/*************************************************************************** * __________ __ ___. * Open \______ \ ____ ____ | | _\_ |__ _______ ___ * Source | _// _ \_/ ___\| |/ /| __ \ / _ \ \/ / * Jukebox | | ( <_> ) \___| < | \_\ ( <_> > < < * Firmware |____|_ /\____/ \___ >__|_ \|___ /\____/__/\_ \ * \/ \/ \/ \/ \/ * $Id$ * * Copyright (C) 2006 by Thom Johansen * * This program is free software; you can redistribute it and/or * modify it under the terms of the GNU General Public License * as published by the Free Software Foundation; either version 2 * of the License, or (at your option) any later version. * * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY * KIND, either express or implied. * ****************************************************************************/ #include "config.h" .section .icode,"ax",%progbits .align 2 /* The following code is based on code found in Linux kernel version 2.6.15.3 * linux/arch/arm/lib/memset.S * * Copyright (C) 1995-2000 Russell King */ /* This code will align a pointer for memset, if needed */ 1: cmp r2, #4 @ 1 do we have enough blt 5f @ 1 bytes to align with? cmp r3, #2 @ 1 strgtb r1, [r0, #-1]! @ 1 strgeb r1, [r0, #-1]! @ 1 strb r1, [r0, #-1]! @ 1 sub r2, r2, r3 @ 1 r2 = r2 - r3 b 2f .global memset .type memset,%function memset: add r0, r0, r2 @ we'll write backwards in memory ands r3, r0, #3 @ 1 unaligned? bne 1b @ 1 2: /* * we know that the pointer in r0 is aligned to a word boundary. */ orr r1, r1, r1, lsl #8 orr r1, r1, r1, lsl #16 mov r3, r1 cmp r2, #16 blt 5f /* * We need an extra register for this loop - save the return address and * use the LR */ str lr, [sp, #-4]! mov ip, r1 mov lr, r1 3: subs r2, r2, #64 stmgedb r0!, {r1, r3, ip, lr} @ 64 bytes at a time. stmgedb r0!, {r1, r3, ip, lr} stmgedb r0!, {r1, r3, ip, lr} stmgedb r0!, {r1, r3, ip, lr} bgt 3b ldrpc cond=eq @ Now <64 bytes to go. /* * No need to correct the count; we're only testing bits from now on */ tst r2, #32 stmnedb r0!, {r1, r3, ip, lr} stmnedb r0!, {r1, r3, ip, lr} tst r2, #16 stmnedb r0!, {r1, r3, ip, lr} ldr lr, [sp], #4 5: tst r2, #8 stmnedb r0!, {r1, r3} tst r2, #4 strne r1, [r0, #-4]! /* * When we get here, we've got less than 4 bytes to zero. We * may have an unaligned pointer as well. */ 6: tst r2, #2 strneb r1, [r0, #-1]! strneb r1, [r0, #-1]! tst r2, #1 strneb r1, [r0, #-1]! bx lr .end: .size memset,.end-memset