NetBSD/lib/csu/mips/crt0.c

321 lines
7.6 KiB
C

/* $NetBSD: crt0.c,v 1.9 1998/07/25 04:45:04 mycroft Exp $ */
/*
* Copyright (c) 1995 Christopher G. Demetriou
* All rights reserved.
*
* Modifications for NetBSD/mips:
*
* Jonathan Stone
* Jason R. Thorpe, Numerical Aerospace Simulation Facility,
* NASA Ames Research Center
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by Christopher G. Demetriou
* for the NetBSD Project.
* 4. The name of the author may not be used to endorse or promote products
* derived from this software without specific prior written permission
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#ifdef ECOFF_COMPAT
#undef DYNAMIC
#endif
#include <sys/types.h>
#include <sys/exec.h>
#include <sys/syscall.h>
#include <stdlib.h>
#ifdef DYNAMIC
#include <dlfcn.h>
#include "rtld.h"
#else
typedef void Obj_Entry;
#endif
/*
* Lots of the chunks of this file cobbled together from pieces of
* other NetBSD crt files, including the common code.
*/
extern int __syscall __P((int, ...));
#define _exit(v) __syscall(SYS_exit, (v))
#define write(fd, s, n) __syscall(SYS_write, (fd), (s), (n))
#define _FATAL(str) \
do { \
write(2, str, sizeof(str)); \
_exit(1); \
} while (0)
static char *_strrchr __P((char *, char));
char **environ;
char *__progname = "";
struct ps_strings *__ps_strings = 0;
#ifndef ECOFF_COMPAT
extern void __init __P((void));
extern void __fini __P((void));
#endif /* ECOFF_COMPAT */
#ifdef DYNAMIC
void rtld_setup __P((void (*)(void), const Obj_Entry *obj));
const Obj_Entry *__mainprog_obj;
/*
* Arrange for _DYNAMIC to be weak and undefined (and therefore to show up
* as being at address zero, unless something else defines it). That way,
* if we happen to be compiling without -static but with without any
* shared libs present, things will still work.
*/
asm(".weak _DYNAMIC");
extern int _DYNAMIC;
#endif /* DYNAMIC */
#ifdef MCRT0
extern void monstartup __P((u_long, u_long));
extern void _mcleanup __P((void));
extern unsigned char _etext, _eprol;
#endif /* MCRT0 */
/*
* C start-up. Assumes kernel (or ld.so) passes the
* following parameters to user-space in registers:
*
* a0 stack pointer (0 if setregs didn't fill this in)
* a1 cleanup
* a2 Obj_Entry
* a3 ps_strings
*
* XXX Does this violate the ABI?
* as well as the usual registers (pc, sp, and t9 == pc for ABI).
*/
void __start __P((u_long, void (*) __P((void)), const Obj_Entry *,
struct ps_strings *));
asm(".text; .align 4; .globl _start; _start:");
void
__start(sp, cleanup, obj, ps_strings)
u_long sp;
void (*cleanup) __P((void)); /* from shared loader */
const Obj_Entry *obj; /* from shared loader */
struct ps_strings *ps_strings;
{
char **ksp;
char **argv, *namep;
int argc;
/*
* Grab the argc, argv, and envp set up by the kernel.
* Layout of stuff on the stack:
*
* [ high ]
* char kenvstr[1]; // size varies
* char kargstr[1]; // size varies
* char *argv[1]; // varies on argc
* int argc;
* [ low ] <--- kernel's SP points here
* .
* .
* .
* [ current stack pointer ]
*
* WARNING! There is an implicit sizeof(int) == sizeof(char *) here!
*/
#ifndef DYNAMIC
__asm __volatile("la $28,_gp");
#endif
ksp = (char**)sp;
if (ksp == 0) {
/*
* Uh, oh. We're running on a old kernel that passed
* us zero in $a0-$a3. Try adjusting the current
* $sp for our own stack-frame size and see what
* we find.
* WARNING! The constants 56 and 64 below were determined
* by examining GCC assembler output of __start to find the
* frame size. If you change the code or compiler,
* you _will_ lose!
*/
#ifndef DYNAMIC
/* XXX 56 is compiler and stackframe dependent */
__asm __volatile(" addiu %0,$29,56" : "=r" (ksp));
#else
/* XXX 64 is compiler and stackframe dependent */
__asm __volatile(" addiu %0,$29,64" : "=r" (ksp));
#endif
}
argc = *(int *)ksp;
argv = ksp + 1;
environ = ksp + 2 + argc; /* 2: argc + NULL ending argv */
if ((namep = argv[0]) != NULL) { /* NULL ptr if argc = 0 */
if ((__progname = _strrchr(namep, '/')) == NULL)
__progname = namep;
else
__progname++;
}
/*
* Deal with stuff that is only provided if setregs() did
* did the right thing.
*/
if (sp != 0) {
if (ps_strings != (struct ps_strings *)0)
__ps_strings = ps_strings;
#ifdef DYNAMIC
/*
* XXX Old MIPS ld.so didn't do any of this at all.
* XXX If we were loaded by that loader, just abort
* XXX the rtld setup.
*/
if (&_DYNAMIC != NULL && cleanup != NULL && obj != NULL)
rtld_setup(cleanup, obj);
#endif
}
#ifdef MCRT0
atexit(_mcleanup);
monstartup((u_long)&_eprol, (u_long)&_etext);
#endif
/* XXX __fini and __init are not yet on a MIPS. */
#if 0
#ifndef ECOFF_COMPAT
atexit(__fini);
__init();
#endif /* ECOFF_COMPAT */
#endif
exit(main(argc, argv, environ));
}
/*
* RCSid. Place after __start for programs that assume start of text
* is the entrypoint. (Only needed for old toolchains).
*/
#if defined(LIBC_SCCS) && !defined(lint)
__RCSID("$NetBSD: crt0.c,v 1.9 1998/07/25 04:45:04 mycroft Exp $");
#endif /* LIBC_SCCS and not lint */
static char *
_strrchr(p, ch)
char *p, ch;
{
char *save;
for (save = NULL; ; ++p) {
if (*p == ch)
save = (char *)p;
if (!*p)
return(save);
}
/* NOTREACHED */
}
#ifdef MCRT0
asm (" .text");
asm ("_eprol:");
#endif
#ifdef DYNAMIC
void
rtld_setup(cleanup, obj)
void (*cleanup) __P((void));
const Obj_Entry *obj;
{
if ((obj == NULL) || (obj->magic != RTLD_MAGIC))
_FATAL("Corrupt Obj_Entry pointer in GOT");
if (obj->version != RTLD_VERSION)
_FATAL("Dynamic linker version mismatch");
__mainprog_obj = obj;
atexit(cleanup);
}
void *
dlopen(name, mode)
const char *name;
int mode;
{
if (__mainprog_obj == NULL)
return NULL;
return (__mainprog_obj->dlopen)(name, mode);
}
int
dlclose(fd)
void *fd;
{
if (__mainprog_obj == NULL)
return -1;
return (__mainprog_obj->dlclose)(fd);
}
void *
dlsym(fd, name)
void *fd;
const char *name;
{
if (__mainprog_obj == NULL)
return NULL;
return (__mainprog_obj->dlsym)(fd, name);
}
#if 0 /* not supported for ELF shlibs, apparently */
int
dlctl(fd, cmd, arg)
void *fd, *arg;
int cmd;
{
if (__mainprog_obj == NULL)
return -1;
return (__mainprog_obj->dlctl)(fd, cmd, arg);
}
#endif
char *
dlerror()
{
if (__mainprog_obj == NULL)
return NULL;
return (__mainprog_obj->dlerror)();
}
#endif /* DYNAMIC */