tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
1/* SPDX-License-Identifier: GPL-2.0 */
2#include "common.h"
3
4 .data
5 .balign 8
6success_message:
7 .ascii "success: switch_endian_test\n\0"
8
9 .balign 8
10failure_message:
11 .ascii "failure: switch_endian_test\n\0"
12
13 .section ".toc"
14 .balign 8
15pattern:
16 .8byte 0x5555AAAA5555AAAA
17
18 .text
19FUNC_START(_start)
20 /* Load the pattern */
21 ld r15, pattern@TOC(%r2)
22
23 /* Setup CR, only CR2-CR4 are maintained */
24 lis r3, 0x00FF
25 ori r3, r3, 0xF000
26 mtcr r3
27
28 /* Load the pattern slightly modified into the registers */
29 mr r3, r15
30 addi r4, r15, 4
31
32 addi r5, r15, 32
33 mtlr r5
34
35 addi r5, r15, 5
36 addi r6, r15, 6
37 addi r7, r15, 7
38 addi r8, r15, 8
39
40 /* r9 - r12 are clobbered */
41
42 addi r13, r15, 13
43 addi r14, r15, 14
44
45 /* Skip r15 we're using it */
46
47 addi r16, r15, 16
48 addi r17, r15, 17
49 addi r18, r15, 18
50 addi r19, r15, 19
51 addi r20, r15, 20
52 addi r21, r15, 21
53 addi r22, r15, 22
54 addi r23, r15, 23
55 addi r24, r15, 24
56 addi r25, r15, 25
57 addi r26, r15, 26
58 addi r27, r15, 27
59 addi r28, r15, 28
60 addi r29, r15, 29
61 addi r30, r15, 30
62 addi r31, r15, 31
63
64 /*
65 * Call the syscall to switch endian.
66 * It clobbers r9-r12, XER, CTR and CR0-1,5-7.
67 */
68 li r0, __NR_switch_endian
69 sc
70
71 tdi 0, 0, 0x48 // b +8 if the endian was switched
72 b .Lfail // exit if endian didn't switch
73
74#include "check-reversed.S"
75
76 /* Flip back, r0 already has the switch syscall number */
77 .long 0x02000044 /* sc */
78
79#include "check.S"
80
81 ld r4, success_message@got(%r2)
82 li r5, 28 // strlen(success_message)
83 li r14, 0 // exit status
84.Lout:
85 li r0, __NR_write
86 li r3, 1 /* stdout */
87 sc
88 li r0, __NR_exit
89 mr r3, r14
90 sc
91 b .
92
93.Lfail:
94 ld r4, failure_message@got(%r2)
95 li r5, 28 // strlen(failure_message)
96 li r14, 1
97 b .Lout