1/* SPDX-License-Identifier: GPL-2.0-only */
2/* ----------------------------------------------------------------------- *
3 *
4 * Copyright (C) 1991, 1992 Linus Torvalds
5 * Copyright 2007 rPath, Inc. - All Rights Reserved
6 *
7 * ----------------------------------------------------------------------- */
8
9#include <linux/linkage.h>
10
11/*
12 * Memory copy routines
13 */
14
15 .code16
16 .text
17
18SYM_FUNC_START_NOALIGN(memcpy)
19 pushw %si
20 pushw %di
21 movw %ax, %di
22 movw %dx, %si
23 pushw %cx
24 shrw $2, %cx
25 rep; movsl
26 popw %cx
27 andw $3, %cx
28 rep; movsb
29 popw %di
30 popw %si
31 retl
32SYM_FUNC_END(memcpy)
33
34SYM_FUNC_START_NOALIGN(memset)
35 pushw %di
36 movw %ax, %di
37 movzbl %dl, %eax
38 imull $0x01010101,%eax
39 pushw %cx
40 shrw $2, %cx
41 rep; stosl
42 popw %cx
43 andw $3, %cx
44 rep; stosb
45 popw %di
46 retl
47SYM_FUNC_END(memset)
48
49SYM_FUNC_START_NOALIGN(copy_from_fs)
50 pushw %ds
51 pushw %fs
52 popw %ds
53 calll memcpy
54 popw %ds
55 retl
56SYM_FUNC_END(copy_from_fs)
57
58SYM_FUNC_START_NOALIGN(copy_to_fs)
59 pushw %es
60 pushw %fs
61 popw %es
62 calll memcpy
63 popw %es
64 retl
65SYM_FUNC_END(copy_to_fs)
66

source code of linux/arch/x86/boot/copy.S