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Diffstat (limited to 'sysdeps/cris/elf/start.S')
| -rw-r--r-- | sysdeps/cris/elf/start.S | 123 |
1 files changed, 123 insertions, 0 deletions
diff --git a/sysdeps/cris/elf/start.S b/sysdeps/cris/elf/start.S new file mode 100644 index 0000000000..f6336d2dab --- /dev/null +++ b/sysdeps/cris/elf/start.S @@ -0,0 +1,123 @@ +/* Startup code compliant to the ELF CRIS ABI (to-be-written). + Copyright (C) 2001 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> + +/* This is the canonical entry point, usually the first thing in the text + segment. When the entry point runs, most registers' values are + unspecified, except for: + + R10 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: + [SP] argc + [SP+4] argv[0] + ... + [SP+4*argc] NULL + [SP+4*(argc+1)] envp[0] + ... + NULL +*/ + + .syntax no_register_prefix + + .text + .globl _start +_start: + /* Clear the frame pointer, to mark the outermost frame. */ + moveq 0,r8 + + /* Move the shared library termination function to the right place + for __libc_main. */ + move.d r10,r9 + + /* Extract the arguments as encoded on the stack and set up the + arguments for `main': argc, argv. envp will be determined + later in __libc_start_main. */ + + /* Get the argument count. */ + move.d [sp],r11 + + /* Store the stack pointer as end of stack. We overwrite + the incoming argc. */ + move.d sp,[sp] + + /* The argument vector starts just after the argument count. */ + move.d sp,r12 + addq 4,r12 + + /* There are seven arguments to __libc_start_main: + r10: main - Address of it. + r11: argc + r12: argv + r13: init - Function to call. + + [sp]: fini - Function to register with atexit. + [sp+4]: rtld_fini - Another function to register with atexit. + [sp+8]: stack_end - Top of stack (actually same as argv). + + The last two are passed on stack. */ + + /* Store the fini function coming from the dynamic loader. */ + push r9 + + /* Get the addresses of our own entry points to `.fini' and + `.init'. */ + +#ifdef __PIC__ + /* If for some reason this program is compiled as PIC, set up R0. */ + move.d pc,r0 + sub.d .:GOTOFF,r0 + + move.d _init:PLTG,r13 + add.d r0,r13 + move.d _fini:PLTG,r9 + add.d r0,r9 + move.d main:PLTG,r10 + add.d r0,r10 +#else + move.d _init,r13 + move.d _fini,r9 + move.d main,r10 +#endif + push r9 + + /* Call the user's main function, and exit with its value. But + let the libc call main. */ + PLTCALL (__libc_start_main) + + /* Crash if somehow `exit' does return. We have at least 8192 + invalid addresses to choose from. */ + test.d [6502] + + /* Stop the unstoppable. */ +0: + ba 0b + nop + +/* 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 |