diff options
Diffstat (limited to 'libc/sysdeps/linux')
| -rw-r--r-- | libc/sysdeps/linux/i386/Makefile | 12 | ||||
| -rw-r--r-- | libc/sysdeps/linux/i386/crt0.S | 123 | 
2 files changed, 133 insertions, 2 deletions
diff --git a/libc/sysdeps/linux/i386/Makefile b/libc/sysdeps/linux/i386/Makefile index 9c487bfd1..a6b185c21 100644 --- a/libc/sysdeps/linux/i386/Makefile +++ b/libc/sysdeps/linux/i386/Makefile @@ -25,7 +25,10 @@ include $(TOPDIR)Rules.mak  LIBC=$(TOPDIR)libc.a  ASFLAGS=$(CFLAGS) -SSRC=_start.S longjmp.S setjmp.S #_start.S #clone.S +CRT0=crt0.S +CRT0_OBJ=$(patsubst %.S,%.o, $(CRT0)) + +SSRC=longjmp.S setjmp.S #_start.S #clone.S  ifeq ($(UNIFIED_SYSCALL),true)  	SSRC += __uClibc_syscall.S  endif @@ -37,13 +40,18 @@ COBJS=$(patsubst %.c,%.o, $(CSRC))  OBJS=$(SOBJS) $(COBJS) -all: $(OBJS) $(LIBC) +all: $(OBJS) $(CRT0_OBJ) $(LIBC)  $(LIBC): ar-target  ar-target: $(OBJS)  	$(AR) $(ARFLAGS) $(LIBC) $(OBJS) +$(CRT0_OBJ): %.o : %.S +	$(CC) $(CFLAGS) -c $< -o $@ +	$(STRIPTOOL) -x -R .note -R .comment $*.o +	cp $*.o $(TOPDIR)/libcrt0.o +  $(SOBJS): %.o : %.S  	$(CC) $(CFLAGS) -c $< -o $@  	$(STRIPTOOL) -x -R .note -R .comment $*.o diff --git a/libc/sysdeps/linux/i386/crt0.S b/libc/sysdeps/linux/i386/crt0.S new file mode 100644 index 000000000..08e406cc6 --- /dev/null +++ b/libc/sysdeps/linux/i386/crt0.S @@ -0,0 +1,123 @@ +/* Copyright (C) 1991, 1992 Free Software Foundation, Inc. +This file is part of the GNU C Library. + +The GNU C Library is free software; you can redistribute it and/or +modify it under the terms of the GNU Library General Public License as +published by the Free Software Foundation; either version 2 of the +License, or (at your option) any later version. + +The GNU C Library is distributed in the hope that it will be useful, +but WITHOUT ANY WARRANTY; without even the implied warranty of +MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU +Library General Public License for more details. + +You should have received a copy of the GNU Library General Public +License along with the GNU C Library; see the file COPYING.LIB.  If +not, write to the Free Software Foundation, Inc., 675 Mass Ave, +Cambridge, MA 02139, USA.  */ + + +/*  If you don't know what is going on here, check out  +    http://linuxassembly.org/startup.html +    For a description of the stack layout. +     -John Beppu, and Erik Andersen +*/ + +.global __environ +.global __errno +.global _start +.global exit +.global main +.global __stdio_close_all +.global _void_void_null_func +.global _start_exit + +.text +_start: +	/* First locate the start of the environment variables */ +	popl %ecx	/* Store argc into %ecx */ +	movl %esp,%ebx  /* Store argv into ebx */ +	movl %esp,%eax  /* Store argv into eax as well*/ +	movl %ecx,%edx	/* Stick argc into %edx so we can do some math in a sec */ +	leal 4(%eax,%edx,4),%eax + +	/*  [ register layout ] + +	    sizeof(char*) == 4 +	    %ecx = argc	    ; 0(esp) +	    %ebx = argv	    ; 4(esp) +	    %eax = env	    ; argv + (argc * 4) + 4 +	*/ + + +	/* Set up an invalid (NULL return address, NULL frame pointer) +	   callers stack frame so anybody unrolling the stack knows where +	   to stop */ +	xorl %ebp,%ebp  /* NULL */ +	pushl %ebp      /* callers %cs */ +	pushl %ebp      /* callers %eip (return address) */ +	pushl %ebp      /* callers %ebp (frame pointer) */ +	movl %esp,%ebp  /* mark callers stack frame as invalid */ + +	/* Now set the environment, argc, and argv where the app can get to them */ +	pushl %eax      /* Environment pointer */ +	pushl %ebx       /* Argument pointer */ +	pushl %ecx      /* And the argument count */ + +	/* Make sure we are not using iBCS2 personality. (i.e. force linux).  */ +	movl $136,%eax +	sub %ebx,%ebx +	int $0x80 + +	/* set up __environ */	 +	movl 8(%esp),%eax +	movl %eax,__environ + +	/* Tell libc to initialize anything it needs to do */ +	call __libc_init +	/* call __malloc_init */ +	call __init_stdio + +	/* Ok, now run main() */ +	call main +	pushl %eax +	call exit + +	/* Just in case _exit fails... We use int $0x80 for __exit().  */ +	popl %ebx +	.align 4,0x90 +_start_exit: +	movl $1,%eax +	int $0x80 +	jmp _start_exit +	.align 4,0x90 +_void_void_null_func: +	ret + +.weak __libc_init +__libc_init = _void_void_null_func + +/* +.weak __malloc_init +__malloc_init = _void_void_null_func +*/ + +.weak __init_stdio +__init_stdio = _void_void_null_func + +.weak __stdio_close_all +__stdio_close_all = _void_void_null_func +	 +.data +__environ: +        .long 0 +.weak environ +.align  4 +environ = __environ + +.data +__errno: +        .long 0 +.weak errno +.align  4 +errno = __errno  | 
