|
|
@@ -0,0 +1,161 @@
|
|
|
+{
|
|
|
+ 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';
|
|
|
+
|
|
|
+ fpc_ret,fpc_ret_rbp : pointer;
|
|
|
+
|
|
|
+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 main_stub; assembler; nostackframe;
|
|
|
+ asm
|
|
|
+ { save return address }
|
|
|
+ popq %rax
|
|
|
+
|
|
|
+ // stack alignment
|
|
|
+ pushq %rax
|
|
|
+
|
|
|
+ movq %rax,fpc_ret
|
|
|
+ movq %rbp,fpc_ret_rbp
|
|
|
+ pushq %rax
|
|
|
+
|
|
|
+ { Save initial stackpointer }
|
|
|
+ movq %rsp,__stkptr
|
|
|
+
|
|
|
+ { start the program }
|
|
|
+ xorq %rbp,%rbp
|
|
|
+ call PASCALMAIN
|
|
|
+ hlt
|
|
|
+ end;
|
|
|
+
|
|
|
+
|
|
|
+procedure ini_dummy; assembler; nostackframe
|
|
|
+ asm
|
|
|
+ ret
|
|
|
+ end;
|
|
|
+
|
|
|
+{******************************************************************************
|
|
|
+ C library start/halt
|
|
|
+ ******************************************************************************}
|
|
|
+
|
|
|
+procedure _FPC_libc_start; assembler; nostackframe; public name '_start';
|
|
|
+ asm
|
|
|
+ { Clear the frame pointer. The ABI suggests this be done, to mark
|
|
|
+ the outermost frame obviously. }
|
|
|
+ xorq %rbp, %rbp
|
|
|
+
|
|
|
+ { Extract the arguments as encoded on the stack and set up
|
|
|
+ the arguments for __libc_start_main (int (*main) (int, char **, char **),
|
|
|
+ int argc, char *argv,
|
|
|
+ void (*init) (void), void (*fini) (void),
|
|
|
+ void (*rtld_fini) (void), void *stack_end).
|
|
|
+ The arguments are passed via registers and on the stack:
|
|
|
+ main: %rdi
|
|
|
+ argc: %rsi
|
|
|
+ argv: %rdx
|
|
|
+ init: %rcx
|
|
|
+ fini: %r8
|
|
|
+ rtld_fini: %r9
|
|
|
+ stack_end: stack. }
|
|
|
+
|
|
|
+ movq %rdx, %r9 { Address of the shared library termination
|
|
|
+ function. }
|
|
|
+ popq %rsi { Pop the argument count. }
|
|
|
+ movq %rsp, %rdx { argv starts just at the current stack top. }
|
|
|
+
|
|
|
+ movq %rsi,operatingsystem_parameter_argc
|
|
|
+ movq %rsp,operatingsystem_parameter_argv { argv starts just at the current stack top. }
|
|
|
+ leaq 8(,%rsi,8),%rax
|
|
|
+ addq %rsp,%rax
|
|
|
+ movq %rax,operatingsystem_parameter_envp
|
|
|
+
|
|
|
+ { Align the stack to a 16 byte boundary to follow the ABI. }
|
|
|
+ andq $~15, %rsp
|
|
|
+
|
|
|
+ pushq %rax { Push garbage because we push 8 more bytes. }
|
|
|
+
|
|
|
+ { Provide the highest stack address to the user code (for stacks
|
|
|
+ which grow downwards). }
|
|
|
+ pushq %rsp
|
|
|
+
|
|
|
+ { Pass address of our own entry points to .fini and .init. }
|
|
|
+ movq $ini_dummy, %r8
|
|
|
+ movq $ini_dummy, %rcx
|
|
|
+
|
|
|
+ movq $main_stub, %rdi
|
|
|
+
|
|
|
+ { Call the user's main function, and exit with its value.
|
|
|
+ But let the libc call main. }
|
|
|
+ call libc_start_main
|
|
|
+
|
|
|
+ hlt { Crash if somehow `exit' does return. }
|
|
|
+
|
|
|
+ { We need this stuff to make gdb behave itself, otherwise
|
|
|
+ gdb will chokes with SIGILL when trying to debug apps.
|
|
|
+ }
|
|
|
+ .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
|
|
|
+ end;
|
|
|
+
|
|
|
+
|
|
|
+procedure _FPC_libc_haltproc; assembler; nostackframe; public name '_haltproc';
|
|
|
+ asm
|
|
|
+ movzwq operatingsystem_result,%rax { load and save exitcode }
|
|
|
+
|
|
|
+ movq ___fpc_ret,%rdx { return to libc }
|
|
|
+ movq ___fpc_ret_rbp,%rbp
|
|
|
+ pushq %rdx
|
|
|
+ ret
|
|
|
+ end;
|
florian