diff options
Diffstat (limited to 'sysdeps/arm/elf')
| -rw-r--r-- | sysdeps/arm/elf/setjmp.S | 76 | ||||
| -rw-r--r-- | sysdeps/arm/elf/start.S | 109 |
2 files changed, 185 insertions, 0 deletions
diff --git a/sysdeps/arm/elf/setjmp.S b/sysdeps/arm/elf/setjmp.S new file mode 100644 index 0000000000..51572ca515 --- /dev/null +++ b/sysdeps/arm/elf/setjmp.S @@ -0,0 +1,76 @@ +/* setjmp for arm, ELF version. + Copyright (C) 1995, 1996, 1997, 1998 Free Software Foundation, Inc. + This file is part of the GNU C Library. + + The GNU C Library is free software; you can redistribute it and/or + modify it under the terms of the GNU Library General Public License as + published by the Free Software Foundation; either version 2 of the + License, or (at your option) any later version. + + The GNU C Library 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 + Library General Public License for more details. + + You should have received a copy of the GNU Library General Public + License along with the GNU C Library; see the file COPYING.LIB. If not, + write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330, + Boston, MA 02111-1307, USA. */ + +#include <sysdep.h> +#define _ASM +#define _SETJMP_H +#include <bits/setjmp.h> + + /* We include the BSD entry points here as well but we make + them weak. */ +ENTRY (setjmp) + .weak C_SYMBOL_NAME (setjmp) + @ call comes here with + @ lr = return pc + @ r0 = &jump_buf + + @ add a second argument into the fray + mov r1, #1 + @ call the common code + b __sigsetjmp(PLT) +END (setjmp) + + /* Binary compatibility entry point. */ +ENTRY (_setjmp) + .weak C_SYMBOL_NAME (_setjmp) +ENTRY (__setjmp) + @ call comes here with + @ lr = return pc + @ r0 = &jump_buf + + @ add a second argument into the fray + mov r1, #1 + @ fall through to the common code.... + +ENTRY (__sigsetjmp) + @ save the registers into the jmp_buf.... + stmia r0, {r1-r6, sl, fp, sp, lr} + + /* Make a tail call to __sigjmp_save; it takes the same args. */ +#ifdef PIC + /* We cannot use the PLT, because it requires that sl==r10 be set, but + we can't save and restore our caller's value. Instead, we do an + indirect jump through the GOT, using for the temporary register + ip, which is call-clobbered. */ + ldr ip, 1f + add ip, ip, pc +2: @ get the address of __sigjmp_save + ldr r1, 3f + ldr ip, [ip, r1] + @ restore r1 + ldr r1, [r0] + @ jump to *__sigjmp_save + mov pc, ip +1: .word _GLOBAL_OFFSET_TABLE_ - 2b - 4 +3: .word __sigjmp_save(GOT) + +#else + b __sigjmp_save +#endif +END (__sigsetjmp) diff --git a/sysdeps/arm/elf/start.S b/sysdeps/arm/elf/start.S new file mode 100644 index 0000000000..e0964a1e38 --- /dev/null +++ b/sysdeps/arm/elf/start.S @@ -0,0 +1,109 @@ +/* Startup code for ARM & ELF + Copyright (C) 1995, 1996, 1997, 1998 Free Software Foundation, Inc. + This file is part of the GNU C Library. + + The GNU C Library is free software; you can redistribute it and/or + modify it under the terms of the GNU Library General Public License as + published by the Free Software Foundation; either version 2 of the + License, or (at your option) any later version. + + The GNU C Library 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 + Library General Public License for more details. + + You should have received a copy of the GNU Library General Public + License along with the GNU C Library; see the file COPYING.LIB. If not, + write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330, + Boston, MA 02111-1307, USA. */ + +/* This is the canonical entry point, usually the first thing in the text + segment. + + Note that the code in the .init section has already been run. + This includes _init and _libc_init + + + At this entry point, most registers' values are unspecified, except for: + + r0 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. + + sp The stack contains the arguments and environment: + 0(%esp) argc + 4(%esp) argv[0] + ... + (4*argc)(%esp) NULL + (4*(argc+1))(%esp) envp[0] + ... + NULL +*/ + + .text + .globl _start +_start: + /* Clear the frame pointer. The Intel ABI suggests this be done, + to mark the outermost frame obviously. This seems like a + sensible thing to do */ + mov fp, #0 + + /* r0 contains the address of the shared library termination + function, which we will register with `atexit' to be called by + `exit'. I suspect that on some systems, and when statically + linked, this will not be set by anything to any function + pointer; hopefully it will be zero so we don't try to call + random pointers. */ + cmp r0,#0 + blne atexit(PLT) + + /* Do essential libc initialization. In statically linked + programs under the GNU Hurd, this is what sets up the + arguments on the stack for the code below. For dyn-link + programs, this has been run already, in the .init code. */ +#ifndef PIC + bl __libc_init_first + + /* Extract the arguments and environment as encoded on the stack + and set up the arguments for `main': argc, argv, envp. */ + ldr r0,[sp] + add r1,sp,#4 + add r2,r1,r0,lsl #2 + add r2,r2,#4 + /* save a copy of envp while we have it */ + ldr r3,L_environ + str r2,[r3] + + /* Call `_init', which is the entry point to our own `.init' + section; and register with `atexit' to have `exit' call + `_fini', which is the entry point to our own `.fini' section. */ + bl _init + ldr r0,L_fini + bl atexit + b L_pfini + +L_fini: .word _fini +L_environ: .word _environ +L_pfini: +#endif + /* rebuild the arg list for main() */ + ldr r0,[sp] + add r1,sp,#4 + add r2,r1,r0,lsl #2 + add r2,r2,#4 + + /* Call the user's main function, and exit with its value. */ + bl main + bl exit + /* should never get here....*/ + bl abort + + +/* 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 |