1/* Startup code for programs linked with GNU libc. PowerPC64 version.
2 Copyright (C) 1998-2024 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#include <sysdep.h>
37
38/* We do not want .eh_frame info for crt1.o since crt1.o is linked
39 before crtbegin.o, the file defining __EH_FRAME_BEGIN__. */
40#undef cfi_startproc
41#define cfi_startproc
42#undef cfi_endproc
43#define cfi_endproc
44
45 /* These are the various addresses we require. */
46#ifdef PIC
47 .section ".data.rel.ro.local","aw"
48#else
49 .section ".rodata"
50#endif
51 .align 3
52L(start_addresses):
53 .quad 0 /* was _SDA_BASE_ but not in 64-bit ABI*/
54/* function descriptors so don't need JUMPTARGET */
55 .quad main
56 .quad 0 /* Used to be init. */
57 .quad 0 /* Used to be fini. */
58
59 ASM_SIZE_DIRECTIVE(L(start_addresses))
60
61 .section ".toc","aw"
62.L01:
63 .tc L(start_addresses)[TC],L(start_addresses)
64 .section ".text"
65ENTRY (_start)
66 /* Save the stack pointer, in case we're statically linked under Linux. */
67 mr r9,r1
68 /* Set up an initial stack frame, and clear the LR. */
69 clrrdi r1,r1,4
70 li r0,0
71 stdu r1,-128(r1)
72 mtlr r0
73 std r0,0(r1)
74
75 /* put the address of start_addresses in r8... **
76** PPC64 ABI uses R13 for thread local, so we leave it alone */
77 addis r8,r2,.L01@toc@ha
78 ld r8,.L01@toc@l(r8)
79
80 /* and continue in libc-start, in glibc. */
81 b JUMPTARGET(__libc_start_main)
82/* Older versions of ld need this nop to recognize that it's OK to call via a
83 TOC adjusting stub. */
84 nop
85
86END(_start)
87
88/* Define a symbol for the first piece of initialized data. */
89 .section ".data"
90 .globl __data_start
91__data_start:
92 .long 0
93weak_alias (__data_start, data_start)
94

source code of glibc/sysdeps/powerpc/powerpc64/start.S