1/* Startup code compliant to the ELF LoongArch ABI.
 2   Copyright (C) 2022-2025 Free Software Foundation, Inc.
 3   This file is part of the GNU C Library.
 4
 5   The GNU C Library is free software; you can redistribute it and/or
 6   modify it under the terms of the GNU Lesser General Public
 7   License as published by the Free Software Foundation; either
 8   version 2.1 of the License, or (at your option) any later version.
 9
10   In addition to the permissions in the GNU Lesser General Public
11   License, the Free Software Foundation gives you unlimited
12   permission to link the compiled version of this file with other
13   programs, and to distribute those programs without any restriction
14   coming from the use of this file. (The GNU Lesser General Public
15   License restrictions do apply in other respects; for example, they
16   cover modification of the file, and distribution when not linked
17   into another program.)
18
19   Note that people who make modified versions of this file are not
20   obligated to grant this special exception for their modified
21   versions; it is their choice whether to do so. The GNU Lesser
22   General Public License gives permission to release a modified
23   version without this exception; this exception also makes it
24   possible to release a modified version which carries forward this
25   exception.
26
27   The GNU C Library is distributed in the hope that it will be useful,
28   but WITHOUT ANY WARRANTY; without even the implied warranty of
29   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
30   Lesser General Public License for more details.
31
32   You should have received a copy of the GNU Lesser General Public
33   License along with the GNU C Library; if not, see
34   <https://www.gnu.org/licenses/>.  */
35
36#define __ASSEMBLY__ 1
37#include <entry.h>
38#include <sys/asm.h>
39
40/* The entry point's job is to call __libc_start_main.  Per the ABI,
41   a0 contains the address of a function to be passed to atexit.
42   __libc_start_main wants this in a5.  */
43
44/*
45int
46__libc_start_main (int (*main) (int, char **, char **),
47		   int argc,
48		   char **argv,
49		   __typeof (main) init,
50		   void (*fini) (void),
51		   void (*rtld_fini) (void),
52		   void *stack_end);
53 */
54
55ENTRY (ENTRY_POINT)
56
57/* Terminate call stack by noting ra is undefined.  Use a dummy
58   .cfi_label to force starting the FDE.  */
59	.cfi_label .Ldummy
60	cfi_undefined (1)
61	or		a5, a0, zero /* rtld_fini */
62
63	la.pcrel	a0, t0, main
64	REG_L		a1, sp, 0
65	ADDI		a2, sp, SZREG
66
67	/* Adjust $sp for 16-aligned */
68	BSTRINS		sp, zero, 3, 0
69
70	move		a3, zero /* used to be init */
71	move		a4, zero /* used to be fini */
72	or		a6, sp, zero /* stack_end */
73
74	la.pcrel	ra, t0, __libc_start_main
75	jirl		ra, ra, 0
76
77	la.pcrel	ra, t0, abort
78	jirl		ra, ra, 0
79END (ENTRY_POINT)