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Diffstat (limited to 'firmware/asm/arm/memset16.S')
-rw-r--r-- | firmware/asm/arm/memset16.S | 82 |
1 files changed, 82 insertions, 0 deletions
diff --git a/firmware/asm/arm/memset16.S b/firmware/asm/arm/memset16.S new file mode 100644 index 0000000000..5c787b1bed --- /dev/null +++ b/firmware/asm/arm/memset16.S | |||
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1 | /*************************************************************************** | ||
2 | * __________ __ ___. | ||
3 | * Open \______ \ ____ ____ | | _\_ |__ _______ ___ | ||
4 | * Source | _// _ \_/ ___\| |/ /| __ \ / _ \ \/ / | ||
5 | * Jukebox | | ( <_> ) \___| < | \_\ ( <_> > < < | ||
6 | * Firmware |____|_ /\____/ \___ >__|_ \|___ /\____/__/\_ \ | ||
7 | * \/ \/ \/ \/ \/ | ||
8 | * $Id$ | ||
9 | * | ||
10 | * Copyright (C) 2006 by Thom Johansen | ||
11 | * | ||
12 | * This program is free software; you can redistribute it and/or | ||
13 | * modify it under the terms of the GNU General Public License | ||
14 | * as published by the Free Software Foundation; either version 2 | ||
15 | * of the License, or (at your option) any later version. | ||
16 | * | ||
17 | * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY | ||
18 | * KIND, either express or implied. | ||
19 | * | ||
20 | ****************************************************************************/ | ||
21 | #include "config.h" | ||
22 | |||
23 | .section .icode,"ax",%progbits | ||
24 | |||
25 | .align 2 | ||
26 | |||
27 | /* The following code is based on code from the Linux kernel version 2.6.15.3, | ||
28 | * linux/arch/arm/lib/memset.S | ||
29 | * | ||
30 | * Copyright (C) 1995-2000 Russell King | ||
31 | */ | ||
32 | |||
33 | .global memset16 | ||
34 | .type memset16,%function | ||
35 | memset16: | ||
36 | tst r0, #2 @ unaligned? | ||
37 | cmpne r2, #0 | ||
38 | strneh r1, [r0], #2 @ store one halfword to align | ||
39 | subne r2, r2, #1 | ||
40 | |||
41 | /* | ||
42 | * we know that the pointer in r0 is aligned to a word boundary. | ||
43 | */ | ||
44 | orr r1, r1, r1, lsl #16 | ||
45 | mov r3, r1 | ||
46 | cmp r2, #8 | ||
47 | blt 4f | ||
48 | /* | ||
49 | * We need an extra register for this loop - save the return address and | ||
50 | * use the LR | ||
51 | */ | ||
52 | str lr, [sp, #-4]! | ||
53 | mov ip, r1 | ||
54 | mov lr, r1 | ||
55 | |||
56 | 2: subs r2, r2, #32 | ||
57 | stmgeia r0!, {r1, r3, ip, lr} @ 64 bytes at a time. | ||
58 | stmgeia r0!, {r1, r3, ip, lr} | ||
59 | stmgeia r0!, {r1, r3, ip, lr} | ||
60 | stmgeia r0!, {r1, r3, ip, lr} | ||
61 | bgt 2b | ||
62 | ldrpc cond=eq @ Now <64 bytes to go. | ||
63 | /* | ||
64 | * No need to correct the count; we're only testing bits from now on | ||
65 | */ | ||
66 | tst r2, #16 | ||
67 | stmneia r0!, {r1, r3, ip, lr} | ||
68 | stmneia r0!, {r1, r3, ip, lr} | ||
69 | tst r2, #8 | ||
70 | stmneia r0!, {r1, r3, ip, lr} | ||
71 | ldr lr, [sp], #4 | ||
72 | |||
73 | 4: tst r2, #4 | ||
74 | stmneia r0!, {r1, r3} | ||
75 | tst r2, #2 | ||
76 | strne r1, [r0], #4 | ||
77 | |||
78 | tst r2, #1 | ||
79 | strneh r1, [r0], #2 | ||
80 | bx lr | ||
81 | .end: | ||
82 | .size memset16,.end-memset16 | ||