xref: /linux/arch/x86/boot/copy.S (revision cc04a46f11ea046ed53e2c832ae29e4790f7e35f)
1/* ----------------------------------------------------------------------- *
2 *
3 *   Copyright (C) 1991, 1992 Linus Torvalds
4 *   Copyright 2007 rPath, Inc. - All Rights Reserved
5 *
6 *   This file is part of the Linux kernel, and is made available under
7 *   the terms of the GNU General Public License version 2.
8 *
9 * ----------------------------------------------------------------------- */
10
11#include <linux/linkage.h>
12
13/*
14 * Memory copy routines
15 */
16
17	.code16
18	.text
19
20GLOBAL(memcpy)
21	pushw	%si
22	pushw	%di
23	movw	%ax, %di
24	movw	%dx, %si
25	pushw	%cx
26	shrw	$2, %cx
27	rep; movsl
28	popw	%cx
29	andw	$3, %cx
30	rep; movsb
31	popw	%di
32	popw	%si
33	retl
34ENDPROC(memcpy)
35
36GLOBAL(memset)
37	pushw	%di
38	movw	%ax, %di
39	movzbl	%dl, %eax
40	imull	$0x01010101,%eax
41	pushw	%cx
42	shrw	$2, %cx
43	rep; stosl
44	popw	%cx
45	andw	$3, %cx
46	rep; stosb
47	popw	%di
48	retl
49ENDPROC(memset)
50
51GLOBAL(copy_from_fs)
52	pushw	%ds
53	pushw	%fs
54	popw	%ds
55	calll	memcpy
56	popw	%ds
57	retl
58ENDPROC(copy_from_fs)
59
60GLOBAL(copy_to_fs)
61	pushw	%es
62	pushw	%fs
63	popw	%es
64	calll	memcpy
65	popw	%es
66	retl
67ENDPROC(copy_to_fs)
68
69#if 0 /* Not currently used, but can be enabled as needed */
70GLOBAL(copy_from_gs)
71	pushw	%ds
72	pushw	%gs
73	popw	%ds
74	calll	memcpy
75	popw	%ds
76	retl
77ENDPROC(copy_from_gs)
78
79GLOBAL(copy_to_gs)
80	pushw	%es
81	pushw	%gs
82	popw	%es
83	calll	memcpy
84	popw	%es
85	retl
86ENDPROC(copy_to_gs)
87#endif
88