1 | /* Special .init and .fini section support for Alpha. |
2 | Copyright (C) 2001-2022 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 | /* crti.S puts a function prologue at the beginning of the .init and |
37 | .fini sections and defines global symbols for those addresses, so |
38 | they can be called as functions. The symbols _init and _fini are |
39 | magic and cause the linker to emit DT_INIT and DT_FINI. |
40 | |
41 | This differs from what would be generated for ordinary code in that |
42 | we save and restore the GP within the function. In order for linker |
43 | relaxation to work, the value in the GP register on exit from a function |
44 | must be valid for the function entry point. Normally, a function is |
45 | contained within one object file and this is not an issue, provided |
46 | that the function reloads the gp after making any function calls. |
47 | However, _init and _fini are constructed from pieces of many object |
48 | files, all of which may have different GP values. So we must reload |
49 | the GP value from crti.o in crtn.o. */ |
50 | |
51 | #include <libc-symbols.h> |
52 | #include <sysdep.h> |
53 | |
54 | #ifndef PREINIT_FUNCTION |
55 | # define PREINIT_FUNCTION __gmon_start__ |
56 | #endif |
57 | |
58 | #ifndef PREINIT_FUNCTION_WEAK |
59 | # define PREINIT_FUNCTION_WEAK 1 |
60 | #endif |
61 | |
62 | #if PREINIT_FUNCTION_WEAK |
63 | weak_extern (PREINIT_FUNCTION) |
64 | #else |
65 | .hidden PREINIT_FUNCTION |
66 | #endif |
67 | |
68 | .section .init, "ax" , @progbits |
69 | .globl _init |
70 | .hidden _init |
71 | .type _init, @function |
72 | .usepv _init, std |
73 | _init: |
74 | ldgp $29, 0($27) |
75 | subq $30, 16, $30 |
76 | #if PREINIT_FUNCTION_WEAK |
77 | lda $27, PREINIT_FUNCTION |
78 | #endif |
79 | stq $26, 0($30) |
80 | stq $29, 8($30) |
81 | #if PREINIT_FUNCTION_WEAK |
82 | beq $27, 1f |
83 | jsr $26, ($27), PREINIT_FUNCTION |
84 | ldq $29, 8($30) |
85 | 1: |
86 | #else |
87 | bsr $26, PREINIT_FUNCTION !samegp |
88 | #endif |
89 | .p2align 3 |
90 | |
91 | .section .fini, "ax" , @progbits |
92 | .globl _fini |
93 | .hidden _fini |
94 | .type _fini,@function |
95 | .usepv _fini,std |
96 | _fini: |
97 | ldgp $29, 0($27) |
98 | subq $30, 16, $30 |
99 | stq $26, 0($30) |
100 | stq $29, 8($30) |
101 | .p2align 3 |
102 | |