usr.sbin/btxld/btxld.c

   1 /*
   2  * Copyright (c) 1998 Robert Nordier
   3  * All rights reserved.
   4  *
   5  * Redistribution and use in source and binary forms, with or without
   6  * modification, are permitted provided that the following conditions
   7  * are met:
   8  * 1. Redistributions of source code must retain the above copyright
   9  *    notice, this list of conditions and the following disclaimer.
  10  * 2. Redistributions in binary form must reproduce the above copyright
  11  *    notice, this list of conditions and the following disclaimer in the
  12  *    documentation and/or other materials provided with the distribution.
  13  *
  14  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS``AS IS'' AND
  15  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  16  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
  17  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS
  18  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY,
  19  * OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT
  20  * OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
  21  * BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
  22  * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE
  23  * OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE,
  24  * EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  25  *
  26  * $FreeBSD: src/usr.sbin/btxld/btxld.c,v 1.4 2000/01/04 14:10:36 marcel Exp $
  27  * $DragonFly: src/usr.sbin/btxld/btxld.c,v 1.3 2004/08/19 21:38:30 joerg Exp $
  28  */
  29
  30 #define AOUT_H_FORCE32
  31 #include <sys/param.h>
  32 #include <sys/stat.h>
  33 #include <sys/mman.h>
  34
  35 #include <err.h>
  36 #include <errno.h>
  37 #include <fcntl.h>
  38 #include <stdarg.h>
  39 #include <stdio.h>
  40 #include <stdlib.h>
  41 #include <string.h>
  42 #include <unistd.h>
  43
  44 #include <a.out.h>
  45
  46 #include "btx.h"
  47 #include "elfh.h"
  48
  49 #define BTX_PATH                "/sys/boot/i386/btx"
  50
  51 #define I_LDR   0               /* BTX loader */
  52 #define I_BTX   1               /* BTX kernel */
  53 #define I_CLNT  2               /* Client program */
  54
  55 #define F_BIN   0               /* Binary */
  56 #define F_AOUT  1               /* ZMAGIC a.out */
  57 #define F_ELF   2               /* 32-bit ELF */
  58 #define F_CNT   3               /* Number of formats */
  59
  60 #define IMPURE  1               /* Writable text */
  61 #define MAXU32  0xffffffff      /* Maximum unsigned 32-bit quantity */
  62
  63 #define align(x, y) (((x) + (y) - 1) & ~((y) - 1))
  64
  65 struct hdr {
  66     uint32_t fmt;               /* Format */
  67     uint32_t flags;             /* Bit flags */
  68     uint32_t size;              /* Size of file */
  69     uint32_t text;              /* Size of text segment */
  70     uint32_t data;              /* Size of data segment */
  71     uint32_t bss;               /* Size of bss segment */
  72     uint32_t org;               /* Program origin */
  73     uint32_t entry;             /* Program entry point */
  74 };
  75
  76 static const char *const fmtlist[] = {"bin", "aout", "elf"};
  77
  78 static const char binfo[] =
  79     "kernel: ver=%u.%02u size=%x load=%x entry=%x map=%uM "
  80     "pgctl=%x:%x\n";
  81 static const char cinfo[] =
  82     "client: fmt=%s size=%x text=%x data=%x bss=%x entry=%x\n";
  83 static const char oinfo[] =
  84     "output: fmt=%s size=%x text=%x data=%x org=%x entry=%x\n";
  85
  86 static const char *lname =
  87     BTX_PATH "/btxldr/btxldr";  /* BTX loader */
  88 static const char *bname =
  89     BTX_PATH "/btx/btx";        /* BTX kernel */
  90 static const char *oname =
  91     "a.out";                    /* Output filename */
  92
  93 static int ppage = -1;          /* First page present */
  94 static int wpage = -1;          /* First page writable */
  95
  96 static unsigned int format;     /* Output format */
  97
  98 static uint32_t centry;         /* Client entry address */
  99 static uint32_t lentry;         /* Loader entry address */
 100
 101 static int Eflag;               /* Client entry option */
 102
 103 static int quiet;               /* Inhibit warnings */
 104 static int verbose;             /* Display information */
 105
 106 static const char *tname;       /* Temporary output file */
 107 static const char *fname;       /* Current input file */
 108
 109 static void cleanup(void);
 110 static void btxld(const char *);
 111 static void getbtx(int, struct btx_hdr *);
 112 static void gethdr(int, struct hdr *);
 113 static void puthdr(int, struct hdr *);
 114 static void copy(int, int, size_t, off_t);
 115 static size_t readx(int, void *, size_t, off_t);
 116 static void writex(int, const void *, size_t);
 117 static void seekx(int, off_t);
 118 static unsigned int optfmt(const char *);
 119 static uint32_t optaddr(const char *);
 120 static int optpage(const char *, int);
 121 static void Warn(const char *, const char *, ...);
 122 static void usage(void);
 123
 124 /*
 125  * A link editor for BTX clients.
 126  */
 127 int
 128 main(int argc, char *argv[])
 129 {
 130     int c;
 131
 132     while ((c = getopt(argc, argv, "qvb:E:e:f:l:o:P:W:")) != -1)
 133         switch (c) {
 134         case 'q':
 135             quiet = 1;
 136             break;
 137         case 'v':
 138             verbose = 1;
 139             break;
 140         case 'b':
 141             bname = optarg;
 142             break;
 143         case 'E':
 144             centry = optaddr(optarg);
 145             Eflag = 1;
 146             break;
 147         case 'e':
 148             lentry = optaddr(optarg);
 149             break;
 150         case 'f':
 151             format = optfmt(optarg);
 152             break;
 153         case 'l':
 154             lname = optarg;
 155             break;
 156         case 'o':
 157             oname = optarg;
 158             break;
 159         case 'P':
 160             ppage = optpage(optarg, 1);
 161             break;
 162         case 'W':
 163             wpage = optpage(optarg, BTX_MAXCWR);
 164             break;
 165         default:
 166             usage();
 167         }
 168     argc -= optind;
 169     argv += optind;
 170     if (argc != 1)
 171         usage();
 172     atexit(cleanup);
 173     btxld(*argv);
 174     return 0;
 175 }
 176
 177 /*
 178  * Clean up after errors.
 179  */
 180 static void
 181 cleanup(void)
 182 {
 183     if (tname)
 184         remove(tname);
 185 }
 186
 187 /*
 188  * Read the input files; write the output file; display information.
 189  */
 190 static void
 191 btxld(const char *iname)
 192 {
 193     char name[FILENAME_MAX];
 194     struct btx_hdr btx;
 195     struct hdr ihdr, ohdr;
 196     unsigned int ldr_size, cwr;
 197     int fdi[3], fdo, i;
 198
 199     ldr_size = 0;
 200
 201     for (i = I_LDR; i <= I_CLNT; i++) {
 202         fname = i == I_LDR ? lname : i == I_BTX ? bname : iname;
 203         if ((fdi[i] = open(fname, O_RDONLY)) == -1)
 204             err(2, "%s", fname);
 205         switch (i) {
 206         case I_LDR:
 207             gethdr(fdi[i], &ihdr);
 208             if (ihdr.fmt != F_BIN)
 209                 Warn(fname, "Loader format is %s; processing as %s",
 210                      fmtlist[ihdr.fmt], fmtlist[F_BIN]);
 211             ldr_size = ihdr.size;
 212             break;
 213         case I_BTX:
 214             getbtx(fdi[i], &btx);
 215             break;
 216         case I_CLNT:
 217             gethdr(fdi[i], &ihdr);
 218             if (ihdr.org && ihdr.org != BTX_PGSIZE)
 219                 Warn(fname,
 220                      "Client origin is 0x%x; expecting 0 or 0x%x",
 221                      ihdr.org, BTX_PGSIZE);
 222         }
 223     }
 224     memset(&ohdr, 0, sizeof(ohdr));
 225     ohdr.fmt = format;
 226     ohdr.text = ldr_size;
 227     ohdr.data = btx.btx_textsz + ihdr.size;
 228     ohdr.org = lentry;
 229     ohdr.entry = lentry;
 230     cwr = 0;
 231     if (wpage > 0 || (wpage == -1 && !(ihdr.flags & IMPURE))) {
 232         if (wpage > 0)
 233             cwr = wpage;
 234         else {
 235             cwr = howmany(ihdr.text, BTX_PGSIZE);
 236             if (cwr > BTX_MAXCWR)
 237                 cwr = BTX_MAXCWR;
 238         }
 239     }
 240     if (ppage > 0 || (ppage && wpage && ihdr.org >= BTX_PGSIZE)) {
 241         btx.btx_flags |= BTX_MAPONE;
 242         if (!cwr)
 243             cwr++;
 244     }
 245     btx.btx_pgctl -= cwr;
 246     btx.btx_entry = Eflag ? centry : ihdr.entry;
 247     if (snprintf(name, sizeof(name), "%s.tmp", oname) >= sizeof(name))
 248         errx(2, "%s: Filename too long", oname);
 249     if ((fdo = open(name, O_CREAT | O_TRUNC | O_WRONLY, 0666)) == -1)
 250         err(2, "%s", name);
 251     if (!(tname = strdup(name)))
 252         err(2, NULL);
 253     puthdr(fdo, &ohdr);
 254     for (i = I_LDR; i <= I_CLNT; i++) {
 255         fname = i == I_LDR ? lname : i == I_BTX ? bname : iname;
 256         switch (i) {
 257         case I_LDR:
 258             copy(fdi[i], fdo, ldr_size, 0);
 259             seekx(fdo, ohdr.size += ohdr.text);
 260             break;
 261         case I_BTX:
 262             writex(fdo, &btx, sizeof(btx));
 263             copy(fdi[i], fdo, btx.btx_textsz - sizeof(btx),
 264                  sizeof(btx));
 265             break;
 266         case I_CLNT:
 267             copy(fdi[i], fdo, ihdr.size, 0);
 268             if (ftruncate(fdo, ohdr.size += ohdr.data))
 269                 err(2, "%s", tname);
 270         }
 271         if (close(fdi[i]))
 272             err(2, "%s", fname);
 273     }
 274     if (close(fdo))
 275         err(2, "%s", tname);
 276     if (rename(tname, oname))
 277         err(2, "%s: Can't rename to %s", tname, oname);
 278     tname = NULL;
 279     if (verbose) {
 280         printf(binfo, btx.btx_majver, btx.btx_minver, btx.btx_textsz,
 281                BTX_ORIGIN(btx), BTX_ENTRY(btx), BTX_MAPPED(btx) *
 282                BTX_PGSIZE / 0x100000, !!(btx.btx_flags & BTX_MAPONE),
 283                BTX_MAPPED(btx) - btx.btx_pgctl - BTX_PGBASE /
 284                BTX_PGSIZE - BTX_MAPPED(btx) * 4 / BTX_PGSIZE);
 285         printf(cinfo, fmtlist[ihdr.fmt], ihdr.size, ihdr.text,
 286                ihdr.data, ihdr.bss, ihdr.entry);
 287         printf(oinfo, fmtlist[ohdr.fmt], ohdr.size, ohdr.text,
 288                ohdr.data, ohdr.org, ohdr.entry);
 289     }
 290 }
 291
 292 /*
 293  * Read BTX file header.
 294  */
 295 static void
 296 getbtx(int fd, struct btx_hdr * btx)
 297 {
 298     if (readx(fd, btx, sizeof(*btx), 0) != sizeof(*btx) ||
 299         btx->btx_magic[0] != BTX_MAG0 ||
 300         btx->btx_magic[1] != BTX_MAG1 ||
 301         btx->btx_magic[2] != BTX_MAG2)
 302         errx(1, "%s: Not a BTX kernel", fname);
 303 }
 304
 305 /*
 306  * Get file size and read a.out or ELF header.
 307  */
 308 static void
 309 gethdr(int fd, struct hdr *hdr)
 310 {
 311     struct stat sb;
 312     const struct exec *ex;
 313     const Elf32_Ehdr *ee;
 314     const Elf32_Phdr *ep;
 315     void *p;
 316     unsigned int fmt, x, n, i;
 317
 318     memset(hdr, 0, sizeof(*hdr));
 319     if (fstat(fd, &sb))
 320         err(2, "%s", fname);
 321     if (sb.st_size > MAXU32)
 322         errx(1, "%s: Too big", fname);
 323     hdr->size = sb.st_size;
 324     if ((p = mmap(NULL, hdr->size, PROT_READ, MAP_SHARED, fd,
 325                   0)) == MAP_FAILED)
 326         err(2, "%s", fname);
 327     for (fmt = F_CNT - 1; !hdr->fmt && fmt; fmt--)
 328         switch (fmt) {
 329         case F_AOUT:
 330             ex = p;
 331             if (hdr->size >= sizeof(struct exec) && !N_BADMAG(*ex)) {
 332                 hdr->fmt = fmt;
 333                 x = N_GETMAGIC(*ex);
 334                 if (x == OMAGIC || x == NMAGIC) {
 335                     if (x == NMAGIC)
 336                         Warn(fname, "Treating %s NMAGIC as OMAGIC",
 337                              fmtlist[fmt]);
 338                     hdr->flags |= IMPURE;
 339                 }
 340                 hdr->text = ex->a_text;
 341                 hdr->data = ex->a_data;
 342                 hdr->bss = ex->a_bss;
 343                 hdr->entry = ex->a_entry;
 344                 if (ex->a_entry >= BTX_PGSIZE)
 345                     hdr->org = BTX_PGSIZE;
 346             }
 347             break;
 348         case F_ELF:
 349             ee = p;
 350             if (hdr->size >= sizeof(Elf32_Ehdr) && IS_ELF(*ee)) {
 351                 hdr->fmt = fmt;
 352                 for (n = i = 0; i < ee->e_phnum; i++) {
 353                     ep = (void *)((uint8_t *)p + ee->e_phoff +
 354                                   ee->e_phentsize * i);
 355                     if (ep->p_type == PT_LOAD)
 356                         switch (n++) {
 357                         case 0:
 358                             hdr->text = ep->p_filesz;
 359                             hdr->org = ep->p_paddr;
 360                             if (ep->p_flags & PF_W)
 361                                 hdr->flags |= IMPURE;
 362                             break;
 363                         case 1:
 364                             hdr->data = ep->p_filesz;
 365                             hdr->bss = ep->p_memsz - ep->p_filesz;
 366                             break;
 367                         case 2:
 368                             Warn(fname,
 369                                  "Ignoring extra %s PT_LOAD segments",
 370                                  fmtlist[fmt]);
 371                         }
 372                 }
 373                 hdr->entry = ee->e_entry;
 374             }
 375         }
 376     if (munmap(p, hdr->size))
 377         err(2, "%s", fname);
 378 }
 379
 380 /*
 381  * Write a.out or ELF header.
 382  */
 383 static void
 384 puthdr(int fd, struct hdr *hdr)
 385 {
 386     struct exec ex;
 387     struct elfh eh;
 388
 389     switch (hdr->fmt) {
 390     case F_AOUT:
 391         memset(&ex, 0, sizeof(ex));
 392         N_SETMAGIC(ex, ZMAGIC, MID_ZERO, 0);
 393         hdr->text = N_ALIGN(ex, hdr->text);
 394         ex.a_text = hdr->text;
 395         hdr->data = N_ALIGN(ex, hdr->data);
 396         ex.a_data = hdr->data;
 397         ex.a_entry = hdr->entry;
 398         writex(fd, &ex, sizeof(ex));
 399         hdr->size = N_ALIGN(ex, sizeof(ex));
 400         seekx(fd, hdr->size);
 401         break;
 402     case F_ELF:
 403         eh = elfhdr;
 404         eh.e.e_entry = hdr->entry;
 405         eh.p[0].p_vaddr = eh.p[0].p_paddr = hdr->org;
 406         eh.p[0].p_filesz = eh.p[0].p_memsz = hdr->text;
 407         eh.p[1].p_offset = eh.p[0].p_offset + eh.p[0].p_filesz;
 408         eh.p[1].p_vaddr = eh.p[1].p_paddr = align(eh.p[0].p_paddr +
 409                                                   eh.p[0].p_memsz, 4);
 410         eh.p[1].p_filesz = eh.p[1].p_memsz = hdr->data;
 411         eh.sh[2].sh_addr = eh.p[0].p_vaddr;
 412         eh.sh[2].sh_offset = eh.p[0].p_offset;
 413         eh.sh[2].sh_size = eh.p[0].p_filesz;
 414         eh.sh[3].sh_addr = eh.p[1].p_vaddr;
 415         eh.sh[3].sh_offset = eh.p[1].p_offset;
 416         eh.sh[3].sh_size = eh.p[1].p_filesz;
 417         writex(fd, &eh, sizeof(eh));
 418         hdr->size = sizeof(eh);
 419     }
 420 }
 421
 422 /*
 423  * Safe copy from input file to output file.
 424  */
 425 static void
 426 copy(int fdi, int fdo, size_t nbyte, off_t offset)
 427 {
 428     char buf[8192];
 429     size_t n;
 430
 431     while (nbyte) {
 432         if ((n = sizeof(buf)) > nbyte)
 433             n = nbyte;
 434         if (readx(fdi, buf, n, offset) != n)
 435             errx(2, "%s: Short read", fname);
 436         writex(fdo, buf, n);
 437         nbyte -= n;
 438         offset = -1;
 439     }
 440 }
 441
 442 /*
 443  * Safe read from input file.
 444  */
 445 static size_t
 446 readx(int fd, void *buf, size_t nbyte, off_t offset)
 447 {
 448     ssize_t n;
 449
 450     if (offset != -1 && lseek(fd, offset, SEEK_SET) != offset)
 451         err(2, "%s", fname);
 452     if ((n = read(fd, buf, nbyte)) == -1)
 453         err(2, "%s", fname);
 454     return n;
 455 }
 456
 457 /*
 458  * Safe write to output file.
 459  */
 460 static void
 461 writex(int fd, const void *buf, size_t nbyte)
 462 {
 463     ssize_t n;
 464
 465     if ((n = write(fd, buf, nbyte)) == -1)
 466         err(2, "%s", tname);
 467     if (n != nbyte)
 468         errx(2, "%s: Short write", tname);
 469 }
 470
 471 /*
 472  * Safe seek in output file.
 473  */
 474 static void
 475 seekx(int fd, off_t offset)
 476 {
 477     if (lseek(fd, offset, SEEK_SET) != offset)
 478         err(2, "%s", tname);
 479 }
 480
 481 /*
 482  * Convert an option argument to a format code.
 483  */
 484 static unsigned int
 485 optfmt(const char *arg)
 486 {
 487     unsigned int i;
 488
 489     for (i = 0; i < F_CNT && strcmp(arg, fmtlist[i]); i++);
 490     if (i == F_CNT)
 491         errx(1, "%s: Unknown format", arg);
 492     return i;
 493 }
 494
 495 /*
 496  * Convert an option argument to an address.
 497  */
 498 static uint32_t
 499 optaddr(const char *arg)
 500 {
 501     char *s;
 502     unsigned long x;
 503
 504     errno = 0;
 505     x = strtoul(arg, &s, 0);
 506     if (errno || !*arg || *s || x > MAXU32)
 507         errx(1, "%s: Illegal address", arg);
 508     return x;
 509 }
 510
 511 /*
 512  * Convert an option argument to a page number.
 513  */
 514 static int
 515 optpage(const char *arg, int hi)
 516 {
 517     char *s;
 518     long x;
 519
 520     errno = 0;
 521     x = strtol(arg, &s, 0);
 522     if (errno || !*arg || *s || x < 0 || x > hi)
 523         errx(1, "%s: Illegal page number", arg);
 524     return x;
 525 }
 526
 527 /*
 528  * Display a warning.
 529  */
 530 static void
 531 Warn(const char *locus, const char *fmt, ...)
 532 {
 533     va_list ap;
 534     char *s;
 535
 536     if (!quiet) {
 537         asprintf(&s, "%s: Warning: %s", locus, fmt);
 538         va_start(ap, fmt);
 539         vwarnx(s, ap);
 540         va_end(ap);
 541         free(s);
 542     }
 543 }
 544
 545 /*
 546  * Display usage information.
 547  */
 548 static void
 549 usage(void)
 550 {
 551     fprintf(stderr, "%s\n%s\n",
 552     "usage: btxld [-qv] [-b file] [-E address] [-e address] [-f format]",
 553     "             [-l file] [-o filename] [-P page] [-W page] file");
 554     exit(1);
 555 }