| 1 | /* |
| 2 | * Copyright (c) 1993 Paul Kranenburg |
| 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 | * 3. All advertising materials mentioning features or use of this software |
| 14 | * must display the following acknowledgement: |
| 15 | * This product includes software developed by Paul Kranenburg. |
| 16 | * 4. The name of the author may not be used to endorse or promote products |
| 17 | * derived from this software withough specific prior written permission |
| 18 | * |
| 19 | * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR |
| 20 | * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES |
| 21 | * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. |
| 22 | * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, |
| 23 | * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT |
| 24 | * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, |
| 25 | * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY |
| 26 | * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT |
| 27 | * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF |
| 28 | * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
| 29 | * |
| 30 | * $Id: crt0.c,v 1.6 1993/11/09 04:26:11 paul Exp $ |
| 31 | */ |
| 32 | |
| 33 | |
| 34 | #if defined(LIBC_SCCS) && !defined(lint) |
| 35 | static char sccsid[] = "%W% (Erasmus) %G%"; |
| 36 | #endif /* LIBC_SCCS and not lint */ |
| 37 | |
| 38 | extern void exit(); |
| 39 | int _callmain(); |
| 40 | |
| 41 | #include <sys/param.h> |
| 42 | |
| 43 | #ifdef DYNAMIC |
| 44 | #include <sys/types.h> |
| 45 | #include <sys/syscall.h> |
| 46 | #include <a.out.h> |
| 47 | #ifndef N_GETMAGIC |
| 48 | #define N_GETMAGIC(x) ((x).a_magic) |
| 49 | #endif |
| 50 | #ifndef N_BSSADDR |
| 51 | #define N_BSSADDR(x) (N_DATADDR(x)+(x).a_data) |
| 52 | #endif |
| 53 | #include <sys/mman.h> |
| 54 | #ifdef sun |
| 55 | #define MAP_COPY MAP_PRIVATE |
| 56 | #define MAP_FILE 0 |
| 57 | #define MAP_ANON 0 |
| 58 | #endif |
| 59 | #include <link.h> |
| 60 | |
| 61 | extern struct link_dynamic _DYNAMIC; |
| 62 | static void __do_dynamic_link (); |
| 63 | static char *_getenv(); |
| 64 | static int _strncmp(); |
| 65 | |
| 66 | #ifdef sparc |
| 67 | static __call(); |
| 68 | #endif |
| 69 | |
| 70 | #ifdef sun |
| 71 | #define LDSO "/usr/lib/ld.so" |
| 72 | #endif |
| 73 | #ifdef BSD |
| 74 | #define LDSO "/usr/libexec/ld.so" |
| 75 | #endif |
| 76 | |
| 77 | #endif /* DYNAMIC */ |
| 78 | |
| 79 | static char *_strrchr(); |
| 80 | |
| 81 | char **environ; |
| 82 | |
| 83 | #ifdef BSD |
| 84 | extern unsigned char etext; |
| 85 | extern unsigned char eprol asm ("eprol"); |
| 86 | extern start() asm("start"); |
| 87 | extern mcount() asm ("mcount"); |
| 88 | |
| 89 | int errno; |
| 90 | static char empty[1]; |
| 91 | char *__progname = empty; |
| 92 | #endif |
| 93 | |
| 94 | /* |
| 95 | * We need these system calls, but can't use library stubs |
| 96 | */ |
| 97 | #define _exit(v) __syscall(SYS_exit, (v)) |
| 98 | #define open(name, f, m) __syscall(SYS_open, (name), (f), (m)) |
| 99 | #define close(fd) __syscall(SYS_close, (fd)) |
| 100 | #define read(fd, s, n) __syscall(SYS_read, (fd), (s), (n)) |
| 101 | #define write(fd, s, n) __syscall(SYS_write, (fd), (s), (n)) |
| 102 | #define dup(fd) __syscall(SYS_dup, (fd)) |
| 103 | #define dup2(fd, fdnew) __syscall(SYS_dup2, (fd), (fdnew)) |
| 104 | #ifdef sun |
| 105 | #define mmap(addr, len, prot, flags, fd, off) \ |
| 106 | __syscall(SYS_mmap, (addr), (len), (prot), _MAP_NEW|(flags), (fd), (off)) |
| 107 | #else |
| 108 | #define mmap(addr, len, prot, flags, fd, off) \ |
| 109 | __syscall(SYS_mmap, (addr), (len), (prot), (flags), (fd), (off)) |
| 110 | #endif |
| 111 | |
| 112 | #define _FATAL(str) \ |
| 113 | write(2, str, sizeof(str)), \ |
| 114 | _exit(1); |
| 115 | |
| 116 | |
| 117 | #ifdef sparc |
| 118 | asm (" .global start"); |
| 119 | asm (" .text"); |
| 120 | asm (" start:"); |
| 121 | |
| 122 | /* Set up `argc', `argv', and `envp' into local registers (from GNU Emacs). */ |
| 123 | asm (" mov 0, %fp"); |
| 124 | asm (" ld [%sp + 64], %l0"); /* argc */ |
| 125 | asm (" add %sp, 68, %l1"); /* argv */ |
| 126 | asm (" sll %l0, 2, %l2"); /**/ |
| 127 | asm (" add %l2, 4, %l2"); /* envp = argv + (argc << 2) + 4 */ |
| 128 | asm (" add %l1, %l2, %l2"); /**/ |
| 129 | asm (" sethi %hi(_environ), %l3"); |
| 130 | asm (" st %l2, [%l3+%lo(_environ)]"); /* *environ = l2 */ |
| 131 | |
| 132 | /* Finish diddling with stack. */ |
| 133 | asm (" andn %sp, 7, %sp"); |
| 134 | asm (" sub %sp, 24, %sp"); |
| 135 | |
| 136 | #ifdef DYNAMIC |
| 137 | /* Resolve symbols in dynamic libraries */ |
| 138 | asm (" call ___do_dynamic_link"); |
| 139 | asm (" nop"); |
| 140 | #endif |
| 141 | |
| 142 | /* From here, all symbols should have been resolved, so we can use libc */ |
| 143 | #ifdef MCRT0 |
| 144 | asm (" call ___do_mcrt"); |
| 145 | asm (" nop"); |
| 146 | #endif |
| 147 | |
| 148 | /* Stay Sun compatible (currently (SunOS 4.1.2) does nothing on sun4) */ |
| 149 | asm (" call start_float"); |
| 150 | asm (" nop"); |
| 151 | |
| 152 | /* Move `argc', `argv', and `envp' from locals to parameters for `main'. */ |
| 153 | asm (" mov %l0,%o0"); |
| 154 | asm (" mov %l1,%o1"); |
| 155 | asm ("__callmain:"); /* Defined for the benefit of debuggers */ |
| 156 | asm (" call _main"); |
| 157 | asm (" mov %l2,%o2"); |
| 158 | |
| 159 | asm (" call _exit"); |
| 160 | asm (" nop"); |
| 161 | |
| 162 | #ifdef MCRT0 |
| 163 | static void |
| 164 | __do_mcrt () |
| 165 | { |
| 166 | extern unsigned char eprol, etext; |
| 167 | extern void _mcleanup(); |
| 168 | |
| 169 | on_exit(_mcleanup, 0); |
| 170 | monstartup(&eprol, &etext); |
| 171 | return; |
| 172 | } |
| 173 | #endif |
| 174 | |
| 175 | #endif /* sparc */ |
| 176 | |
| 177 | |
| 178 | #ifdef i386 |
| 179 | start() |
| 180 | { |
| 181 | struct kframe { |
| 182 | int kargc; |
| 183 | char *kargv[1]; /* size depends on kargc */ |
| 184 | char kargstr[1]; /* size varies */ |
| 185 | char kenvstr[1]; /* size varies */ |
| 186 | }; |
| 187 | /* |
| 188 | * ALL REGISTER VARIABLES!!! |
| 189 | */ |
| 190 | register struct kframe *kfp; |
| 191 | register char **targv; |
| 192 | register char **argv; |
| 193 | extern void _mcleanup(); |
| 194 | #ifdef DYNAMIC |
| 195 | volatile caddr_t x; |
| 196 | #endif |
| 197 | |
| 198 | #ifdef lint |
| 199 | kfp = 0; |
| 200 | initcode = initcode = 0; |
| 201 | #else /* not lint */ |
| 202 | /* just above the saved frame pointer */ |
| 203 | asm ("lea 4(%%ebp), %0" : "=r" (kfp) ); |
| 204 | #endif /* not lint */ |
| 205 | for (argv = targv = &kfp->kargv[0]; *targv++; /* void */) |
| 206 | /* void */ ; |
| 207 | if (targv >= (char **)(*argv)) |
| 208 | --targv; |
| 209 | environ = targv; |
| 210 | |
| 211 | #ifdef DYNAMIC |
| 212 | /* ld(1) convention: if DYNAMIC = 0 then statically linked */ |
| 213 | #ifdef stupid_gcc |
| 214 | if (&_DYNAMIC) |
| 215 | __do_dynamic_link(); |
| 216 | #else |
| 217 | x = (caddr_t)&_DYNAMIC; |
| 218 | if (x) |
| 219 | __do_dynamic_link(); |
| 220 | #endif |
| 221 | #endif /* DYNAMIC */ |
| 222 | |
| 223 | asm("eprol:"); |
| 224 | |
| 225 | #ifdef MCRT0 |
| 226 | atexit(_mcleanup); |
| 227 | monstartup(&eprol, &etext); |
| 228 | #endif MCRT0 |
| 229 | #if 0 |
| 230 | errno = 0; |
| 231 | #endif |
| 232 | if (argv[0]) |
| 233 | if ((__progname = _strrchr(argv[0], '/')) == NULL) |
| 234 | __progname = argv[0]; |
| 235 | else |
| 236 | ++__progname; |
| 237 | asm ("__callmain:"); /* Defined for the benefit of debuggers */ |
| 238 | exit(main(kfp->kargc, argv, environ)); |
| 239 | } |
| 240 | #endif /* i386 */ |
| 241 | |
| 242 | #ifdef DYNAMIC |
| 243 | static void |
| 244 | __do_dynamic_link () |
| 245 | { |
| 246 | struct crt_ldso crt; |
| 247 | struct exec hdr; |
| 248 | char *ldso; |
| 249 | int dupzfd; |
| 250 | void (*entry)(); |
| 251 | |
| 252 | #ifdef DEBUG |
| 253 | /* Provision for alternate ld.so - security risk! */ |
| 254 | if (!(ldso = _getenv("LDSO"))) |
| 255 | #endif |
| 256 | ldso = LDSO; |
| 257 | |
| 258 | crt.crt_ldfd = open(ldso, 0, 0); |
| 259 | if (crt.crt_ldfd == -1) { |
| 260 | _FATAL("No ld.so\n"); |
| 261 | } |
| 262 | |
| 263 | /* Read LDSO exec header */ |
| 264 | if (read(crt.crt_ldfd, &hdr, sizeof hdr) < sizeof hdr) { |
| 265 | _FATAL("Failure reading ld.so\n"); |
| 266 | } |
| 267 | if ((N_GETMAGIC_NET(hdr) != ZMAGIC) && (N_GETMAGIC(hdr) != QMAGIC)) { |
| 268 | _FATAL("Bad magic: ld.so\n"); |
| 269 | } |
| 270 | |
| 271 | #ifdef sun |
| 272 | /* Get bucket of zeroes */ |
| 273 | crt.crt_dzfd = open("/dev/zero", 0, 0); |
| 274 | if (crt.crt_dzfd == -1) { |
| 275 | _FATAL("No /dev/zero\n"); |
| 276 | } |
| 277 | #endif |
| 278 | #ifdef BSD |
| 279 | /* We use MAP_ANON */ |
| 280 | crt.crt_dzfd = -1; |
| 281 | #endif |
| 282 | |
| 283 | #if defined(sun) && defined(DUPZFD) |
| 284 | if ((dupzfd = dup(crt.crt_dzfd)) < 0) { |
| 285 | _FATAL("Cannot dup /dev/zero\n"); |
| 286 | } |
| 287 | #endif |
| 288 | |
| 289 | /* Map in ld.so */ |
| 290 | crt.crt_ba = mmap(0, hdr.a_text, |
| 291 | PROT_READ|PROT_EXEC, |
| 292 | MAP_FILE|MAP_COPY, |
| 293 | crt.crt_ldfd, N_TXTOFF(hdr)); |
| 294 | if (crt.crt_ba == -1) { |
| 295 | _FATAL("Cannot map ld.so\n"); |
| 296 | } |
| 297 | |
| 298 | #ifdef BSD |
| 299 | /* !!! |
| 300 | * This is gross, ld.so is a ZMAGIC a.out, but has `sizeof(hdr)' for |
| 301 | * an entry point and not at PAGSIZ as the N_*ADDR macros assume. |
| 302 | */ |
| 303 | #undef N_DATADDR |
| 304 | #undef N_BSSADDR |
| 305 | #define N_DATADDR(x) ((x).a_text) |
| 306 | #define N_BSSADDR(x) ((x).a_text + (x).a_data) |
| 307 | #endif |
| 308 | |
| 309 | /* Map in data segment of ld.so writable */ |
| 310 | if (mmap(crt.crt_ba+N_DATADDR(hdr), hdr.a_data, |
| 311 | PROT_READ|PROT_WRITE, |
| 312 | MAP_FIXED|MAP_FILE|MAP_COPY, |
| 313 | crt.crt_ldfd, N_DATOFF(hdr)) == -1) { |
| 314 | _FATAL("Cannot map ld.so\n"); |
| 315 | } |
| 316 | |
| 317 | /* Map bss segment of ld.so zero */ |
| 318 | if (hdr.a_bss && mmap(crt.crt_ba+N_BSSADDR(hdr), hdr.a_bss, |
| 319 | PROT_READ|PROT_WRITE, |
| 320 | MAP_FIXED|MAP_ANON|MAP_COPY, |
| 321 | crt.crt_dzfd, 0) == -1) { |
| 322 | _FATAL("Cannot map ld.so\n"); |
| 323 | } |
| 324 | |
| 325 | crt.crt_dp = &_DYNAMIC; |
| 326 | crt.crt_ep = environ; |
| 327 | crt.crt_bp = (caddr_t)_callmain; |
| 328 | |
| 329 | #if defined(sparc) && defined(SUN_COMPAT) |
| 330 | /* Call Sun's ld.so entry point: version 1, offset crt */ |
| 331 | __call(CRT_VERSION_SUN, &crt, crt.crt_ba + sizeof hdr); |
| 332 | #else |
| 333 | entry = (void (*)())(crt.crt_ba + sizeof hdr); |
| 334 | #ifdef SUN_COMPAT |
| 335 | (*entry)(CRT_VERSION_SUN, &crt); |
| 336 | #else |
| 337 | (*entry)(CRT_VERSION_BSD, &crt); |
| 338 | #endif |
| 339 | #endif |
| 340 | |
| 341 | #if defined(sun) && defined(DUPZFD) |
| 342 | if (dup2(dupzfd, crt.crt_dzfd) < 0) { |
| 343 | _FATAL("Cannot dup2 /dev/zero\n"); |
| 344 | } |
| 345 | (void)close(dupzfd); |
| 346 | #endif |
| 347 | return; |
| 348 | } |
| 349 | |
| 350 | #ifdef sparc |
| 351 | static |
| 352 | __call() |
| 353 | { |
| 354 | /* |
| 355 | * adjust the C generated pointer to the crt struct to the |
| 356 | * likings of ld.so, which is an offset relative to its %fp |
| 357 | */ |
| 358 | #if 0 |
| 359 | asm("___call:"); |
| 360 | asm("call %o2"); |
| 361 | asm("sub %o1, %sp, %o1"); /* adjust parameter */ |
| 362 | #else Hmmm... |
| 363 | asm("mov %i0, %o0"); |
| 364 | asm("mov %i1, %o1"); |
| 365 | asm("call %i2"); |
| 366 | asm("sub %o1, %sp, %o1"); |
| 367 | /*NOTREACHED, control is transferred directly to our caller */ |
| 368 | #endif |
| 369 | } |
| 370 | #endif |
| 371 | |
| 372 | /* |
| 373 | * Support routines |
| 374 | */ |
| 375 | |
| 376 | static int |
| 377 | _strncmp(s1, s2, n) |
| 378 | register char *s1, *s2; |
| 379 | register n; |
| 380 | { |
| 381 | |
| 382 | if (n == 0) |
| 383 | return (0); |
| 384 | do { |
| 385 | if (*s1 != *s2++) |
| 386 | return (*(unsigned char *)s1 - *(unsigned char *)--s2); |
| 387 | if (*s1++ == 0) |
| 388 | break; |
| 389 | } while (--n != 0); |
| 390 | return (0); |
| 391 | } |
| 392 | |
| 393 | static char * |
| 394 | _getenv(name) |
| 395 | register char *name; |
| 396 | { |
| 397 | extern char **environ; |
| 398 | register int len; |
| 399 | register char **P, *C; |
| 400 | |
| 401 | for (C = name, len = 0; *C && *C != '='; ++C, ++len); |
| 402 | for (P = environ; *P; ++P) |
| 403 | if (!_strncmp(*P, name, len)) |
| 404 | if (*(C = *P + len) == '=') { |
| 405 | return(++C); |
| 406 | } |
| 407 | return (char *)0; |
| 408 | } |
| 409 | |
| 410 | #ifdef sparc |
| 411 | /* System call entry */ |
| 412 | asm("___syscall:"); |
| 413 | asm("clr %g1"); |
| 414 | asm("ta %g0"); |
| 415 | asm("bgeu Lsyscallx"); /* good result ? */ |
| 416 | asm("nop"); |
| 417 | asm("mov -0x1, %o0"); /* Note: no `errno' */ |
| 418 | asm("Lsyscallx:"); |
| 419 | asm("jmp %o7 + 0x8"); |
| 420 | asm("nop"); |
| 421 | #endif /* sparc */ |
| 422 | #ifdef i386 |
| 423 | asm(" ___syscall:"); |
| 424 | asm(" popl %ecx"); |
| 425 | asm(" popl %eax"); |
| 426 | asm(" pushl %ecx"); |
| 427 | asm(" .byte 0x9a"); |
| 428 | asm(" .long 0"); |
| 429 | asm(" .word 7"); |
| 430 | asm(" pushl %ecx"); |
| 431 | asm(" jc 1f"); |
| 432 | asm(" ret"); |
| 433 | asm(" 1:"); |
| 434 | asm(" movl $-1,%eax"); |
| 435 | asm(" ret"); |
| 436 | #endif /* i386 */ |
| 437 | |
| 438 | #endif /* DYNAMIC */ |
| 439 | |
| 440 | static char * |
| 441 | _strrchr(p, ch) |
| 442 | register char *p, ch; |
| 443 | { |
| 444 | register char *save; |
| 445 | |
| 446 | for (save = NULL;; ++p) { |
| 447 | if (*p == ch) |
| 448 | save = (char *)p; |
| 449 | if (!*p) |
| 450 | return(save); |
| 451 | } |
| 452 | /* NOTREACHED */ |
| 453 | } |
| 454 | |
| 455 | #ifdef MCRT0 |
| 456 | asm (" .text"); |
| 457 | asm ("_eprol:"); |
| 458 | #endif |