1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
|
/* start, 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.
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
<https://www.gnu.org/licenses/>. */
/* This is the canonical entry point, usually the first thing in the text
segment.
sp The stack contains the arguments and environment:
0(sp) argc
4(sp) argv[0]
...
(4*argc)(sp) NULL
(4*(argc+1))(sp) envp[0]
...
NULL
*/
#define __ASSEMBLY__
#include <sysdep.h>
#include <entry.h>
ENTRY (ENTRY_POINT)
/* Setup Arguments to the __libc_start_main function. */
/* Take values for argc and argv off the stack.
These will be passed as arguments two and three to main
and thus go in registers r4 and r5, respectively. */
l.lwz r4, 0(r1)
l.addi r5, r1, 4
/* Pass in rtld_fini from dl-start.S. */
l.or r8, r3, r3
#ifdef PIC
/* Obtain a pointer to .got in r16 */
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
/* Pass in the the main symbol. */
l.lwz r3, got(main)(r16)
#else
/* Pass in the the main symbol. */
l.movhi r3, hi(main)
l.ori r3, r3, lo(main)
#endif
/* Used to be init and fini. */
l.movhi r6, 0x0
l.movhi r7, 0x0
/* Push stack limit onto the stack.
This provides the highest stack address to user code (as stack grows
downwards.
This is the seventh argument to __libc_start_main and thus needs to
be passed on the stack. */
l.sw -4(r1), r1
/* Adjust stack to account for a total of 7 args (i.e. the last one is
on the stack. */
l.addi r1, r1, -4
/* Clear the frame pointer and link register since this is the
outermost frame. */
l.movhi r2, 0x0
l.movhi r9, 0x0
/* Let the libc call main and exit with its return code. */
#ifdef PIC
l.j plt(__libc_start_main)
#else
l.j __libc_start_main
#endif
l.nop
END (ENTRY_POINT)
/* Define a symbol for the first piece of initialized data. */
.data
.globl __data_start
__data_start:
.long 0
.weak data_start
data_start = __data_start
|
