/* * Copyright (c) 1993 Paul Kranenburg * 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 Paul Kranenburg. * 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. * * $Id: crt0.c,v 1.13 1994/09/19 02:00:21 ache Exp $ */ #if defined(LIBC_SCCS) && !defined(lint) static char sccsid[] = "%W% (Erasmus) %G%"; #endif /* LIBC_SCCS and not lint */ extern void exit(); int _callmain(); #include #include #include extern void _startup_setlocale __P((int, const char *)); #ifdef DYNAMIC #include #include #include #ifndef N_GETMAGIC #define N_GETMAGIC(x) ((x).a_magic) #endif #ifndef N_BSSADDR #define N_BSSADDR(x) (N_DATADDR(x)+(x).a_data) #endif #include #ifdef sun #define MAP_COPY MAP_PRIVATE #define MAP_FILE 0 #define MAP_ANON 0 #else #ifdef BSD #if BSD>=199306 && !defined(MAP_FILE) #define MAP_FILE 0 #endif /* BSD>=199306 */ #endif /* BSD */ #endif /* sun */ #include extern struct _dynamic _DYNAMIC; static struct ld_entry *ld_entry; static void __do_dynamic_link (); static char *_getenv(); static int _strncmp(); #ifdef sun #define LDSO "/usr/lib/ld.so" #endif #ifdef BSD #define LDSO "/usr/libexec/ld.so" #endif #endif /* DYNAMIC */ static char *_strrchr(); char **environ; #ifdef BSD extern unsigned char etext; extern unsigned char eprol asm ("eprol"); extern start() asm("start"); extern mcount() asm ("mcount"); int errno; static char empty[1]; char *__progname = empty; #endif /* * We need these system calls, but can't use library stubs */ #define _exit(v) __syscall(SYS_exit, (int)(v)) #define open(name, f, m) __syscall(SYS_open, (char *)(name), (int)(f), (int)(m)) #define close(fd) __syscall(SYS_close, (int)(fd)) #define read(fd, s, n) __syscall(SYS_read, (int)(fd), (void *)(s), (size_t)(n)) #define write(fd, s, n) __syscall(SYS_write, (int)(fd), (void *)(s), (size_t)(n)) #define dup(fd) __syscall(SYS_dup, (int)(fd)) #define dup2(fd, fdnew) __syscall(SYS_dup2, (int)(fd), (int)(fdnew)) #ifdef sun #define mmap(addr, len, prot, flags, fd, off) \ __syscall(SYS_mmap, (addr), (len), (prot), _MAP_NEW|(flags), (fd), (off)) #else #define mmap(addr, len, prot, flags, fd, off) \ __syscall(SYS_mmap, (caddr_t)(addr), (size_t)(len), (int)(prot), (int)(flags), (int)(fd), (long)0L, (off_t)(off)) #endif #define _FATAL(str) \ write(2, str, sizeof(str)), \ _exit(1); 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; register char **targv; register char **argv; extern void _mcleanup(); #ifdef DYNAMIC volatile caddr_t x; #endif #ifdef lint kfp = 0; initcode = initcode = 0; #else /* not lint */ /* just above the saved frame pointer */ asm ("lea 4(%%ebp), %0" : "=r" (kfp) ); #endif /* not lint */ for (argv = targv = &kfp->kargv[0]; *targv++; /* void */) /* void */ ; if (targv >= (char **)(*argv)) --targv; environ = targv; if (argv[0]) if ((__progname = _strrchr(argv[0], '/')) == NULL) __progname = argv[0]; else ++__progname; #ifdef DYNAMIC /* ld(1) convention: if DYNAMIC = 0 then statically linked */ #ifdef stupid_gcc if (&_DYNAMIC) __do_dynamic_link(); #else x = (caddr_t)&_DYNAMIC; if (x) __do_dynamic_link(); #endif #endif /* DYNAMIC */ asm("eprol:"); #ifdef MCRT0 atexit(_mcleanup); monstartup(&eprol, &etext); #endif /* MCRT0 */ if (getenv("ENABLE_STARTUP_LOCALE") != NULL) _startup_setlocale(LC_ALL, ""); asm ("__callmain:"); /* Defined for the benefit of debuggers */ exit(main(kfp->kargc, argv, environ)); } #ifdef DYNAMIC static void __do_dynamic_link () { struct crt_ldso crt; struct exec hdr; char *ldso; int dupzfd; int (*entry)(); #ifdef DEBUG /* Provision for alternate ld.so - security risk! */ if (!(ldso = _getenv("LDSO"))) #endif ldso = LDSO; crt.crt_ldfd = open(ldso, 0, 0); if (crt.crt_ldfd == -1) { _FATAL("No ld.so\n"); } /* Read LDSO exec header */ if (read(crt.crt_ldfd, &hdr, sizeof hdr) < sizeof hdr) { _FATAL("Failure reading ld.so\n"); } if ((N_GETMAGIC_NET(hdr) != ZMAGIC) && (N_GETMAGIC(hdr) != QMAGIC)) { _FATAL("Bad magic: ld.so\n"); } /* We use MAP_ANON */ crt.crt_dzfd = -1; /* Map in ld.so */ crt.crt_ba = mmap(0, hdr.a_text, PROT_READ|PROT_EXEC, MAP_FILE|MAP_COPY, crt.crt_ldfd, N_TXTOFF(hdr)); if (crt.crt_ba == -1) { _FATAL("Cannot map ld.so\n"); } #ifdef BSD /* !!! * This is gross, ld.so is a ZMAGIC a.out, but has `sizeof(hdr)' for * an entry point and not at PAGSIZ as the N_*ADDR macros assume. */ #undef N_DATADDR #undef N_BSSADDR #define N_DATADDR(x) ((x).a_text) #define N_BSSADDR(x) ((x).a_text + (x).a_data) #endif /* Map in data segment of ld.so writable */ if (mmap(crt.crt_ba+N_DATADDR(hdr), hdr.a_data, PROT_READ|PROT_WRITE, MAP_FIXED|MAP_FILE|MAP_COPY, crt.crt_ldfd, N_DATOFF(hdr)) == -1) { _FATAL("Cannot map ld.so\n"); } /* Map bss segment of ld.so zero */ if (hdr.a_bss && mmap(crt.crt_ba+N_BSSADDR(hdr), hdr.a_bss, PROT_READ|PROT_WRITE, MAP_FIXED|MAP_ANON|MAP_COPY, crt.crt_dzfd, 0) == -1) { _FATAL("Cannot map ld.so\n"); } crt.crt_dp = &_DYNAMIC; crt.crt_ep = environ; crt.crt_bp = (caddr_t)_callmain; crt.crt_prog = __progname; entry = (int (*)())(crt.crt_ba + sizeof hdr); if ((*entry)(CRT_VERSION_BSD_3, &crt) == -1) { _FATAL("ld.so failed\n"); } ld_entry = _DYNAMIC.d_entry; return; } /* * DL stubs */ void * dlopen(name, mode) char *name; int mode; { if (ld_entry == NULL) return NULL; return (ld_entry->dlopen)(name, mode); } int dlclose(fd) void *fd; { if (ld_entry == NULL) return -1; return (ld_entry->dlclose)(fd); } void * dlsym(fd, name) void *fd; char *name; { if (ld_entry == NULL) return NULL; return (ld_entry->dlsym)(fd, name); } int dlctl(fd, cmd, arg) void *fd, *arg; int cmd; { if (ld_entry == NULL) return -1; return (ld_entry->dlctl)(fd, cmd, arg); } /* * Support routines */ static int _strncmp(s1, s2, n) register char *s1, *s2; register n; { if (n == 0) return (0); do { if (*s1 != *s2++) return (*(unsigned char *)s1 - *(unsigned char *)--s2); if (*s1++ == 0) break; } while (--n != 0); return (0); } static char * _getenv(name) register char *name; { extern char **environ; register int len; register char **P, *C; for (C = name, len = 0; *C && *C != '='; ++C, ++len); for (P = environ; *P; ++P) if (!_strncmp(*P, name, len)) if (*(C = *P + len) == '=') { return(++C); } return (char *)0; } asm(" ___syscall:"); asm(" popl %ecx"); asm(" popl %eax"); asm(" pushl %ecx"); asm(" .byte 0x9a"); asm(" .long 0"); asm(" .word 7"); asm(" pushl %ecx"); asm(" jc 1f"); asm(" ret"); asm(" 1:"); asm(" movl $-1,%eax"); asm(" ret"); #endif /* DYNAMIC */ static char * _strrchr(p, ch) register char *p, ch; { register char *save; for (save = NULL;; ++p) { if (*p == ch) save = (char *)p; if (!*p) return(save); } /* NOTREACHED */ } #ifdef MCRT0 asm (" .text"); asm ("_eprol:"); #endif