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