fpc/rtl/linux/x86_64/dllprt0.as

158 lines
4.7 KiB
ActionScript

#
# This file is part of the Free Pascal run time library.
# Copyright (c) 2006 by Florian Klaempfl
# 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
#
/* This is the canonical entry point, usually the first thing in the text
segment. The SVR4/i386 ABI (pages 3-31, 3-32) says that when the entry
point runs, most registers' values are unspecified, except for:
%rdx Contains a function pointer to be registered with `atexit'.
This is how the dynamic linker arranges to have DT_FINI
functions called for shared libraries that have been loaded
before this code runs.
%rsp The stack contains the arguments and environment:
0(%rsp) argc
8(%rsp) argv[0]
...
(8*argc)(%rsp) NULL
(8*(argc+1))(%rsp) envp[0]
...
NULL
*/
.section .init
.align 16
.globl FPC_SHARED_LIB_START
.type FPC_SHARED_LIB_START,@function
FPC_SHARED_LIB_START:
jmp _startlib@PLT
.text
.globl _startlib
.type _startlib,@function
_startlib:
movq entryinfo@GOTPCREL(%rip),%r10 /* load address of entryinfo variable */
movq %rdi,56(%r10)
movq %rsi,64(%r10) /* argv starts just at the current stack top */
movq %rdx,72(%r10)
/* Save initial stackpointer */
movq %rsp,80(%r10)
/* store stack length */
movq __stklen@GOTPCREL(%rip),%rax
movq %rax,88(%r10)
/* store pointer to _haltproc */
movq _haltproc@GOTPCREL(%rip),%rax
movq %rax,96(%r10)
/* populate the table pointers */
movq INITFINAL@GOTPCREL(%rip),%rax
movq %rax,(%r10)
movq FPC_THREADVARTABLES@GOTPCREL(%rip),%rax
movq %rax,8(%r10)
movq FPC_RESOURCESTRINGTABLES@GOTPCREL(%rip),%rax
movq %rax,16(%r10)
movq FPC_RESSTRINITTABLES@GOTPCREL(%rip),%rax
movq %rax,24(%r10)
movq FPC_RESLOCATION@GOTPCREL(%rip),%rax
movq %rax,32(%r10)
movq PASCALMAIN@GOTPCREL(%rip),%rax
movq %rax,40(%r10)
/* valgrind_used can stay 0 */
/* setup argument for FPC_SysEntry */
movq %r10,%rdi
movq operatingsystem_islibrary@GOTPCREL(%rip),%r10
movb $1,(%r10)
call FPC_SysEntry@PLT
ret
/* this routine is only called when the halt() routine of the RTL embedded in
the shared library is called */
.globl _haltproc
.type _haltproc,@function
_haltproc:
movl $231,%eax /* exit_group call */
movq operatingsystem_result@GOTPCREL(%rip),%rbx
movzwl (%rbx),%edi
syscall
jmp _haltproc@PLT
/* Define a symbol for the first piece of initialized data. */
.data
.globl __data_start
__data_start:
.long 0
.weak data_start
data_start = __data_start
.bss
/* the entry information looks like this:
TEntryInformation = record
InitFinalTable : Pointer; // offset 0
ThreadvarTablesTable : Pointer; // offset 8
ResourceStringTables : Pointer; // offset 16
ResStrInitTables : Pointer; // offset 24
ResLocation : Pointer; // offset 32
PascalMain : Procedure; // offset 40
valgrind_used : boolean; // offset 48
OS : TEntryInformationOS; // offset 56
end;
with TEntryInformationOS being
TEntryInformationOS = record
argc: longint; // offset 56
argv: ppchar; // offset 64
envp: ppchar; // offset 72
stkptr: pointer; // offset 80
stklen: sizeuint; // offset 88
haltproc: procedure(e:longint);cdecl; // offset 96
end;
The size of TEntryInformationOS including padding is 5 * sizeof(Pointer) = 40
The size of TEntryInformation including padding without OS is 8 * sizeof(Pointer) = 64
Thus the total size of TEntryInformation including padding is 104
*/
.comm entryinfo,104
/* We need this stuff to make gdb behave itself, otherwise
gdb will chokes with SIGILL when trying to debug apps.
Makes ld choke:
.section ".note.ABI-tag", "a"
.align 4
.long 1f - 0f
.long 3f - 2f
.long 1
0: .asciz "GNU"
1: .align 4
2: .long 0
.long 2,4,0
3: .align 4
*/
.section .note.GNU-stack,"",@progbits