Orange Pi5 kernel

^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  1) // SPDX-License-Identifier: GPL-2.0
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  2) // Copyright (C) 2005-2017 Andes Technology Corporation
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  3) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  4) #include <linux/linkage.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  5) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  6) 	.text
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  7) ENTRY(memset)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  8) 	move	$r5, $r0		! Return value
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  9) 	beqz	$r2, end_memset		! Exit when len = 0
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 10) 	srli	$p1, $r2, 2		! $p1 is how many words to copy
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 11) 	andi	$r2, $r2, 3		! How many bytes are less than a word
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 12) 	beqz	$p1, byte_set		! When n is less than a word
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 13) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 14) 	! set $r1 from ??????ab to abababab
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 15) 	andi	$r1, $r1, #0x00ff	! $r1 = 000000ab
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 16) 	slli	$p0, $r1, #8		! $p0 = 0000ab00
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 17) 	or	$r1, $r1, $p0		! $r1 = 0000abab
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 18) 	slli	$p0, $r1, #16		! $p0 = abab0000
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 19) 	or	$r1, $r1, $p0		! $r1 = abababab
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 20) word_set:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 21) 	addi	$p1, $p1, #-1		! How many words left to copy
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 22) 	smw.bim	$r1, [$r0], $r1		! Copy the word to det
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 23) 	bnez	$p1, word_set		! Still words to set, continue looping
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 24) 	beqz	$r2, end_memset		! No left byte to set
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 25) byte_set:				! Less than 4 bytes left to set
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 26) 	addi	$r2, $r2, #-1		! Decrease len by 1
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 27) 	sbi.bi	$r1, [$r0], #1		! Set data of the next byte to $r1
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 28) 	bnez	$r2, byte_set		! Still bytes left to set
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 29) end_memset:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 30) 	move	$r0, $r5
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 31) 	ret
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 32) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 33) ENDPROC(memset)