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Diffstat (limited to 'sysdeps/alpha/crti.S')
-rw-r--r-- | sysdeps/alpha/crti.S | 99 |
1 files changed, 99 insertions, 0 deletions
diff --git a/sysdeps/alpha/crti.S b/sysdeps/alpha/crti.S new file mode 100644 index 0000000000..f49d13648f --- /dev/null +++ b/sysdeps/alpha/crti.S @@ -0,0 +1,99 @@ +/* Special .init and .fini section support for Alpha. + Copyright (C) 2001-2014 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 Lesser General Public + License as published by the Free Software Foundation; either + version 2.1 of the License, or (at your option) any later version. + + In addition to the permissions in the GNU Lesser General Public + License, the Free Software Foundation gives you unlimited + permission to link the compiled version of this file with other + programs, and to distribute those programs without any restriction + coming from the use of this file. (The GNU Lesser General Public + License restrictions do apply in other respects; for example, they + cover modification of the file, and distribution when not linked + into another program.) + + Note that people who make modified versions of this file are not + obligated to grant this special exception for their modified + versions; it is their choice whether to do so. The GNU Lesser + General Public License gives permission to release a modified + version without this exception; this exception also makes it + possible to release a modified version which carries forward this + exception. + + 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 + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public + License along with the GNU C Library. If not, see + <http://www.gnu.org/licenses/>. */ + +/* crti.S puts a function prologue at the beginning of the .init and + .fini sections and defines global symbols for those addresses, so + they can be called as functions. The symbols _init and _fini are + magic and cause the linker to emit DT_INIT and DT_FINI. + + This differs from what would be generated for ordinary code in that + we save and restore the GP within the function. In order for linker + relaxation to work, the value in the GP register on exit from a function + must be valid for the function entry point. Normally, a function is + contained within one object file and this is not an issue, provided + that the function reloads the gp after making any function calls. + However, _init and _fini are constructed from pieces of many object + files, all of which may have different GP values. So we must reload + the GP value from crti.o in crtn.o. */ + +#include <libc-symbols.h> +#include <sysdep.h> + +#ifndef PREINIT_FUNCTION +# define PREINIT_FUNCTION __gmon_start__ +#endif + +#ifndef PREINIT_FUNCTION_WEAK +# define PREINIT_FUNCTION_WEAK 1 +#endif + +#if PREINIT_FUNCTION_WEAK + weak_extern (PREINIT_FUNCTION) +#else + .hidden PREINIT_FUNCTION +#endif + + .section .init, "ax", @progbits + .globl _init + .type _init, @function + .usepv _init, std +_init: + ldgp $29, 0($27) + subq $30, 16, $30 +#if PREINIT_FUNCTION_WEAK + lda $27, PREINIT_FUNCTION +#endif + stq $26, 0($30) + stq $29, 8($30) +#if PREINIT_FUNCTION_WEAK + beq $27, 1f + jsr $26, ($27), PREINIT_FUNCTION + ldq $29, 8($30) +1: +#else + bsr $26, PREINIT_FUNCTION !samegp +#endif + .p2align 3 + + .section .fini, "ax", @progbits + .globl _fini + .type _fini,@function + .usepv _fini,std +_fini: + ldgp $29, 0($27) + subq $30, 16, $30 + stq $26, 0($30) + stq $29, 8($30) + .p2align 3 |