diff options
Diffstat (limited to 'REORG.TODO/sysdeps/aarch64/start.S')
| -rw-r--r-- | REORG.TODO/sysdeps/aarch64/start.S | 94 |
1 files changed, 94 insertions, 0 deletions
diff --git a/REORG.TODO/sysdeps/aarch64/start.S b/REORG.TODO/sysdeps/aarch64/start.S new file mode 100644 index 0000000000..df1c642c12 --- /dev/null +++ b/REORG.TODO/sysdeps/aarch64/start.S @@ -0,0 +1,94 @@ +/* Copyright (C) 1995-2017 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. + + 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/>. */ + +#include <sysdep.h> + +/* 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: + + x0/w0 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(sp) argc + 8(sp) argv[0] + ... + (8*argc)(sp) NULL + (8*(argc+1))(sp) envp[0] + ... + NULL + */ + + .text + .globl _start + .type _start,#function +_start: + /* Create an initial frame with 0 LR and FP */ + mov x29, #0 + mov x30, #0 + + /* Setup rtld_fini in argument register */ + mov x5, x0 + + /* Load argc and a pointer to argv */ + ldr PTR_REG (1), [sp, #0] + add x2, sp, #PTR_SIZE + + /* Setup stack limit in argument register */ + mov x6, sp + +#ifdef SHARED + adrp x0, :got:main + ldr PTR_REG (0), [x0, #:got_lo12:main] + + adrp x3, :got:__libc_csu_init + ldr PTR_REG (3), [x3, #:got_lo12:__libc_csu_init] + + adrp x4, :got:__libc_csu_fini + ldr PTR_REG (4), [x4, #:got_lo12:__libc_csu_fini] +#else + /* Set up the other arguments in registers */ + ldr PTR_REG (0), =main + ldr PTR_REG (3), =__libc_csu_init + ldr PTR_REG (4), =__libc_csu_fini +#endif + + /* __libc_start_main (main, argc, argv, init, fini, rtld_fini, + stack_end) */ + + /* Let the libc call main and exit with its return code. */ + bl __libc_start_main + + /* 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 |