74 lines
2.2 KiB
ArmAsm
74 lines
2.2 KiB
ArmAsm
/***************************************************************************
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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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* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. *
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***************************************************************************/
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/*
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parameters:
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r0 - pointer to struct { uint32_t size_in_result_out, uint32_t addr }
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r1 - value to check
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*/
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.text
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.syntax unified
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.cpu cortex-m0
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.thumb
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.thumb_func
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.align 2
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BLOCK_SIZE_RESULT = 0
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BLOCK_ADDRESS = 4
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SIZEOF_STRUCT_BLOCK = 8
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start:
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block_loop:
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ldr r2, [r0, #BLOCK_SIZE_RESULT] /* get size */
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tst r2, r2
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beq done
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ldr r3, [r0, #BLOCK_ADDRESS] /* get address */
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word_loop:
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ldr r4, [r3] /* read word */
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adds r3, #4
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cmp r4, r1
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bne not_erased
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subs r2, #1
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bne word_loop
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movs r4, #1 /* block is erased */
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save_result:
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str r4, [r0, #BLOCK_SIZE_RESULT]
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adds r0, #SIZEOF_STRUCT_BLOCK
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b block_loop
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not_erased:
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movs r4, #0
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b save_result
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/* Avoid padding at .text segment end. Otherwise exit point check fails. */
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.skip ( . - start + 2) & 2, 0
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done:
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bkpt #0
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.end
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