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author | Jim Wilson <wilson@gcc.gnu.org> | 1993-02-05 15:50:44 -0800 |
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committer | Jim Wilson <wilson@gcc.gnu.org> | 1993-02-05 15:50:44 -0800 |
commit | 266f95411b8044ac934e19580de1d25b481aa06f (patch) | |
tree | 40ae571f75eb13d2ee3a90b2876fc589c18fea5e /gcc/config/i386/sol2-c1.asm | |
parent | d68398271cd3079fa4536fc0241ce7d6bbab6b2d (diff) | |
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Initial revision
From-SVN: r3431
Diffstat (limited to 'gcc/config/i386/sol2-c1.asm')
-rw-r--r-- | gcc/config/i386/sol2-c1.asm | 155 |
1 files changed, 155 insertions, 0 deletions
diff --git a/gcc/config/i386/sol2-c1.asm b/gcc/config/i386/sol2-c1.asm new file mode 100644 index 0000000..bd7c737 --- /dev/null +++ b/gcc/config/i386/sol2-c1.asm @@ -0,0 +1,155 @@ +! crt1.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, 675 Mass Ave, Cambridge, MA 02139, 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. + + .file "crt1.s" + .ident "GNU C crt1.s" + .weak _cleanup + .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 $_cleanup,%eax + testl %eax,%eax + je .L1 + pushl $_cleanup + 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 + +! 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 + +! A dummy profiling support routine for non-profiling executables, +! in case we link in some objects that have been compiled for profiling. + + .globl _mcount +_mcount: + ret + .type _mcount,@function + .size _mcount,.-_mcount |