| Linus Nielsen Feltzing | 5a0cb68 | 2006-07-25 11:16:03 +0000 | [diff] [blame] | 1 | /*************************************************************************** |
| 2 | * __________ __ ___. |
| 3 | * Open \______ \ ____ ____ | | _\_ |__ _______ ___ |
| 4 | * Source | _// _ \_/ ___\| |/ /| __ \ / _ \ \/ / |
| 5 | * Jukebox | | ( <_> ) \___| < | \_\ ( <_> > < < |
| 6 | * Firmware |____|_ /\____/ \___ >__|_ \|___ /\____/__/\_ \ |
| 7 | * \/ \/ \/ \/ \/ |
| 8 | * $Id$ |
| 9 | * |
| Linus Nielsen Feltzing | 8218d47 | 2006-07-25 11:37:54 +0000 | [diff] [blame] | 10 | * Copyright (C) 2006 by Thom Johansen |
| Linus Nielsen Feltzing | 5a0cb68 | 2006-07-25 11:16:03 +0000 | [diff] [blame] | 11 | * |
| Daniel Stenberg | 2acc0ac | 2008-06-28 18:10:04 +0000 | [diff] [blame^] | 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. |
| Linus Nielsen Feltzing | 5a0cb68 | 2006-07-25 11:16:03 +0000 | [diff] [blame] | 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 found in 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 | /* This code will align a pointer for memset, if needed */ |
| 34 | 1: cmp r2, #4 @ 1 do we have enough |
| 35 | blt 5f @ 1 bytes to align with? |
| 36 | cmp r3, #2 @ 1 |
| 37 | strgtb r1, [r0, #-1]! @ 1 |
| 38 | strgeb r1, [r0, #-1]! @ 1 |
| 39 | strb r1, [r0, #-1]! @ 1 |
| 40 | sub r2, r2, r3 @ 1 r2 = r2 - r3 |
| 41 | b 2f |
| 42 | |
| 43 | .global memset |
| 44 | .type memset,%function |
| 45 | memset: |
| 46 | add r0, r0, r2 @ we'll write backwards in memory |
| 47 | ands r3, r0, #3 @ 1 unaligned? |
| 48 | bne 1b @ 1 |
| 49 | 2: |
| 50 | /* |
| 51 | * we know that the pointer in r0 is aligned to a word boundary. |
| 52 | */ |
| 53 | orr r1, r1, r1, lsl #8 |
| 54 | orr r1, r1, r1, lsl #16 |
| 55 | mov r3, r1 |
| 56 | cmp r2, #16 |
| 57 | blt 5f |
| 58 | /* |
| 59 | * We need an extra register for this loop - save the return address and |
| 60 | * use the LR |
| 61 | */ |
| 62 | str lr, [sp, #-4]! |
| 63 | mov ip, r1 |
| 64 | mov lr, r1 |
| 65 | |
| 66 | 3: subs r2, r2, #64 |
| 67 | stmgedb r0!, {r1, r3, ip, lr} @ 64 bytes at a time. |
| 68 | stmgedb r0!, {r1, r3, ip, lr} |
| 69 | stmgedb r0!, {r1, r3, ip, lr} |
| 70 | stmgedb r0!, {r1, r3, ip, lr} |
| 71 | bgt 3b |
| 72 | ldmeqfd sp!, {pc} @ Now <64 bytes to go. |
| 73 | /* |
| 74 | * No need to correct the count; we're only testing bits from now on |
| 75 | */ |
| 76 | tst r2, #32 |
| 77 | stmnedb r0!, {r1, r3, ip, lr} |
| 78 | stmnedb r0!, {r1, r3, ip, lr} |
| 79 | tst r2, #16 |
| 80 | stmnedb r0!, {r1, r3, ip, lr} |
| 81 | ldr lr, [sp], #4 |
| 82 | |
| 83 | 5: tst r2, #8 |
| 84 | stmnedb r0!, {r1, r3} |
| 85 | tst r2, #4 |
| 86 | strne r1, [r0, #-4]! |
| 87 | /* |
| 88 | * When we get here, we've got less than 4 bytes to zero. We |
| 89 | * may have an unaligned pointer as well. |
| 90 | */ |
| 91 | 6: tst r2, #2 |
| 92 | strneb r1, [r0, #-1]! |
| 93 | strneb r1, [r0, #-1]! |
| 94 | tst r2, #1 |
| 95 | strneb r1, [r0, #-1]! |
| Thom Johansen | 7d7b704 | 2006-09-07 00:35:07 +0000 | [diff] [blame] | 96 | bx lr |
| 97 | .end: |
| Linus Nielsen Feltzing | 5a0cb68 | 2006-07-25 11:16:03 +0000 | [diff] [blame] | 98 | .size memset,.end-memset |