Initial revision

From-SVN: r12679

gcc/config/i386/sol2-gc1.asm

+! gcrt1.s for Solaris 2, x86
+
+!   Copyright (C) 1993 Free Software Foundation, Inc.
+!   Written By Fred Fish, Nov 1992
+! 
+! This file is free software; you can redistribute it and/or modify it
+! under the terms of the GNU General Public License as published by the
+! Free Software Foundation; either version 2, or (at your option) any
+! later version.
+! 
+! In addition to the permissions in the GNU General Public License, the
+! Free Software Foundation gives you unlimited permission to link the
+! compiled version of this file with other programs, and to distribute
+! those programs without any restriction coming from the use of this
+! file.  (The General Public License restrictions do apply in other
+! respects; for example, they cover modification of the file, and
+! distribution when not linked into another program.)
+! 
+! This file 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
+! General Public License for more details.
+! 
+! You should have received a copy of the GNU General Public License
+! along with this program; see the file COPYING.  If not, write to
+! the Free Software Foundation, 59 Temple Place - Suite 330,
+! Boston, MA 02111-1307, USA.
+! 
+!    As a special exception, if you link this library with files
+!    compiled with GCC to produce an executable, this does not cause
+!    the resulting executable to be covered by the GNU General Public License.
+!    This exception does not however invalidate any other reasons why
+!    the executable file might be covered by the GNU General Public License.
+! 
+
+! This file takes control of the process from the kernel, as specified
+! in section 3 of the System V Application Binary Interface, Intel386
+! Processor Supplement.  It has been constructed from information obtained
+! from the ABI, information obtained from single stepping existing
+! Solaris executables through their startup code with gdb, and from
+! information obtained by single stepping executables on other i386 SVR4
+! implementations.  This file is the first thing linked into any executable.
+
+! This is a modified crt1.s by J.W.Hawtin <J.W.Hawtin@lboro.ac.uk> 15/8/96, 
+! to allow program profiling, by calling monstartup on entry and _mcleanup 
+! on exit
+
+	.file	"gcrt1.s"
+	.ident	"GNU C gcrt1.s"
+	.weak	_DYNAMIC
+	.text
+
+! Start creating the initial frame by pushing a NULL value for the return
+! address of the initial frame, and mark the end of the stack frame chain
+! (the innermost stack frame) with a NULL value, per page 3-32 of the ABI.
+! Initialize the first stack frame pointer in %ebp (the contents of which
+! are unspecified at process initialization).
+
+	.globl	_start
+_start:
+	pushl	$0x0
+	pushl	$0x0
+	movl	%esp,%ebp
+
+! As specified per page 3-32 of the ABI, %edx contains a function 
+! pointer that should be registered with atexit(), for proper
+! shared object termination.  Just push it onto the stack for now
+! to preserve it.  We want to register _cleanup() first.
+
+	pushl	%edx
+
+! Check to see if there is an _cleanup() function linked in, and if
+! so, register it with atexit() as the last thing to be run by
+! atexit().
+
+	movl	$_mcleanup,%eax
+	testl	%eax,%eax
+	je	.L1
+	pushl	$_mcleanup
+	call	atexit
+	addl	$0x4,%esp
+.L1:
+
+! Now check to see if we have an _DYNAMIC table, and if so then
+! we need to register the function pointer previously in %edx, but
+! now conveniently saved on the stack as the argument to pass to
+! atexit().
+
+	movl	$_DYNAMIC,%eax
+	testl	%eax,%eax
+	je	.L2
+	call	atexit
+.L2:
+
+! Register _fini() with atexit().  We will take care of calling _init()
+! directly.
+
+	pushl	$_fini
+	call	atexit
+
+! Start profiling
+
+        pushl %ebp
+        movl %esp,%ebp
+        pushl $_etext
+        pushl $_start
+        call monstartup
+        addl $8,%esp
+	popl %ebp
+
+! Compute the address of the environment vector on the stack and load
+! it into the global variable _environ.  Currently argc is at 8 off
+! the frame pointer.  Fetch the argument count into %eax, scale by the
+! size of each arg (4 bytes) and compute the address of the environment
+! vector which is 16 bytes (the two zero words we pushed, plus argc,
+! plus the null word terminating the arg vector) further up the stack,
+! off the frame pointer (whew!).
+
+	movl	8(%ebp),%eax
+	leal	16(%ebp,%eax,4),%edx
+	movl	%edx,_environ
+
+! Push the environment vector pointer, the argument vector pointer,
+! and the argument count on to the stack to set up the arguments
+! for _init(), _fpstart(), and main().  Note that the environment
+! vector pointer and the arg count were previously loaded into
+! %edx and %eax respectively.  The only new value we need to compute
+! is the argument vector pointer, which is at a fixed address off
+! the initial frame pointer.
+
+	pushl	%edx
+	leal	12(%ebp),%edx
+	pushl	%edx
+	pushl	%eax
+
+! Call _init(argc, argv, environ), _fpstart(argc, argv, environ), and
+! main(argc, argv, environ).
+
+	call	_init
+	call	__fpstart
+	call	main
+
+! Pop the argc, argv, and environ arguments off the stack, push the
+! value returned from main(), and call exit().
+
+	addl	$12,%esp
+	pushl	%eax
+	call	exit
+
+! An inline equivalent of _exit, as specified in Figure 3-26 of the ABI.
+
+	pushl	$0x0
+	movl	$0x1,%eax
+	lcall	$7,$0
+
+! If all else fails, just try a halt!
+
+	hlt
+	.type	_start,@function
+	.size	_start,.-_start