_info))); 351 } 352 } 353 } 354 dprintf(("%d PC-relative relocations, %d 32-bit relocations\n", 355 pcrelsz, r32sz)); 356 printf("%d absolute reloc%s found, ", r32sz, r32sz==1?"":"s"); 357 358 i = r32sz; 359 if (i > 1) 360 heapsort(relbuf, r32sz, 4, intcmp); 361 362 oldaddr = 0; 363 364 for (--i; i>=0; --i) { 365 dprintf(("0x%04x: ", relbuf[i])); 366 lptr = (u_int32_t *)&buffer[relbuf[i]]; 367 addrdiff = relbuf[i] - oldaddr; 368 dprintf(("(0x%04x, 0x%04x): ", *lptr, addrdiff)); 369 if (addrdiff > 255) { 370 *rpo = 0; 371 if (delta > 0) { 372 ++rpo; 373 *rpo++ = (relbuf[i] >> 8) & 0xff; 374 *rpo++ = relbuf[i] & 0xff; 375 dprintf(("%02x%02x%02x\n", 376 rpo[-3], rpo[-2], rpo[-1])); 377 } else { 378 *--rpo = relbuf[i] & 0xff; 379 *--rpo = (relbuf[i] >> 8) & 0xff; 380 --rpo; 381 dprintf(("%02x%02x%02x\n", 382 rpo[0], rpo[1], rpo[2])); 383 } 384 } else { 385 *rpo = addrdiff; 386 dprintf(("%02x\n", *rpo)); 387 rpo += delta; 388 } 389 390 oldaddr = relbuf[i]; 391 392 if (delta < 0 ? rpo <= buffer+tsz+dsz 393 : rpo >= buffer + bbsize) 394 errx(1, "Relocs don't fit."); 395 } 396 *rpo = 0; rpo += delta; 397 *rpo = 0; rpo += delta; 398 *rpo = 0; rpo += delta; 399 400 printf("using %d bytes, %d bytes remaining.\n", delta > 0 ? 401 rpo-buffer-tsz-dsz : buffer+bbsize-rpo, delta > 0 ? 402 buffer + bbsize - rpo : rpo - buffer - tsz - dsz); 403 /* 404 * RELOCs must fit into the bss area. 405 */ 406 if (delta < 0 ? rpo <= buffer+tsz+dsz 407 : rpo >= buffer + bbsize) 408 errx(1, "Relocs don't fit."); 409 410 if (undefsyms > 0) 411 errx(1, "Undefined symbols referenced"); 412 413 ((u_int32_t *)buffer)[1] = 0; 414 ((u_int32_t *)buffer)[1] = 415 htobe32((0xffffffff - chksum((u_int32_t *)buffer, sumsize * 512 / 4))); 416 417 ofd = open(argv[1], O_CREAT|O_WRONLY, 0644); 418 if (ofd < 0) 419 err(1, "Can't open %s", argv[1]); 420 421 if (write(ofd, buffer, bbsize) != bbsize) 422 err(1, "Writing output file"); 423 424 exit(0); 425 } 426 427 void 428 usage(void) 429 { 430 fprintf(stderr, "Usage: %s [-F] bootprog bootprog.bin\n", 431 progname); 432 exit(1); 433 /* NOTREACHED */ 434 } 435 436 int 437 eval(Elf32_Sym *s, u_int32_t *o) 438 { 439 int value; 440 441 value = htobe32(s->st_value); 442 if (htobe16(s->st_shndx) < 0xf000) 443 value += o[htobe16(s->st_shndx)]; 444 else 445 printf("eval: %x\n", htobe16(s->st_shndx)); 446 return value; 447 } 448
Indexes created Tue Oct 14 21:09:58 GMT 2025