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{
This file is part of the Free Pascal run time library.
Copyright (c) 2005 by Michael Van Canneyt, Peter Vreman,
& Daniel Mantione, members of the Free Pascal development team.
See the file COPYING.FPC, included in this distribution,
for details about the copyright.
This program 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.
**********************************************************************}
{
Linux ELF startup code for Free Pascal
Stack layout at program start:
nil
envn
....
.... ENVIRONMENT VARIABLES
env1
env0
nil
argn
....
.... COMMAND LINE OPTIONS
arg1
arg0
argc <--- esp
}
var
libc_environ: pchar; external name '__environ';
libc_fpu_control: word; external name '__fpu_control';
libc_init_proc: procedure; external name '_init';
libc_fini_proc: procedure; external name '_fini';
procedure libc_atexit; external name '__libc_atexit';
procedure libc_exit; external name '__libc_exit';
procedure libc_init; external name '__libc_init';
procedure libc_setfpucw; external name '__setfpucw';
procedure libc_start_main; external name '__libc_start_main';
procedure PASCALMAIN; external name 'PASCALMAIN';
Procedure fpc_geteipasebx;[external name 'fpc_geteipasebx'];
{******************************************************************************
C library start/halt
******************************************************************************}
{$asmmode ATT}
procedure _FPC_libc_start; assembler; nostackframe; public name '_start';
asm
{ First locate the start of the environment variables }
popl %ecx { Get argc in ecx }
{$ifdef FPC_PIC}
movl %esp,%ebp { Points to the arguments }
movl %ecx,%esi
{$else FPC_PIC}
movl %esp,%ebx { Points to the arguments }
{$endif FPC_PIC}
leal 4(%esp,%ecx,4),%eax { The start of the environment is: esp+4*eax+8 }
andl $0xfffffff8,%esp { Align stack }
{$ifdef FPC_PIC}
pushl %ecx
call fpc_geteipasebx
addl $_GLOBAL_OFFSET_TABLE_,%ebx
movl operatingsystem_parameter_envp@GOT(%ebx),%ecx
movl %eax,(%ecx)
movl libc_environ@GOT(%ebx),%ecx
movl %eax,(%ecx)
pushl %eax
movl operatingsystem_parameter_argc@GOT(%ebx),%ecx
movl %esi,%eax
movl %eax,(%ecx)
movl operatingsystem_parameter_argv@GOT(%ebx),%ecx
movl %ebp,%eax
movl %eax,(%ecx)
popl %eax
popl %ecx
movl %ebp,%ebx
{$else FPC_PIC}
movl %eax,operatingsystem_parameter_envp { Move the environment pointer }
movl %ecx,operatingsystem_parameter_argc { Move the argument counter }
movl %ebx,operatingsystem_parameter_argv { Move the argument pointer }
movl %eax,libc_environ { libc environ }
{$endif FPC_PIC}
pushl %eax
pushl %ebx
pushl %ecx
call libc_init { init libc }
{$ifdef FPC_PIC}
pushl %ecx
pushl %ebx
call fpc_geteipasebx
addl $_GLOBAL_OFFSET_TABLE_,%ebx
movl libc_init_proc@GOT(%ebx),%ecx
movl (%ecx),%edi
popl %ebx
popl %ecx
{$else FPC_PIC}
movzwl libc_fpu_control,%eax
{$endif FPC_PIC}
pushl %eax
call libc_setfpucw
popl %eax
pushl $libc_fini_proc
call libc_atexit
popl %eax
{$ifdef FPC_PIC}
call *%edi
{$else FPC_PIC}
call libc_init_proc
{$endif FPC_PIC}
popl %eax
popl %eax
{ Save initial stackpointer }
{$ifdef FPC_PIC}
pushl %ecx
pushl %ebx
call fpc_geteipasebx
addl $_GLOBAL_OFFSET_TABLE_,%ebx
movl initialstkptr@GOT(%ebx),%ecx
movl %esp,(%ecx)
popl %ebx
popl %ecx
{$else FPC_PIC}
movl %esp,initialstkptr
{$endif FPC_PIC}
xorl %ebp,%ebp
call PASCALMAIN { start the program }
end;
procedure _FPC_libc_haltproc; assembler; nostackframe; public name '_haltproc';
asm
.Lhaltproc:
{$ifdef FPC_PIC}
call fpc_geteipasebx
addl $_GLOBAL_OFFSET_TABLE_,%ebx
movl ExitCode@GOT(%ebx),%ebx
{$if sizeof(ExitCode)=2}
movzwl (%ebx),%ebx
{$else}
mov (%ebx),%ebx
{$endif}
{$else FPC_PIC}
{$if sizeof(ExitCode)=2}
movzwl ExitCode,%ebx
{$else}
mov ExitCode,%ebx
{$endif}
{$endif FPC_PIC}
pushl %ebx
call libc_exit
xorl %eax,%eax
incl %eax { eax=1, exit call }
popl %ebx
int $0x80
jmp .Lhaltproc
end;
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