linux/tools/testing/selftests/powerpc/switch_endian/switch_endian_test.S

#include "common.h"

	.data
	.balign 8
message:
	.ascii "success: switch_endian_test\n\0"

	.section ".toc"
	.balign 8
pattern:
	.llong 0x5555AAAA5555AAAA

	.text
FUNC_START(_start)
	/* Load the pattern */
	ld	r15, pattern@TOC(%r2)

	/* Setup CR, only CR2-CR4 are maintained */
	lis	r3, 0x00FF
	ori	r3, r3, 0xF000
	mtcr	r3

	/* Load the pattern slightly modified into the registers */
	mr	r3, r15
	addi	r4, r15, 4

	addi	r5, r15, 32
	mtlr	r5

	addi	r5, r15, 5
	addi	r6, r15, 6
	addi	r7, r15, 7
	addi	r8, r15, 8

	/* r9 - r12 are clobbered */

	addi	r13, r15, 13
	addi	r14, r15, 14

	/* Skip r15 we're using it */

	addi	r16, r15, 16
	addi	r17, r15, 17
	addi	r18, r15, 18
	addi	r19, r15, 19
	addi	r20, r15, 20
	addi	r21, r15, 21
	addi	r22, r15, 22
	addi	r23, r15, 23
	addi	r24, r15, 24
	addi	r25, r15, 25
	addi	r26, r15, 26
	addi	r27, r15, 27
	addi	r28, r15, 28
	addi	r29, r15, 29
	addi	r30, r15, 30
	addi	r31, r15, 31

	/*
	 * Call the syscall to switch endian.
	 * It clobbers r9-r12, XER, CTR and CR0-1,5-7.
	 */
	li r0, __NR_switch_endian
	sc

#include "check-reversed.S"

	/* Flip back, r0 already has the switch syscall number */
	.long	0x02000044	/* sc */

#include "check.S"

	li	r0, __NR_write
	li	r3, 1	/* stdout */
	ld	r4, message@got(%r2)
	li	r5, 28	/* strlen(message3) */
	sc
	li      r0, __NR_exit
	li	r3, 0
	sc
	b       .
selftests/powerpc: Add a test of the switch_endian() syscall This adds a test of the switch_endian() syscall we added in the previous commit. We test it by calling the endian switch syscall, and then executing some code in the other endian to check everything went as expected. That code checks registers we expect to be maintained are. If the endian switch failed to happen that code sequence will be illegal and cause the test to abort. We then switch back to the original endian, do the same checks and finally write a success message and exit(0). Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> 2015-03-28 18:35:17 +08:00			`#include "common.h"`

			`.data`
			`.balign 8`
			`message:`
			`.ascii "success: switch_endian_test\n\0"`

			`.section ".toc"`
			`.balign 8`
			`pattern:`
			`.llong 0x5555AAAA5555AAAA`

			`.text`
			`FUNC_START(_start)`
			`/* Load the pattern */`
			`ld r15, pattern@TOC(%r2)`

			`/* Setup CR, only CR2-CR4 are maintained */`
			`lis r3, 0x00FF`
			`ori r3, r3, 0xF000`
			`mtcr r3`

			`/* Load the pattern slightly modified into the registers */`
			`mr r3, r15`
			`addi r4, r15, 4`

			`addi r5, r15, 32`
			`mtlr r5`

			`addi r5, r15, 5`
			`addi r6, r15, 6`
			`addi r7, r15, 7`
			`addi r8, r15, 8`

			`/* r9 - r12 are clobbered */`

			`addi r13, r15, 13`
			`addi r14, r15, 14`

			`/* Skip r15 we're using it */`

			`addi r16, r15, 16`
			`addi r17, r15, 17`
			`addi r18, r15, 18`
			`addi r19, r15, 19`
			`addi r20, r15, 20`
			`addi r21, r15, 21`
			`addi r22, r15, 22`
			`addi r23, r15, 23`
			`addi r24, r15, 24`
			`addi r25, r15, 25`
			`addi r26, r15, 26`
			`addi r27, r15, 27`
			`addi r28, r15, 28`
			`addi r29, r15, 29`
			`addi r30, r15, 30`
			`addi r31, r15, 31`

			`/*`
			`* Call the syscall to switch endian.`
			`* It clobbers r9-r12, XER, CTR and CR0-1,5-7.`
			`*/`
			`li r0, __NR_switch_endian`
			`sc`

			`#include "check-reversed.S"`

			`/* Flip back, r0 already has the switch syscall number */`
			`.long 0x02000044 /* sc */`

			`#include "check.S"`

			`li r0, __NR_write`
			`li r3, 1 /* stdout */`
			`ld r4, message@got(%r2)`
			`li r5, 28 /* strlen(message3) */`
			`sc`
			`li r0, __NR_exit`
			`li r3, 0`
			`sc`
			`b .`