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  */
  28
  29 #define AOUT_H_FORCE32
  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 struct hdr {
  63     uint32_t fmt;               /* Format */
  64     uint32_t flags;             /* Bit flags */
  65     uint32_t size;              /* Size of file */
  66     uint32_t text;              /* Size of text segment */
  67     uint32_t data;              /* Size of data segment */
  68     uint32_t bss;               /* Size of bss segment */
  69     uint32_t org;               /* Program origin */
  70     uint32_t entry;             /* Program entry point */
  71 };
  72
  73 static const char *const fmtlist[] = {"bin", "aout", "elf"};
  74
  75 static const char binfo[] =
  76     "kernel: ver=%u.%02u size=%x load=%x entry=%x map=%uM "
  77     "pgctl=%x:%x\n";
  78 static const char cinfo[] =
  79     "client: fmt=%s size=%x text=%x data=%x bss=%x entry=%x\n";
  80 static const char oinfo[] =
  81     "output: fmt=%s size=%x text=%x data=%x org=%x entry=%x\n";
  82
  83 static const char *lname =
  84     BTX_PATH "/btxldr/btxldr";  /* BTX loader */
  85 static const char *bname =
  86     BTX_PATH "/btx/btx";        /* BTX kernel */
  87 static const char *oname =
  88     "a.out";                    /* Output filename */
  89
  90 static int ppage = -1;          /* First page present */
  91 static int wpage = -1;          /* First page writable */
  92
  93 static unsigned int format;     /* Output format */
  94
  95 static uint32_t centry;         /* Client entry address */
  96 static uint32_t lentry;         /* Loader entry address */
  97
  98 static int Eflag;               /* Client entry option */
  99
 100 static int quiet;               /* Inhibit warnings */
 101 static int verbose;             /* Display information */
 102
 103 static const char *tname;       /* Temporary output file */
 104 static const char *fname;       /* Current input file */
 105
 106 static void cleanup(void);
 107 static void btxld(const char *);
 108 static void getbtx(int, struct btx_hdr *);
 109 static void gethdr(int, struct hdr *);
 110 static void puthdr(int, struct hdr *);
 111 static void copy(int, int, size_t, off_t);
 112 static size_t readx(int, void *, size_t, off_t);
 113 static void writex(int, const void *, size_t);
 114 static void seekx(int, off_t);
 115 static unsigned int optfmt(const char *);
 116 static uint32_t optaddr(const char *);
 117 static int optpage(const char *, int);
 118 static void Warn(const char *, const char *, ...) __printflike(2, 3);
 119 static void usage(void);
 120
 121 /*
 122  * A link editor for BTX clients.
 123  */
 124 int
 125 main(int argc, char *argv[])
 126 {
 127     int c;
 128
 129     while ((c = getopt(argc, argv, "qvb:E:e:f:l:o:P:W:")) != -1)
 130         switch (c) {
 131         case 'q':
 132             quiet = 1;
 133             break;
 134         case 'v':
 135             verbose = 1;
 136             break;
 137         case 'b':
 138             bname = optarg;
 139             break;
 140         case 'E':
 141             centry = optaddr(optarg);
 142             Eflag = 1;
 143             break;
 144         case 'e':
 145             lentry = optaddr(optarg);
 146             break;
 147         case 'f':
 148             format = optfmt(optarg);
 149             break;
 150         case 'l':
 151             lname = optarg;
 152             break;
 153         case 'o':
 154             oname = optarg;
 155             break;
 156         case 'P':
 157             ppage = optpage(optarg, 1);
 158             break;
 159         case 'W':
 160             wpage = optpage(optarg, BTX_MAXCWR);
 161             break;
 162         default:
 163             usage();
 164         }
 165     argc -= optind;
 166     argv += optind;
 167     if (argc != 1)
 168         usage();
 169     atexit(cleanup);
 170     btxld(*argv);
 171     return 0;
 172 }
 173
 174 /*
 175  * Clean up after errors.
 176  */
 177 static void
 178 cleanup(void)
 179 {
 180     if (tname)
 181         remove(tname);
 182 }
 183
 184 /*
 185  * Read the input files; write the output file; display information.
 186  */
 187 static void
 188 btxld(const char *iname)
 189 {
 190     char name[FILENAME_MAX];
 191     struct btx_hdr btx;
 192     struct hdr ihdr, ohdr;
 193     unsigned int ldr_size, cwr;
 194     int fdi[3], fdo, i;
 195
 196     ldr_size = 0;
 197
 198     for (i = I_LDR; i <= I_CLNT; i++) {
 199         fname = i == I_LDR ? lname : i == I_BTX ? bname : iname;
 200         if ((fdi[i] = open(fname, O_RDONLY)) == -1)
 201             err(2, "%s", fname);
 202         switch (i) {
 203         case I_LDR:
 204             gethdr(fdi[i], &ihdr);
 205             if (ihdr.fmt != F_BIN)
 206                 Warn(fname, "Loader format is %s; processing as %s",
 207                      fmtlist[ihdr.fmt], fmtlist[F_BIN]);
 208             ldr_size = ihdr.size;
 209             break;
 210         case I_BTX:
 211             getbtx(fdi[i], &btx);
 212             break;
 213         case I_CLNT:
 214             gethdr(fdi[i], &ihdr);
 215             if (ihdr.org && ihdr.org != BTX_PGSIZE)
 216                 Warn(fname,
 217                      "Client origin is 0x%x; expecting 0 or 0x%x",
 218                      ihdr.org, BTX_PGSIZE);
 219         }
 220     }
 221     memset(&ohdr, 0, sizeof(ohdr));
 222     ohdr.fmt = format;
 223     ohdr.text = ldr_size;
 224     ohdr.data = btx.btx_textsz + ihdr.size;
 225     ohdr.org = lentry;
 226     ohdr.entry = lentry;
 227     cwr = 0;
 228     if (wpage > 0 || (wpage == -1 && !(ihdr.flags & IMPURE))) {
 229         if (wpage > 0)
 230             cwr = wpage;
 231         else {
 232             cwr = howmany(ihdr.text, BTX_PGSIZE);
 233             if (cwr > BTX_MAXCWR)
 234                 cwr = BTX_MAXCWR;
 235         }
 236     }
 237     if (ppage > 0 || (ppage && wpage && ihdr.org >= BTX_PGSIZE)) {
 238         btx.btx_flags |= BTX_MAPONE;
 239         if (!cwr)
 240             cwr++;
 241     }
 242     btx.btx_pgctl -= cwr;
 243     btx.btx_entry = Eflag ? centry : ihdr.entry;
 244     if ((size_t)snprintf(name, sizeof(name), "%s.tmp", oname) >= sizeof(name))
 245         errx(2, "%s: Filename too long", oname);
 246     if ((fdo = open(name, O_CREAT | O_TRUNC | O_WRONLY, 0666)) == -1)
 247         err(2, "%s", name);
 248     if (!(tname = strdup(name)))
 249         err(2, NULL);
 250     puthdr(fdo, &ohdr);
 251     for (i = I_LDR; i <= I_CLNT; i++) {
 252         fname = i == I_LDR ? lname : i == I_BTX ? bname : iname;
 253         switch (i) {
 254         case I_LDR:
 255             copy(fdi[i], fdo, ldr_size, 0);
 256             seekx(fdo, ohdr.size += ohdr.text);
 257             break;
 258         case I_BTX:
 259             writex(fdo, &btx, sizeof(btx));
 260             copy(fdi[i], fdo, btx.btx_textsz - sizeof(btx),
 261                  sizeof(btx));
 262             break;
 263         case I_CLNT:
 264             copy(fdi[i], fdo, ihdr.size, 0);
 265             if (ftruncate(fdo, ohdr.size += ohdr.data))
 266                 err(2, "%s", tname);
 267         }
 268         if (close(fdi[i]))
 269             err(2, "%s", fname);
 270     }
 271     if (close(fdo))
 272         err(2, "%s", tname);
 273     if (rename(tname, oname))
 274         err(2, "%s: Can't rename to %s", tname, oname);
 275     tname = NULL;
 276     if (verbose) {
 277         printf(binfo, btx.btx_majver, btx.btx_minver, btx.btx_textsz,
 278                BTX_ORIGIN(btx), BTX_ENTRY(btx), BTX_MAPPED(btx) *
 279                BTX_PGSIZE / 0x100000, !!(btx.btx_flags & BTX_MAPONE),
 280                BTX_MAPPED(btx) - btx.btx_pgctl - BTX_PGBASE /
 281                BTX_PGSIZE - BTX_MAPPED(btx) * 4 / BTX_PGSIZE);
 282         printf(cinfo, fmtlist[ihdr.fmt], ihdr.size, ihdr.text,
 283                ihdr.data, ihdr.bss, ihdr.entry);
 284         printf(oinfo, fmtlist[ohdr.fmt], ohdr.size, ohdr.text,
 285                ohdr.data, ohdr.org, ohdr.entry);
 286     }
 287 }
 288
 289 /*
 290  * Read BTX file header.
 291  */
 292 static void
 293 getbtx(int fd, struct btx_hdr * btx)
 294 {
 295     if (readx(fd, btx, sizeof(*btx), 0) != sizeof(*btx) ||
 296         btx->btx_magic[0] != BTX_MAG0 ||
 297         btx->btx_magic[1] != BTX_MAG1 ||
 298         btx->btx_magic[2] != BTX_MAG2)
 299         errx(1, "%s: Not a BTX kernel", fname);
 300 }
 301
 302 /*
 303  * Get file size and read a.out or ELF header.
 304  */
 305 static void
 306 gethdr(int fd, struct hdr *hdr)
 307 {
 308     struct stat sb;
 309     const struct exec *ex;
 310     const Elf32_Ehdr *ee;
 311     const Elf32_Phdr *ep;
 312     void *p;
 313     unsigned int fmt, x, n, i;
 314
 315     memset(hdr, 0, sizeof(*hdr));
 316     if (fstat(fd, &sb))
 317         err(2, "%s", fname);
 318     if (sb.st_size > MAXU32)
 319         errx(1, "%s: Too big", fname);
 320     hdr->size = sb.st_size;
 321     if ((p = mmap(NULL, hdr->size, PROT_READ, MAP_SHARED, fd,
 322                   0)) == MAP_FAILED)
 323         err(2, "%s", fname);
 324     for (fmt = F_CNT - 1; !hdr->fmt && fmt; fmt--)
 325         switch (fmt) {
 326         case F_AOUT:
 327             ex = p;
 328             if (hdr->size >= sizeof(struct exec) && !N_BADMAG(*ex)) {
 329                 hdr->fmt = fmt;
 330                 x = N_GETMAGIC(*ex);
 331                 if (x == OMAGIC || x == NMAGIC) {
 332                     if (x == NMAGIC)
 333                         Warn(fname, "Treating %s NMAGIC as OMAGIC",
 334                              fmtlist[fmt]);
 335                     hdr->flags |= IMPURE;
 336                 }
 337                 hdr->text = ex->a_text;
 338                 hdr->data = ex->a_data;
 339                 hdr->bss = ex->a_bss;
 340                 hdr->entry = ex->a_entry;
 341                 if (ex->a_entry >= BTX_PGSIZE)
 342                     hdr->org = BTX_PGSIZE;
 343             }
 344             break;
 345         case F_ELF:
 346             ee = p;
 347             if (hdr->size >= sizeof(Elf32_Ehdr) && IS_ELF(*ee)) {
 348                 hdr->fmt = fmt;
 349                 for (n = i = 0; i < ee->e_phnum; i++) {
 350                     ep = (void *)((uint8_t *)p + ee->e_phoff +
 351                                   ee->e_phentsize * i);
 352                     if (ep->p_type == PT_LOAD)
 353                         switch (n++) {
 354                         case 0:
 355                             hdr->text = ep->p_filesz;
 356                             hdr->org = ep->p_paddr;
 357                             if (ep->p_flags & PF_W)
 358                                 hdr->flags |= IMPURE;
 359                             break;
 360                         case 1:
 361                             hdr->data = ep->p_filesz;
 362                             hdr->bss = ep->p_memsz - ep->p_filesz;
 363                             break;
 364                         case 2:
 365                             Warn(fname,
 366                                  "Ignoring extra %s PT_LOAD segments",
 367                                  fmtlist[fmt]);
 368                         }
 369                 }
 370                 hdr->entry = ee->e_entry;
 371             }
 372         }
 373     if (munmap(p, hdr->size))
 374         err(2, "%s", fname);
 375 }
 376
 377 /*
 378  * Write a.out or ELF header.
 379  */
 380 static void
 381 puthdr(int fd, struct hdr *hdr)
 382 {
 383     struct exec ex;
 384     struct elfh eh;
 385
 386     switch (hdr->fmt) {
 387     case F_AOUT:
 388         memset(&ex, 0, sizeof(ex));
 389         N_SETMAGIC(ex, ZMAGIC, MID_ZERO, 0);
 390         hdr->text = N_ALIGN(ex, hdr->text);
 391         ex.a_text = hdr->text;
 392         hdr->data = N_ALIGN(ex, hdr->data);
 393         ex.a_data = hdr->data;
 394         ex.a_entry = hdr->entry;
 395         writex(fd, &ex, sizeof(ex));
 396         hdr->size = N_ALIGN(ex, sizeof(ex));
 397         seekx(fd, hdr->size);
 398         break;
 399     case F_ELF:
 400         eh = elfhdr;
 401         eh.e.e_entry = hdr->entry;
 402         eh.p[0].p_vaddr = eh.p[0].p_paddr = hdr->org;
 403         eh.p[0].p_filesz = eh.p[0].p_memsz = hdr->text;
 404         eh.p[1].p_offset = eh.p[0].p_offset + eh.p[0].p_filesz;
 405         eh.p[1].p_vaddr = eh.p[1].p_paddr =
 406             roundup2(eh.p[0].p_paddr + eh.p[0].p_memsz, 4);
 407         eh.p[1].p_filesz = eh.p[1].p_memsz = hdr->data;
 408         eh.sh[2].sh_addr = eh.p[0].p_vaddr;
 409         eh.sh[2].sh_offset = eh.p[0].p_offset;
 410         eh.sh[2].sh_size = eh.p[0].p_filesz;
 411         eh.sh[3].sh_addr = eh.p[1].p_vaddr;
 412         eh.sh[3].sh_offset = eh.p[1].p_offset;
 413         eh.sh[3].sh_size = eh.p[1].p_filesz;
 414         writex(fd, &eh, sizeof(eh));
 415         hdr->size = sizeof(eh);
 416     }
 417 }
 418
 419 /*
 420  * Safe copy from input file to output file.
 421  */
 422 static void
 423 copy(int fdi, int fdo, size_t nbyte, off_t offset)
 424 {
 425     char buf[8192];
 426     size_t n;
 427
 428     while (nbyte) {
 429         if ((n = sizeof(buf)) > nbyte)
 430             n = nbyte;
 431         if (readx(fdi, buf, n, offset) != n)
 432             errx(2, "%s: Short read", fname);
 433         writex(fdo, buf, n);
 434         nbyte -= n;
 435         offset = -1;
 436     }
 437 }
 438
 439 /*
 440  * Safe read from input file.
 441  */
 442 static size_t
 443 readx(int fd, void *buf, size_t nbyte, off_t offset)
 444 {
 445     ssize_t n;
 446
 447     if (offset != -1 && lseek(fd, offset, SEEK_SET) != offset)
 448         err(2, "%s", fname);
 449     if ((n = read(fd, buf, nbyte)) == -1)
 450         err(2, "%s", fname);
 451     return n;
 452 }
 453
 454 /*
 455  * Safe write to output file.
 456  */
 457 static void
 458 writex(int fd, const void *buf, size_t nbyte)
 459 {
 460     ssize_t n;
 461
 462     if ((n = write(fd, buf, nbyte)) == -1)
 463         err(2, "%s", tname);
 464     if ((size_t)n != nbyte)
 465         errx(2, "%s: Short write", tname);
 466 }
 467
 468 /*
 469  * Safe seek in output file.
 470  */
 471 static void
 472 seekx(int fd, off_t offset)
 473 {
 474     if (lseek(fd, offset, SEEK_SET) != offset)
 475         err(2, "%s", tname);
 476 }
 477
 478 /*
 479  * Convert an option argument to a format code.
 480  */
 481 static unsigned int
 482 optfmt(const char *arg)
 483 {
 484     unsigned int i;
 485
 486     for (i = 0; i < F_CNT && strcmp(arg, fmtlist[i]); i++);
 487     if (i == F_CNT)
 488         errx(1, "%s: Unknown format", arg);
 489     return i;
 490 }
 491
 492 /*
 493  * Convert an option argument to an address.
 494  */
 495 static uint32_t
 496 optaddr(const char *arg)
 497 {
 498     char *s;
 499     unsigned long x;
 500
 501     errno = 0;
 502     x = strtoul(arg, &s, 0);
 503     if (errno || !*arg || *s || x > MAXU32)
 504         errx(1, "%s: Illegal address", arg);
 505     return x;
 506 }
 507
 508 /*
 509  * Convert an option argument to a page number.
 510  */
 511 static int
 512 optpage(const char *arg, int hi)
 513 {
 514     char *s;
 515     long x;
 516
 517     errno = 0;
 518     x = strtol(arg, &s, 0);
 519     if (errno || !*arg || *s || x < 0 || x > hi)
 520         errx(1, "%s: Illegal page number", arg);
 521     return x;
 522 }
 523
 524 /*
 525  * Display a warning.
 526  */
 527 static void
 528 Warn(const char *locus, const char *fmt, ...)
 529 {
 530     va_list ap;
 531     char *s;
 532
 533     if (!quiet) {
 534         asprintf(&s, "%s: Warning: %s", locus, fmt);
 535         va_start(ap, fmt);
 536         vwarnx(s, ap);
 537         va_end(ap);
 538         free(s);
 539     }
 540 }
 541
 542 /*
 543  * Display usage information.
 544  */
 545 static void
 546 usage(void)
 547 {
 548     fprintf(stderr, "%s\n%s\n",
 549     "usage: btxld [-qv] [-b file] [-E address] [-e address] [-f format]",
 550     "             [-l file] [-o filename] [-P page] [-W page] file");
 551     exit(1);
 552 }