NetBSD/lib/csu/hp300/crt0.c

133 lines
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C
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1993-05-13 17:50:54 +04:00
/*-
* Copyright (c) 1991 The Regents of the University of California.
* All rights reserved.
*
* 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 the University of
* California, Berkeley and its contributors.
* 4. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``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 REGENTS OR CONTRIBUTORS 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.
*/
#ifndef lint
static char sccsid[] = "@(#)crt0.c 5.6 (Berkeley) 7/3/91";
#endif /* not lint */
/*
* C start up routine.
* Robert Henry, UCB, 20 Oct 81
*
* We make the following (true) assumptions:
* 1) when the kernel calls start, it does a jump to location 2,
* and thus avoids the register save mask. We are NOT called
* with a calls! see sys1.c:setregs().
* 2) The only register variable that we can trust is sp,
* which points to the base of the kernel calling frame.
* Do NOT believe the documentation in exec(2) regarding the
* values of fp and ap.
* 3) We can allocate as many register variables as we want,
* and don't have to save them for anybody.
* 4) Because of the ways that asm's work, we can't have
* any automatic variables allocated on the stack, because
* we must catch the value of sp before any automatics are
* allocated.
*/
char **environ = (char **)0;
static int fd;
extern unsigned char etext;
extern unsigned char eprol asm ("eprol");
extern start() asm("start");
asm(".text; orb #0,d0"); /* 32 bits of zero at location 0 */
start()
{
struct kframe {
int kargc;
char *kargv[1]; /* size depends on kargc */
char kargstr[1]; /* size varies */
char kenvstr[1]; /* size varies */
};
/*
* ALL REGISTER VARIABLES!!!
*/
register struct kframe *kfp; /* r10 */
register char **targv;
register char **argv;
extern int errno;
extern void _mcleanup();
#ifdef lint
kfp = 0;
initcode = initcode = 0;
#else not lint
asm("lea a6@(4),%0" : "=r" (kfp)); /* catch it quick */
#endif not lint
for (argv = targv = &kfp->kargv[0]; *targv++; /* void */)
/* void */ ;
if (targv >= (char **)(*argv))
--targv;
environ = targv;
asm("eprol:");
#ifdef paranoid
/*
* The standard I/O library assumes that file descriptors 0, 1, and 2
* are open. If one of these descriptors is closed prior to the start
* of the process, I/O gets very confused. To avoid this problem, we
* insure that the first three file descriptors are open before calling
* main(). Normally this is undefined, as it adds two unnecessary
* system calls.
*/
do {
fd = open("/dev/null", 2);
} while (fd >= 0 && fd < 3);
close(fd);
#endif paranoid
#ifdef MCRT0
atexit(_mcleanup);
monstartup(&eprol, &etext);
#endif MCRT0
errno = 0;
exit(main(kfp->kargc, argv, environ));
}
#ifdef CRT0
/*
* null mcount and moncontrol,
* just in case some routine is compiled for profiling
*/
moncontrol(val)
int val;
{
}
asm(".globl mcount");
asm("mcount: rts");
#endif CRT0