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authorRoland McGrath <roland@gnu.org>1995-02-18 01:27:10 +0000
committerRoland McGrath <roland@gnu.org>1995-02-18 01:27:10 +0000
commit28f540f45bbacd939bfd07f213bcad2bf730b1bf (patch)
tree15f07c4c43d635959c6afee96bde71fb1b3614ee /sysdeps/unix/sparc/start.c
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initial import
Diffstat (limited to 'sysdeps/unix/sparc/start.c')
-rw-r--r--sysdeps/unix/sparc/start.c184
1 files changed, 184 insertions, 0 deletions
diff --git a/sysdeps/unix/sparc/start.c b/sysdeps/unix/sparc/start.c
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+++ b/sysdeps/unix/sparc/start.c
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+/* 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