diff options
Diffstat (limited to 'sysdeps/or1k/dl-start.S')
| -rw-r--r-- | sysdeps/or1k/dl-start.S | 98 |
1 files changed, 98 insertions, 0 deletions
diff --git a/sysdeps/or1k/dl-start.S b/sysdeps/or1k/dl-start.S new file mode 100644 index 0000000000..e2c990c0e2 --- /dev/null +++ b/sysdeps/or1k/dl-start.S @@ -0,0 +1,98 @@ +/* Machine-dependent ELF startup code. OpenRISC version. + Copyright (C) 2022 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 + <https://www.gnu.org/licenses/>. */ + +#include <sysdep.h> + +/* Initial entry point code for the dynamic linker. + The function _dl_start is the real entry point; + it's return value is the user program's entry point. */ +ENTRY (_start) + /* Count arguments in r11 */ + l.ori r3, r1, 0 + l.movhi r11, 0 +1: + l.addi r3, r3, 4 + l.lwz r12, 0(r3) + l.sfnei r12, 0 + l.addi r11, r11, 1 + l.bf 1b + l.nop + l.addi r11, r11, -1 + /* store argument counter to stack. */ + l.sw 0(r1), r11 + + /* Load the PIC register. */ + l.jal 0x8 + l.movhi r16, gotpchi(_GLOBAL_OFFSET_TABLE_-4) + l.ori r16, r16, gotpclo(_GLOBAL_OFFSET_TABLE_+0) + l.add r16, r16, r9 + + l.ori r3, r1, 0 + + l.jal _dl_start + l.nop + /* Save user entry in a call saved reg. */ + l.ori r22, r11, 0 + /* Fall through to _dl_start_user. */ + +_dl_start_user: + /* Set up for _dl_init. */ + + /* Load _rtld_local (a.k.a _dl_loaded). */ + l.lwz r12, got(_rtld_local)(r16) + l.lwz r3, 0(r12) + + /* Load argc */ + l.lwz r18, got(_dl_argc)(r16) + l.lwz r4, 0(r18) + + /* Load argv */ + l.lwz r20, got(_dl_argv)(r16) + l.lwz r5, 0(r20) + + /* Load envp = &argv[argc + 1]. */ + l.slli r6, r4, 2 + l.addi r6, r6, 4 + l.add r6, r6, r5 + + l.jal plt(_dl_init) + l.nop + + /* Now set up for user entry. + The already defined ABI loads argc and argv from the stack. + + argc = 0(r1) + argv = r1 + 4 + */ + + /* Load SP as argv - 4. */ + l.lwz r3, 0(r20) + l.addi r1, r3, -4 + + /* Save argc. */ + l.lwz r3, 0(r18) + l.sw 0(r1), r3 + + /* Pass _dl_fini function address to _start. + Next start.S will then pass this as rtld_fini to __libc_start_main. */ + l.lwz r3, got(_dl_fini)(r16) + + l.jr r22 + l.nop + +END (_start) |