| 1 | /*- |
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| 2 | * Copyright (c) 1990 The Regents of the University of California. |
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| 3 | * All rights reserved. |
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| 4 | * |
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| 5 | * Redistribution and use in source and binary forms, with or without |
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| 6 | * modification, are permitted provided that the following conditions |
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| 7 | * are met: |
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| 8 | * 1. Redistributions of source code must retain the above copyright |
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| 9 | * notice, this list of conditions and the following disclaimer. |
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| 10 | * 2. Redistributions in binary form must reproduce the above copyright |
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| 11 | * notice, this list of conditions and the following disclaimer in the |
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| 12 | * documentation and/or other materials provided with the distribution. |
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| 13 | * 3. All advertising materials mentioning features or use of this software |
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| 14 | * must display the following acknowledgement: |
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| 15 | * This product includes software developed by the University of |
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| 16 | * California, Berkeley and its contributors. |
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| 17 | * 4. Neither the name of the University nor the names of its contributors |
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| 18 | * may be used to endorse or promote products derived from this software |
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| 19 | * without specific prior written permission. |
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| 20 | * |
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| 21 | * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND |
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| 22 | * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE |
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| 23 | * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE |
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| 24 | * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE |
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| 25 | * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL |
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| 26 | * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS |
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| 27 | * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) |
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| 28 | * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT |
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| 29 | * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY |
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| 30 | * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF |
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| 31 | * SUCH DAMAGE. |
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| 32 | */ |
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| 33 | |
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| 34 | #if defined(LIBC_SCCS) && !defined(lint) |
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| 35 | static char sccsid[] = "@(#)crt0.c 5.7 (Berkeley) 7/3/91"; |
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| 36 | #endif /* LIBC_SCCS and not lint */ |
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| 37 | |
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| 38 | /* |
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| 39 | * C start up routine. |
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| 40 | * Robert Henry, UCB, 20 Oct 81 |
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| 41 | * |
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| 42 | * We make the following (true) assumption: |
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| 43 | * 1) The only register variable that we can trust is ebp, |
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| 44 | * which points to the base of the kernel calling frame. |
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| 45 | */ |
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| 46 | |
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| 47 | char **environ = (char **)0; |
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| 48 | static int fd; |
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| 49 | |
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| 50 | /* |
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| 51 | asm(".text"); |
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| 52 | asm(".long 0xc000c000"); |
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| 53 | */ |
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| 54 | extern unsigned char etext; |
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| 55 | extern unsigned char eprol asm ("eprol"); |
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| 56 | /* extern start() asm("start"); */ |
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| 57 | |
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| 58 | _start(int arg) |
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| 59 | { |
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| 60 | struct kframe { |
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| 61 | int kargc; |
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| 62 | char *kargv[1]; /* size depends on kargc */ |
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| 63 | char kargstr[1]; /* size varies */ |
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| 64 | char kenvstr[1]; /* size varies */ |
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| 65 | }; |
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| 66 | /* |
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| 67 | * ALL REGISTER VARIABLES!!! |
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| 68 | */ |
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| 69 | register struct kframe *kfp; /* r10 */ |
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| 70 | register char **targv; |
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| 71 | register char **argv; |
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| 72 | extern int errno; |
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| 73 | extern void _mcleanup(); |
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| 74 | |
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| 75 | #ifdef lint |
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| 76 | kfp = 0; |
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| 77 | initcode = initcode = 0; |
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| 78 | #else not lint |
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| 79 | # if 0 |
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| 80 | asm("lea 4(%ebp),%ebx"); /* catch it quick */ |
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| 81 | # else |
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| 82 | kfp = (struct kframe *)&(((int *)(&arg))[-1]); |
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| 83 | # endif |
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| 84 | #endif not lint |
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| 85 | for (argv = targv = &kfp->kargv[0]; *targv++; /* void */) |
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| 86 | /* void */ ; |
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| 87 | if (targv >= (char **)(*argv)) |
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| 88 | --targv; |
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| 89 | environ = targv; |
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| 90 | asm("eprol:"); |
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| 91 | |
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| 92 | #ifdef paranoid |
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| 93 | /* |
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| 94 | * The standard I/O library assumes that file descriptors 0, 1, and 2 |
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| 95 | * are open. If one of these descriptors is closed prior to the start |
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| 96 | * of the process, I/O gets very confused. To avoid this problem, we |
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| 97 | * insure that the first three file descriptors are open before calling |
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| 98 | * main(). Normally this is undefined, as it adds two unnecessary |
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| 99 | * system calls. |
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| 100 | */ |
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| 101 | do { |
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| 102 | fd = open("/dev/null", 2); |
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| 103 | } while (fd >= 0 && fd < 3); |
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| 104 | close(fd); |
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| 105 | #endif paranoid |
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| 106 | |
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| 107 | #ifdef MCRT0 |
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| 108 | atexit(_mcleanup); |
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| 109 | monstartup(&eprol, &etext); |
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| 110 | #endif MCRT0 |
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| 111 | errno = 0; |
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| 112 | exit(main(kfp->kargc, argv, environ)); |
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| 113 | } |
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| 114 | |
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| 115 | #ifdef CRT0 |
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| 116 | /* |
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| 117 | * null mcount and moncontrol, |
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| 118 | * just in case some routine is compiled for profiling |
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| 119 | */ |
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| 120 | moncontrol(val) |
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| 121 | int val; |
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| 122 | { |
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| 123 | |
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| 124 | } |
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| 125 | asm(".globl mcount"); |
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| 126 | asm("mcount: ret"); |
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| 127 | #endif CRT0 |
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