e83f7ba2c9
. file- and functionality-compatible with previous situation (FreeBSD csu) (with a crt1.o -> crt0.o symlink in /usr/lib) . harmonizes source with netbsd . harmonizes linker invocation (e.g. clang) with netbsd . helpful to get some arm code in there for the arm port project
169 lines
4.9 KiB
C
169 lines
4.9 KiB
C
/* $NetBSD: crt0.c,v 1.20 2009/12/14 01:04:02 matt Exp $ */
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/*
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* Copyright (c) 1995 Christopher G. Demetriou
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* All rights reserved.
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*
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* Modifications for NetBSD/mips:
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*
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* Jonathan Stone
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* Jason R. Thorpe, Numerical Aerospace Simulation Facility,
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* NASA Ames Research Center
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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* 3. All advertising materials mentioning features or use of this software
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* must display the following acknowledgement:
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* This product includes software developed by Christopher G. Demetriou
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* for the NetBSD Project.
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* 4. The name of the author may not be used to endorse or promote products
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* derived from this software without specific prior written permission
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*
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* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
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* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
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* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
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* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
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* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
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* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
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* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
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* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
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* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
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* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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*/
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#include "common.h"
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/*
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* C start-up. Assumes kernel (or ld.so) passes the
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* following parameters to user-space in registers:
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*
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* a0 stack pointer (0 if setregs didn't fill this in)
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* a1 cleanup
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* a2 Obj_Entry
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* a3 ps_strings
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*
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* XXX Does this violate the ABI?
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* as well as the usual registers (pc, sp, and t9 == pc for ABI).
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*/
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void __start(u_long, void (*)(void), const Obj_Entry *,
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struct ps_strings *);
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__asm(".text; .align 4; .globl _start; _start:");
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void
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__start(u_long sp,
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void (*cleanup)(void), /* from shared loader */
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const Obj_Entry *obj, /* from shared loader */
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struct ps_strings *ps_strings)
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{
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char **ksp;
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char **argv, *namep;
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int argc;
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/*
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* Grab the argc, argv, and envp set up by the kernel.
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* Layout of stuff on the stack:
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*
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* [ high ]
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* char kenvstr[1]; // size varies
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* char kargstr[1]; // size varies
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* char *argv[1]; // varies on argc
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* int argc;
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* [ low ] <--- kernel's SP points here
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* .
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* .
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* .
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* [ current stack pointer ]
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*
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* WARNING! There is an implicit sizeof(int) == sizeof(char *) here!
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*/
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#ifndef DYNAMIC
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#ifdef _LP64
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__asm volatile("dla $28,_gp");
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#else
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__asm volatile("la $28,_gp");
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#endif
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#endif
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ksp = (char**)sp;
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#if defined(__mips_n32) || defined(__mips_n64)
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if (ksp == 0) {
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/*
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* Uh, oh. We're running on a old kernel that passed
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* us zero in $a0-$a3. Try adjusting the current
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* $sp for our own stack-frame size and see what
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* we find.
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* WARNING! The constants 56 and 64 below were determined
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* by examining GCC assembler output of __start to find the
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* frame size. If you change the code or compiler,
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* you _will_ lose!
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*/
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#ifndef DYNAMIC
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/* XXX 56 is compiler and stackframe dependent */
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__asm volatile(" addiu %0,$29,56" : "=r" (ksp));
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#else
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/* XXX 64 is compiler and stackframe dependent */
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__asm volatile(" addiu %0,$29,64" : "=r" (ksp));
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#endif
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}
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#endif
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argc = *(int *)ksp;
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argv = ksp + 1;
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environ = ksp + 2 + argc; /* 2: argc + NULL ending argv */
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if ((namep = argv[0]) != NULL) { /* NULL ptr if argc = 0 */
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if ((__progname = _strrchr(namep, '/')) == NULL)
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__progname = namep;
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else
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__progname++;
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}
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/*
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* Deal with stuff that is only provided if setregs() did
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* did the right thing.
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*/
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if (sp != 0) {
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if (ps_strings != (struct ps_strings *)0)
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__ps_strings = ps_strings;
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#ifdef DYNAMIC
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/*
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* XXX Old MIPS ld.so didn't do any of this at all.
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* XXX If we were loaded by that loader, just abort
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* XXX the rtld setup.
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*/
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if (&_DYNAMIC != NULL && cleanup != NULL && obj != NULL)
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_rtld_setup(cleanup, obj);
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#endif
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}
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#ifdef MCRT0
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atexit(_mcleanup);
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monstartup((u_long)&_eprol, (u_long)&_etext);
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#endif
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atexit(_fini);
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_init();
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exit(main(argc, argv, environ));
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}
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/*
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* RCSid. Place after __start for programs that assume start of text
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* is the entrypoint. (Only needed for old toolchains).
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*/
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#if defined(LIBC_SCCS) && !defined(lint)
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__RCSID("$NetBSD: crt0.c,v 1.20 2009/12/14 01:04:02 matt Exp $");
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#endif /* LIBC_SCCS and not lint */
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#include "common.c"
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