55 lines
2.1 KiB
ArmAsm
55 lines
2.1 KiB
ArmAsm
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/***************************************************************************
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* Copyright (C) 2010 by Spencer Oliver *
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* spen@spen-soft.co.uk *
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* *
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* This program is free software; you can redistribute it and/or modify *
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* it under the terms of the GNU General Public License as published by *
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* the Free Software Foundation; either version 2 of the License, or *
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* (at your option) any later version. *
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* *
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* This program is distributed in the hope that it will be useful, *
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* but WITHOUT ANY WARRANTY; without even the implied warranty of *
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the *
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* GNU General Public License for more details. *
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* *
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* You should have received a copy of the GNU General Public License *
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* along with this program; if not, write to the *
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* Free Software Foundation, Inc., *
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* 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. *
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***************************************************************************/
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.text
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.arm
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.section .init
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/*
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r0 source address (in)
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r1 target address (in)
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r2 word count (in)
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r3 result (out)
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*/
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write:
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bic r4, r1, #3 /* word address */
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mov r3, #0x40 /* write command */
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strh r3, [r4, #0]
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ldrh r3, [r0], #2 /* read data */
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strh r3, [r1], #2 /* write data */
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mov r3, #0x70 /* status command */
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strh r3, [r4, #0]
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busy:
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ldrb r3, [r4, #0] /* status */
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tst r3, #0x80
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beq busy
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mov r5, #0x50 /* clear status command */
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strh r5, [r4, #0]
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mov r5, #0xFF /* read array */
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strh r5, [r4, #0]
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tst r3, #0x12
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bne exit
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subs r2, r2, #1 /* decremment word count */
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bne write
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exit:
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bkpt #0
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.end
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