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321 theseven 1
/***************************************************************************
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 *             __________               __   ___.
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 *   Open      \______   \ ____   ____ |  | _\_ |__   _______  ___
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 *   Source     |       _//  _ \_/ ___\|  |/ /| __ \ /  _ \  \/  /
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 *   Jukebox    |    |   (  <_> )  \___|    < | \_\ (  <_> > <  <
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 *   Firmware   |____|_  /\____/ \___  >__|_ \|___  /\____/__/\_ \
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 *                     \/            \/     \/    \/            \/
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 * $Id$
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 *
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 * Copyright (C) 2006 by Thom Johansen
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 *
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 * This program is free software; you can redistribute it and/or
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 * modify it under the terms of the GNU General Public License
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 * as published by the Free Software Foundation; either version 2
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 * of the License, or (at your option) any later version.
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 *
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 * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
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 * KIND, either express or implied.
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 *
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 ****************************************************************************/
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286 theseven 22
#define ASM_FILE
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#include "global.h"
321 theseven 24
 
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/* ARMv4T doesn't switch the T bit when popping pc directly, we must use BX */
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.macro ldmpc cond="", order="ia", regs
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#if ARM_ARCH == 4 && defined(USE_THUMB)
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    ldm\cond\order sp!, { \regs, lr }
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    bx\cond lr
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#else
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    ldm\cond\order sp!, { \regs, pc }
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#endif
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.endm
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.macro ldrpc cond=""
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#if ARM_ARCH == 4 && defined(USE_THUMB)
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    ldr\cond lr, [sp], #4
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    bx\cond  lr
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#else
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    ldr\cond pc, [sp], #4
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#endif
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.endm
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    .section    .icode,"ax",%progbits
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    .align      2
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/*  The following code is based on code found in Linux kernel version 2.6.15.3
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 *  linux/arch/arm/lib/memset.S
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 *
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 *  Copyright (C) 1995-2000 Russell King
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 */
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/* This code will align a pointer for memset, if needed */
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1:      cmp     r2, #4                  @ 1 do we have enough
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        blt     5f                      @ 1 bytes to align with?
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        cmp     r3, #2                  @ 1
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        strgtb  r1, [r0, #-1]!          @ 1
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        strgeb  r1, [r0, #-1]!          @ 1
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        strb    r1, [r0, #-1]!          @ 1
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        sub     r2, r2, r3              @ 1 r2 = r2 - r3
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        b 2f
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        .global     memset
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        .type       memset,%function
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memset:
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        add     r0, r0, r2              @ we'll write backwards in memory
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        ands    r3, r0, #3              @ 1 unaligned?
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        bne     1b                      @ 1
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2:
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/*
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 * we know that the pointer in r0 is aligned to a word boundary.
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 */
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        orr     r1, r1, r1, lsl #8
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        orr     r1, r1, r1, lsl #16
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        mov     r3, r1
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        cmp     r2, #16
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        blt     5f
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/*
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 * We need an extra register for this loop - save the return address and
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 * use the LR
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 */
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        str     lr, [sp, #-4]!
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        mov     ip, r1
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        mov     lr, r1
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3:      subs    r2, r2, #64
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        stmgedb r0!, {r1, r3, ip, lr}   @ 64 bytes at a time.
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        stmgedb r0!, {r1, r3, ip, lr}
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        stmgedb r0!, {r1, r3, ip, lr}
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        stmgedb r0!, {r1, r3, ip, lr}
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        bgt     3b
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        ldrpc   cond=eq                 @ Now <64 bytes to go.
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/*
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 * No need to correct the count; we're only testing bits from now on
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 */
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        tst     r2, #32
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        stmnedb r0!, {r1, r3, ip, lr}
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        stmnedb r0!, {r1, r3, ip, lr}
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        tst     r2, #16
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        stmnedb r0!, {r1, r3, ip, lr}
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        ldr     lr, [sp], #4
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5:      tst     r2, #8
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        stmnedb r0!, {r1, r3}
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        tst     r2, #4
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        strne   r1, [r0, #-4]!
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/*
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 * When we get here, we've got less than 4 bytes to zero.  We
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 * may have an unaligned pointer as well.
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 */
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6:      tst     r2, #2
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        strneb  r1, [r0, #-1]!
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        strneb  r1, [r0, #-1]!
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        tst     r2, #1
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        strneb  r1, [r0, #-1]!
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        bx      lr
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.end:
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        .size   memset,.end-memset