| /* Copyright (C) 1995-2016 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/>. */ |
| |
| /* 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 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 x1, [sp, #0] |
| add x2, sp, #8 |
| |
| /* Setup stack limit in argument register */ |
| mov x6, sp |
| |
| #ifdef SHARED |
| adrp x0, :got:main |
| ldr x0, [x0, #:got_lo12:main] |
| |
| adrp x3, :got:__libc_csu_init |
| ldr x3, [x3, #:got_lo12:__libc_csu_init] |
| |
| adrp x4, :got:__libc_csu_fini |
| ldr x4, [x4, #:got_lo12:__libc_csu_fini] |
| #else |
| /* Set up the other arguments in registers */ |
| ldr x0, =main |
| ldr x3, =__libc_csu_init |
| ldr x4, =__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 |