mirror of
https://sourceware.org/git/glibc.git
synced 2024-12-27 21:20:18 +00:00
2dd12baa04
Mark the ra register as undefined in _start, so that unwinding through main works correctly. Also, don't use a tail call so that ra points after the call to __libc_start_main, not after the previous call.
87 lines
3.1 KiB
ArmAsm
87 lines
3.1 KiB
ArmAsm
/* Startup code compliant to the ELF RISC-V ABI.
|
|
Copyright (C) 1995-2018 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/>. */
|
|
|
|
#define __ASSEMBLY__ 1
|
|
#include <entry.h>
|
|
#include <sysdep.h>
|
|
#include <sys/asm.h>
|
|
|
|
/* The entry point's job is to call __libc_start_main. Per the ABI,
|
|
a0 contains the address of a function to be passed to atexit.
|
|
__libc_start_main wants this in a5. */
|
|
|
|
ENTRY (ENTRY_POINT)
|
|
/* Terminate call stack by noting ra is undefined. Use a dummy
|
|
.cfi_label to force starting the FDE. */
|
|
.cfi_label .Ldummy
|
|
cfi_undefined (ra)
|
|
call .Lload_gp
|
|
mv a5, a0 /* rtld_fini. */
|
|
/* main may be in a shared library. */
|
|
la a0, main
|
|
REG_L a1, 0(sp) /* argc. */
|
|
addi a2, sp, SZREG /* argv. */
|
|
andi sp, sp, ALMASK /* Align stack. */
|
|
lla a3, __libc_csu_init
|
|
lla a4, __libc_csu_fini
|
|
mv a6, sp /* stack_end. */
|
|
|
|
call __libc_start_main@plt
|
|
ebreak
|
|
END (ENTRY_POINT)
|
|
|
|
/* Dynamic links need the global pointer to be initialized prior to calling
|
|
any shared library's initializers, so we use preinit_array to load it.
|
|
This doesn't cut it for static links, though, since the global pointer
|
|
needs to be initialized before calling __libc_start_main in that case.
|
|
So we redundantly initialize it at the beginning of _start. */
|
|
|
|
.Lload_gp:
|
|
.option push
|
|
.option norelax
|
|
lla gp, __global_pointer$
|
|
.option pop
|
|
ret
|
|
|
|
.section .preinit_array,"aw"
|
|
.dc.a .Lload_gp
|
|
|
|
/* Define a symbol for the first piece of initialized data. */
|
|
.data
|
|
.globl __data_start
|
|
__data_start:
|
|
.weak data_start
|
|
data_start = __data_start
|