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Diffstat (limited to 'sysdeps/unix/sparc/start.c')
| -rw-r--r-- | sysdeps/unix/sparc/start.c | 184 |
1 files changed, 184 insertions, 0 deletions
diff --git a/sysdeps/unix/sparc/start.c b/sysdeps/unix/sparc/start.c new file mode 100644 index 0000000000..e0f39f5b73 --- /dev/null +++ b/sysdeps/unix/sparc/start.c @@ -0,0 +1,184 @@ +/* Copyright (C) 1991, 1992, 1993, 1994, 1995 Free Software Foundation, Inc. +This file is part of the GNU C Library. + +The GNU C Library is free software; you can redistribute it and/or +modify it under the terms of the GNU Library General Public License as +published by the Free Software Foundation; either version 2 of the +License, or (at your option) any later version. + +The GNU C Library is distributed in the hope that it will be useful, +but WITHOUT ANY WARRANTY; without even the implied warranty of +MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU +Library General Public License for more details. + +You should have received a copy of the GNU Library General Public +License along with the GNU C Library; see the file COPYING.LIB. If +not, write to the Free Software Foundation, Inc., 675 Mass Ave, +Cambridge, MA 02139, USA. */ + +#include <ansidecl.h> +#include <errno.h> +#include <stdlib.h> +#include <unistd.h> +#include <fcntl.h> + +#ifndef NO_SHLIB +#include <sys/exec.h> +#include <sys/types.h> +#include <sys/mman.h> +#include <link.h> +#include <syscall.h> +#endif + +#if !defined (__GNUC__) || __GNUC__ < 2 + #error This file uses GNU C extensions; you must compile with GCC version 2. +#endif + +/* The first piece of initialized data. */ +int __data_start = 0; +#ifdef HAVE_WEAK_SYMBOLS +weak_alias (__data_start, data_start) +#endif + +VOLATILE int errno; + +#ifdef HAVE_WEAK_SYMBOLS +weak_alias (__environ, environ) +#else +#undef environ +#define __environ environ +#endif + +char **__environ; + +extern void EXFUN(__libc_init, (int argc, char **argv, char **envp)); +extern int EXFUN(main, (int argc, char **argv, char **envp)); + +register long int sp asm("%sp"), fp asm("%fp"); + +#ifndef NO_SHLIB +static void EXFUN(init_shlib, (NOARGS)); +#endif + +#ifndef NO_EXPLICIT_START +/* Declare _start with an explicit assembly symbol name of `start' + (note no leading underscore). This is the name Sun's crt0.o uses, + and programs are often linked with `ld -e start'. */ +void _start (void) asm ("start"); +#endif + +void +_start (void) +{ + /* It is important that these be declared `register'. + Otherwise, when compiled without optimization, they are put on the + stack, which loses completely after we zero the FP. */ + register int argc; + register char **argv, **envp; + + /* Unwind the frame built when we entered the function. */ + asm("restore"); + + /* And clear the frame pointer. */ + fp = 0; + + /* The argument info starts after one register + window (64 bytes) past the SP. */ + argc = ((int *) sp)[16]; + argv = (char **) &((int *) sp)[17]; + envp = &argv[argc + 1]; + __environ = envp; + +#ifndef NO_SHLIB + init_shlib (); +#endif + + /* Allocate 24 bytes of stack space for the register save area. */ + sp -= 24; + __libc_init (argc, argv, envp); + + exit (main (argc, argv, envp)); +} + +#ifndef NO_SHLIB + +/* System calls for use by the bootstrap routine. + These are defined here since the usual calls may be dynamically linked. */ + +int syscall (int sysno, ...) asm ("init_syscall"); +asm ("init_syscall:\n" + " clr %g1\n" + " ta 0\n" + " bcc 1f\n" + " sethi %hi(_errno), %g1\n" + " st %o0, [%g1 + %lo(_errno)]\n" + " sub %g0, 1, %o0\n" + "1:retl\n" + " nop"); + +static void +DEFUN_VOID(init_shlib) +{ + extern struct link_dynamic _DYNAMIC; + int so, zf; + caddr_t somap; + caddr_t sodmap; + caddr_t sobssmap; + void (*ldstart) (int, int); + struct exec soexec; + struct + { + caddr_t crt_ba; + int crt_dzfd; + int crt_ldfd; + struct link_dynamic *crt_dp; + char **crt_ep; + caddr_t crt_bp; + } soarg; + + /* If not dynamically linked, do nothing. */ + if (&_DYNAMIC == 0) + return; + + /* Map in the dynamic linker. */ + so = syscall (SYS_open, "/usr/lib/ld.so", O_RDONLY); + if (syscall (SYS_read, so, &soexec, sizeof (soexec)) != sizeof (soexec) + || soexec.a_magic != ZMAGIC) + { + static CONST char emsg[] = "crt0: no /usr/lib/ld.so\n"; + + syscall (SYS_write, 2, emsg, sizeof (emsg) - 1); + syscall (SYS_exit, 127); + } + somap = (caddr_t) syscall (SYS_mmap, 0, + soexec.a_text + soexec.a_data + soexec.a_bss, + PROT_READ | PROT_EXEC, _MAP_NEW | MAP_PRIVATE, + so, 0); + sodmap = (caddr_t) syscall (SYS_mmap, somap + soexec.a_text, soexec.a_data, + PROT_READ | PROT_WRITE | PROT_EXEC, + _MAP_NEW | MAP_FIXED | MAP_PRIVATE, + so, soexec.a_text); + zf = syscall (SYS_open, "/dev/zero", O_RDONLY); + if (soexec.a_bss != 0) + sobssmap = (caddr_t) syscall (SYS_mmap, + somap + soexec.a_text + soexec.a_data, + soexec.a_bss, + PROT_READ | PROT_WRITE | PROT_EXEC, + _MAP_NEW | MAP_FIXED | MAP_PRIVATE, + zf, 0); + + /* Call the entry point of the dynamic linker. */ + soarg.crt_ba = somap; + soarg.crt_dzfd = zf; + soarg.crt_ldfd = so; + soarg.crt_dp = &_DYNAMIC; + soarg.crt_ep = __environ; + soarg.crt_bp = (caddr_t) &&retaddr; + + ldstart = (__typeof (ldstart)) (somap + soexec.a_entry); + (*ldstart) (1, (char *) &soarg - (char *) sp); + + retaddr: +} + +#endif |