src/ecrt0.c

   1 /* C code startup routine.
   2    Copyright (C) 1985, 1986, 1992, 2001, 2002, 2003, 2004,
   3                  2005, 2006, 2007 Free Software Foundation, Inc.
   4
   5 This file is part of GNU Emacs.
   6
   7 GNU Emacs is free software; you can redistribute it and/or modify
   8 it under the terms of the GNU General Public License as published by
   9 the Free Software Foundation; either version 3, or (at your option)
  10 any later version.
  11
  12 GNU Emacs is distributed in the hope that it will be useful,
  13 but WITHOUT ANY WARRANTY; without even the implied warranty of
  14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15 GNU General Public License for more details.
  16
  17 You should have received a copy of the GNU General Public License
  18 along with GNU Emacs; see the file COPYING.  If not, write to
  19 the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
  20 Boston, MA 02110-1301, USA.  */
  21
  22
  23 /* The standard Vax 4.2 Unix crt0.c cannot be used for Emacs
  24    because it makes `environ' an initialized variable.
  25    It is easiest to have a special crt0.c on all machines
  26    though I don't know whether other machines actually need it.  */
  27
  28 /* On the vax and 68000, in BSD4.2 and USG5.2,
  29    this is the data format on startup:
  30   (vax) ap and fp are unpredictable as far as I know; don't use them.
  31   sp ->  word containing argc
  32          word pointing to first arg string
  33          [word pointing to next arg string]... 0 or more times
  34          0
  35 Optionally:
  36          [word pointing to environment variable]... 1 or more times
  37          ...
  38          0
  39 And always:
  40          first arg string
  41          [next arg string]... 0 or more times
  42 */
  43
  44 /* On the 16000, at least in the one 4.2 system I know about,
  45   the initial data format is
  46   sp ->  word containing argc
  47          word containing argp
  48          word pointing to first arg string, and so on as above
  49 */
  50
  51 #ifdef emacs
  52 #include <config.h>
  53 #endif
  54
  55 /*              ********  WARNING ********
  56     Do not insert any data definitions before data_start!
  57     Since this is the first file linked, the address of the following
  58     variable should correspond to the start of initialized data space.
  59     On some systems this is a constant that is independent of the text
  60     size for shared executables.  On others, it is a function of the
  61     text size. In short, this seems to be the most portable way to
  62     discover the start of initialized data space dynamically at runtime,
  63     for either shared or unshared executables, on either swapping or
  64     virtual systems.  It only requires that the linker allocate objects
  65     in the order encountered, a reasonable model for most Unix systems.
  66     Similarly, note that the address of _start() should be the start
  67     of text space.   Fred Fish, UniSoft Systems Inc.  */
  68
  69 int data_start = 0;
  70
  71 #ifdef NEED_ERRNO
  72 int errno;
  73 #endif
  74
  75 #ifndef DONT_NEED_ENVIRON
  76 char **environ;
  77 #endif
  78
  79 #ifndef static
  80 /* On systems where the static storage class is usable, this function
  81    should be declared as static.  Otherwise, the static keyword has
  82    been defined to be something else, and code for those systems must
  83    take care of this declaration appropriately.  */
  84 static start1 ();
  85 #endif
  86
  87 #ifdef APOLLO
  88 extern  char   *malloc(), *realloc(), *(*_libc_malloc) (), *(*_libc_realloc)();
  89 extern  void    free(), (*_libc_free) (); extern int main();
  90 std_$call void  unix_$main();
  91
  92 _start()
  93 {
  94         _libc_malloc = malloc;
  95         _libc_realloc = realloc;
  96         _libc_free = free;
  97         unix_$main(main);       /* no return */
  98 }
  99 #endif /* APOLLO */
 100
 101 #if defined(orion) || defined(pyramid) || defined(celerity) || defined(ALLIANT) || defined(clipper) || defined(sps7)
 102
 103 #if defined(sps7) && defined(V3x)
 104         asm("   section 10");
 105         asm("   ds.b    0xb0");
 106 #endif
 107
 108 #ifdef ALLIANT
 109 /* _start must initialize _curbrk and _minbrk on the first startup;
 110    when starting up after dumping, it must initialize them to what they were
 111    before the dumping, since they are in the shared library and
 112    are not dumped.  See ADJUST_EXEC_HEADER in m-alliant.h.  */
 113 extern unsigned char *_curbrk, *_minbrk;
 114 extern unsigned char end;
 115 unsigned char *_setbrk = &end;
 116 #ifdef ALLIANT_2800
 117 unsigned char *_end = &end;
 118 #endif
 119 #endif
 120
 121 #ifndef DUMMIES
 122 #define DUMMIES
 123 #endif
 124
 125 _start (DUMMIES argc, argv, envp)
 126      int argc;
 127      char **argv, **envp;
 128 {
 129 #ifdef ALLIANT
 130 #ifdef ALLIANT_2800
 131   _curbrk = _end;
 132   _minbrk = _end;
 133 #else
 134   _curbrk = _setbrk;
 135   _minbrk = _setbrk;
 136 #endif
 137 #endif
 138
 139   environ = envp;
 140
 141   exit (main (argc, argv, envp));
 142 }
 143
 144 #endif /* orion or pyramid or celerity or alliant or clipper */
 145
 146 #if defined (ns16000) && !defined (sequent) && !defined (UMAX) && !defined (CRT0_DUMMIES)
 147
 148 _start ()
 149 {
 150 /* On 16000, _start pushes fp onto stack */
 151   start1 ();
 152 }
 153
 154 /* ignore takes care of skipping the fp value pushed in start.  */
 155 static
 156 start1 (ignore, argc, argv)
 157      int ignore;
 158      int argc;
 159      register char **argv;
 160 {
 161   environ = argv + argc + 1;
 162
 163   if (environ == *argv)
 164     environ--;
 165   exit (main (argc, argv, environ));
 166 }
 167 #endif /* ns16000, not sequent and not UMAX, and not the CRT0_DUMMIES method */
 168
 169 #ifdef UMAX
 170 _start()
 171 {
 172         asm("   exit []                 # undo enter");
 173         asm("   .set    exitsc,1");
 174         asm("   .set    sigcatchall,0x400");
 175
 176         asm("   .globl  _exit");
 177         asm("   .globl  start");
 178         asm("   .globl  __start");
 179         asm("   .globl  _main");
 180         asm("   .globl  _environ");
 181         asm("   .globl  _sigvec");
 182         asm("   .globl  sigentry");
 183
 184         asm("start:");
 185         asm("   br      .xstart");
 186         asm("   .org    0x20");
 187         asm("   .double p_glbl,0,0xf00000,0");
 188         asm("   .org    0x30");
 189         asm(".xstart:");
 190         asm("   adjspb  $8");
 191         asm("   movd    8(sp),0(sp)     # argc");
 192         asm("   addr    12(sp),r0");
 193         asm("   movd    r0,4(sp)        # argv");
 194         asm("L1:");
 195         asm("   movd    r0,r1");
 196         asm("   addqd   $4,r0");
 197         asm("   cmpqd   $0,0(r1)        # null args term ?");
 198         asm("   bne     L1");
 199         asm("   cmpd    r0,0(4(sp))     # end of 'env' or 'argv' ?");
 200         asm("   blt     L2");
 201         asm("   addqd   $-4,r0          # envp's are in list");
 202         asm("L2:");
 203         asm("   movd    r0,8(sp)        # env");
 204         asm("   movd    r0,@_environ    # indir is 0 if no env ; not 0 if env");
 205         asm("   movqd   $0,tos          # setup intermediate signal handler");
 206         asm("   addr    @sv,tos");
 207         asm("   movzwd  $sigcatchall,tos");
 208         asm("   jsr     @_sigvec");
 209         asm("   adjspb  $-12");
 210         asm("   jsr     @_main");
 211         asm("   adjspb  $-12");
 212         asm("   movd    r0,tos");
 213         asm("   jsr     @_exit");
 214         asm("   adjspb  $-4");
 215         asm("   addr    @exitsc,r0");
 216         asm("   svc");
 217         asm("   .align  4               # sigvec arg");
 218         asm("sv:");
 219         asm("   .double sigentry");
 220         asm("   .double 0");
 221         asm("   .double 0");
 222
 223         asm("   .comm   p_glbl,1");
 224 }
 225 #endif /* UMAX */
 226
 227 #ifdef CRT0_DUMMIES
 228
 229 /* Define symbol "start": here; some systems want that symbol.  */
 230 #ifdef DOT_GLOBAL_START
 231 asm("   .text           ");
 232 asm("   .globl start    ");
 233 asm("   start:          ");
 234 #endif /* DOT_GLOBAL_START */
 235
 236 #ifdef NODOT_GLOBAL_START
 237 asm("   text            ");
 238 asm("   global start    ");
 239 asm("   start:          ");
 240 #endif /* NODOT_GLOBAL_START */
 241
 242 #ifdef m68000
 243
 244 /* GCC 2.1, when optimization is turned off, seems to want to push a
 245    word of garbage on the stack, which screws up the CRT0_DUMMIES
 246    hack.  So we hand-code _start in assembly language.  */
 247 asm(".text                      ");
 248 asm("   .even                   ");
 249 asm(".globl __start             ");
 250 asm("__start:                   ");
 251 asm("   link a6,#0              ");
 252 asm("   jbsr _start1            ");
 253 asm("   unlk a6                 ");
 254 asm("   rts                     ");
 255
 256 #else /* not m68000 */
 257
 258 _start ()
 259 {
 260 /* On vax, nothing is pushed here  */
 261 /* On sequent, bogus fp is pushed here  */
 262   start1 ();
 263 }
 264
 265 #endif /* possibly m68000 */
 266
 267 static
 268 start1 (CRT0_DUMMIES argc, xargv)
 269      int argc;
 270      char *xargv;
 271 {
 272   register char **argv = &xargv;
 273   environ = argv + argc + 1;
 274
 275   if ((char *)environ == xargv)
 276     environ--;
 277   exit (main (argc, argv, environ));
 278
 279   /* Refer to `start1' so GCC will not think it is never called
 280      and optimize it out.  */
 281   (void) &start1;
 282 }
 283 #else /* not CRT0_DUMMIES */
 284
 285 /* "m68k" and "m68000" both stand for m68000 processors,
 286    but with different program-entry conventions.
 287    This is a kludge.  Now that the CRT0_DUMMIES mechanism above exists,
 288    most of these machines could use the vax code above
 289    with some suitable definition of CRT0_DUMMIES.
 290    Then the symbol m68k could be flushed.
 291    But I don't want to risk breaking these machines
 292    in a version 17 patch release, so that change is being put off.  */
 293
 294 #ifdef m68k                     /* Can't do it all from C */
 295         asm ("  global  _start");
 296         asm ("  text");
 297         asm ("_start:");
 298 #ifndef NU
 299 #ifdef STRIDE
 300         asm ("  comm    havefpu%,2");
 301 #else /* m68k, not STRIDE */
 302         asm ("  comm    splimit%,4");
 303 #endif /* STRIDE */
 304         asm ("  global  exit");
 305         asm ("  text");
 306 #ifdef STRIDE
 307         asm ("  trap    &3");
 308         asm ("  mov.w   %d0,havefpu%");
 309 #else /* m68k, not STRIDE */
 310         asm ("  mov.l   %d0,splimit%");
 311 #endif /* STRIDE */
 312 #endif /* not NU */
 313         asm ("  jsr     start1");
 314         asm ("  mov.l   %d0,(%sp)");
 315         asm ("  jsr     exit");
 316         asm ("  mov.l   &1,%d0");       /* d0 = 1 => exit */
 317         asm ("  trap    &0");
 318 #else /* m68000, not m68k */
 319
 320 #ifdef m68000
 321
 322 #ifdef ISI68K
 323 /* Added by ESM Sun May 24 12:44:02 1987 to get new ISI library to work */
 324 /* Edited by Ray Mon May 15 15:59:56 EST 1989 so we can compile with gcc */
 325 #if defined(BSD4_3) && !defined(__GNUC__)
 326 static foo () {
 327 #endif
 328         asm ("  .globl  is68020");
 329         asm ("is68020:");
 330 #ifndef BSD4_3
 331         asm ("  .long   0x00000000");
 332         asm ("  .long   0xffffffff");
 333 /* End of stuff added by ESM */
 334 #endif
 335         asm ("  .text");
 336         asm ("  .globl  __start");
 337         asm ("__start:");
 338         asm ("  .word 0");
 339         asm ("  link    a6,#0");
 340         asm ("  jbsr    _start1");
 341         asm ("  unlk    a6");
 342         asm ("  rts");
 343 #if defined(BSD4_3) && !defined(__GNUC__)
 344       }
 345 #endif
 346 #else /* not ISI68K */
 347
 348 _start ()
 349 {
 350 #ifdef sun
 351   finitfp_();
 352 #endif
 353 /* On 68000, _start pushes a6 onto stack  */
 354   start1 ();
 355 }
 356 #endif /* not ISI68k */
 357 #endif /* m68000 */
 358 #endif /* m68k */
 359
 360 #if defined(m68k) || defined(m68000)
 361 /* ignore takes care of skipping the a6 value pushed in start.  */
 362 static
 363 #if defined(m68k)
 364 start1 (argc, xargv)
 365 #else
 366 start1 (ignore, argc, xargv)
 367 #endif
 368      int argc;
 369      char *xargv;
 370 {
 371   register char **argv = &xargv;
 372   environ = argv + argc + 1;
 373
 374   if ((char *)environ == xargv)
 375     environ--;
 376 #ifdef sun_68881
 377   asm("    jsr     f68881_used");
 378 #endif
 379 #ifdef sun_fpa
 380   asm("    jsr     ffpa_used");
 381 #endif
 382 #ifdef sun_soft
 383   asm("    jsr     start_float");
 384 #endif
 385   exit (main (argc, argv, environ));
 386 }
 387
 388 #endif /* m68k or m68000 */
 389
 390 #endif /* not CRT0_DUMMIES */
 391
 392 #ifdef hp9000s300
 393 int argc_value;
 394 char **argv_value;
 395 #ifdef OLD_HP_ASSEMBLER
 396         asm("   text");
 397         asm("   globl __start");
 398         asm("   globl _exit");
 399         asm("   globl _main");
 400         asm("__start");
 401         asm("   dc.l    0");
 402         asm("   subq.w  #0x1,d0");
 403         asm("   move.w  d0,float_soft");
 404         asm("   move.l  0x4(a7),d0");
 405         asm("   beq.s   skip_1");
 406         asm("   move.l  d0,a0");
 407         asm("   clr.l   -0x4(a0)");
 408         asm("skip_1");
 409         asm("   move.l  a7,a0");
 410         asm("   subq.l  #0x8,a7");
 411         asm("   move.l  (a0),(a7)");
 412         asm("   move.l  (a0),_argc_value");
 413         asm("   addq.l  #0x4,a0");
 414         asm("   move.l  a0,0x4(a7)");
 415         asm("   move.l  a0,_argv_value");
 416         asm("incr_loop");
 417         asm("   tst.l   (a0)+");
 418         asm("   bne.s   incr_loop");
 419         asm("   move.l  0x4(a7),a1");
 420         asm("   cmp.l   (a1),a0");
 421         asm("   blt.s   skip_2");
 422         asm("   subq.l  #0x4,a0");
 423         asm("skip_2");
 424         asm("   move.l  a0,0x8(a7)");
 425         asm("   move.l  a0,_environ");
 426         asm("   jsr     _main");
 427         asm("   addq.l  #0x8,a7");
 428         asm("   move.l  d0,-(a7)");
 429         asm("   jsr     _exit");
 430         asm("   move.w  #0x1,d0");
 431         asm("   trap    #0x0");
 432         asm("   comm    float_soft,4");
 433 /* float_soft is allocated in this way because C would
 434    put an underscore character in its name otherwise. */
 435
 436 #else /* new hp assembler */
 437
 438         asm("   text");
 439         asm("   global  float_loc");
 440         asm("   set     float_loc,0xFFFFB000");
 441         asm("   global  fpa_loc");
 442         asm("   set     fpa_loc,0xfff08000");
 443         asm("   global  __start");
 444         asm("   global  _exit");
 445         asm("   global  _main");
 446         asm("__start:");
 447         asm("   byte    0,0,0,0");
 448         asm("   subq.w  &1,%d0");
 449         asm("   mov.w   %d0,float_soft");
 450         asm("   mov.w   %d1,flag_68881");
 451 #ifndef HPUX_68010
 452         asm("   beq.b   skip_float");
 453         asm("   fmov.l  &0x7400,%fpcr");
 454 /*      asm("   fmov.l  &0x7480,%fpcr"); */
 455 #endif /* HPUX_68010 */
 456         asm("skip_float:");
 457         asm("   mov.l   %a0,%d0");
 458         asm("   add.l   %d0,%d0");
 459         asm("   subx.w  %d1,%d1");
 460         asm("   mov.w   %d1,flag_68010");
 461         asm("   add.l   %d0,%d0");
 462         asm("   subx.w  %d1,%d1");
 463         asm("   mov.w   %d1,flag_fpa");
 464         asm("   tst.l   %d2");
 465         asm("   ble.b   skip_3");
 466         asm("   lsl     flag_68881");
 467         asm("   lsl     flag_fpa");
 468         asm("skip_3:");
 469         asm("   mov.l   4(%a7),%d0");
 470         asm("   beq.b   skip_1");
 471         asm("   mov.l   %d0,%a0");
 472         asm("   clr.l   -4(%a0)");
 473         asm("skip_1:");
 474         asm("   mov.l   %a7,%a0");
 475         asm("   subq.l  &8,%a7");
 476         asm("   mov.l   (%a0),(%a7)");
 477         asm("   mov.l   (%a0),_argc_value");
 478         asm("   addq.l  &4,%a0");
 479         asm("   mov.l   %a0,4(%a7)");
 480         asm("   mov.l   %a0,_argv_value");
 481         asm("incr_loop:");
 482         asm("   tst.l   (%a0)+");
 483         asm("   bne.b   incr_loop");
 484         asm("   mov.l   4(%a7),%a1");
 485         asm("   cmp.l   %a0,(%a1)");
 486         asm("   blt.b   skip_2");
 487         asm("   subq.l  &4,%a0");
 488         asm("skip_2:");
 489         asm("   mov.l   %a0,8(%a7)");
 490         asm("   mov.l   %a0,_environ");
 491         asm("   jsr     _main");
 492         asm("   addq.l  &8,%a7");
 493         asm("   mov.l   %d0,-(%a7)");
 494         asm("   jsr     _exit");
 495         asm("   mov.w   &1,%d0");
 496         asm("   trap    &0");
 497         asm("   comm    float_soft, 4");
 498         asm("   comm    flag_68881, 4");
 499         asm("   comm    flag_68010, 4");
 500         asm("   comm    flag_68040, 4");
 501         asm("   comm    flag_fpa, 4");
 502
 503 #endif /* new hp assembler */
 504 #endif /* hp9000s300 */
 505
 506 #ifdef GOULD
 507
 508 /* startup code has to be in near text rather
 509    than fartext as allocated by the C compiler. */
 510         asm("   .text");
 511         asm("   .align  2");
 512         asm("   .globl  __start");
 513         asm("   .text");
 514         asm("__start:");
 515 /* setup base register b1 (function base). */
 516         asm("   .using  b1,.");
 517         asm("   tpcbr   b1");
 518 /* setup base registers b3 through b7 (data references). */
 519         asm("   file    basevals,b3");
 520 /* setup base register b2 (stack pointer); it should be
 521    aligned on a 8-word boundary; but because it is pointing
 522    to argc, its value should be remembered (in r5). */
 523         asm("   movw    b2,r4");
 524         asm("   movw    b2,r5");
 525         asm("   andw    #~0x1f,r4");
 526         asm("   movw    r4,b2");
 527 /* allocate stack frame to do some work. */
 528         asm("   subea   16w,b2");
 529 /* initialize signal catching for UTX/32 1.2; this is
 530    necessary to make restart from saved image work. */
 531         asm("   movea   sigcatch,r1");
 532         asm("   movw    r1,8w[b2]");
 533         asm("   svc     #1,#150");
 534 /* setup address of argc for start1. */
 535         asm("   movw    r5,8w[b2]");
 536         asm("   func    #1,_start1");
 537         asm("   halt");
 538 /* space for ld to store base register initial values. */
 539         asm("   .align  5");
 540         asm("basevals:");
 541         asm("   .word   __base3,__base4,__base5,__base6,__base7");
 542
 543 static
 544 start1 (xargc)
 545      int *xargc;
 546 {
 547   register int  argc;
 548   register char **argv;
 549
 550   argc = *xargc;
 551   argv = (char **)(xargc) + 1;
 552   environ = argv + argc + 1;
 553
 554   if (environ == argv)
 555     environ--;
 556   exit (main (argc, argv, environ));
 557
 558 }
 559
 560 #endif /* GOULD */
 561
 562 #ifdef elxsi
 563 #include <elxsi/argvcache.h>
 564
 565 extern char **environ;
 566 extern int      errno;
 567 extern void     _init_doscan(), _init_iob();
 568 extern char     end[];
 569 char            *_init_brk = end;
 570
 571 _start()
 572 {
 573   environ = exec_cache.ac_envp;
 574   brk (_init_brk);
 575   errno = 0;
 576   _init_doscan ();
 577   _init_iob ();
 578   _exit (exit (main (exec_cache.ac_argc,
 579                      exec_cache.ac_argv,
 580                      exec_cache.ac_envp)));
 581 }
 582 #endif /* elxsi */
 583
 584
 585 #ifdef sparc
 586 asm (".global __start");
 587 asm (".text");
 588 asm ("__start:");
 589 asm ("  mov     0, %fp");
 590 asm ("  ld      [%sp + 64], %o0");
 591 asm ("  add     %sp, 68, %o1");
 592 asm ("  sll     %o0, 2, %o2");
 593 asm ("  add     %o2, 4, %o2");
 594 asm ("  add     %o1, %o2, %o2");
 595 asm ("  sethi   %hi(_environ), %o3");
 596 asm ("  st      %o2, [%o3+%lo(_environ)]");
 597 asm ("  andn    %sp, 7, %sp");
 598 asm ("  call    _main");
 599 asm ("  sub     %sp, 24, %sp");
 600 asm ("  call    __exit");
 601 asm ("  nop");
 602
 603 #endif /* sparc */
 604
 605 #if __FreeBSD__ == 2
 606 char *__progname;
 607 #endif
 608 #ifdef __bsdi__
 609 #include <sys/param.h> /* for version number */
 610 #if defined(_BSDI_VERSION) && (_BSDI_VERSION >= 199501)
 611 char *__progname;
 612 #endif
 613 #endif /* __bsdi__ */
 614
 615 /* arch-tag: 4025c2fb-d6b1-4d29-b1b6-8100b6bd1e74
 616    (do not change this comment) */