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- /***************************************************************************
- * Copyright (C) 2010 by Spencer Oliver *
- * spen@spen-soft.co.uk *
- * *
- * 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 program is distributed in the hope that it will be useful, *
- * but WITHOUT ANY WARRANTY; without even the implied warranty of *
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the *
- * GNU General Public License for more details. *
- * *
- * You should have received a copy of the GNU General Public License *
- * along with this program; if not, write to the *
- * Free Software Foundation, Inc., *
- * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. *
- ***************************************************************************/
-
- /*
- parameters:
- r0 - address in - crc out
- r1 - char count
- */
-
- .text
- .syntax unified
- .cpu cortex-m0
- .thumb
- .thumb_func
-
- .align 2
-
- _start:
- main:
- mov r2, r0
- movs r0, #0
- mvns r0, r0
- ldr r6, CRC32XOR
- mov r3, r1
- movs r4, #0
- b ncomp
- nbyte:
- ldrb r1, [r2, r4]
- lsls r1, r1, #24
- eors r0, r0, r1
- movs r5, #0
- loop:
- cmp r0, #0
- bge notset
- lsls r0, r0, #1
- eors r0, r0, r6
- b cont
- notset:
- lsls r0, r0, #1
- cont:
- adds r5, r5, #1
- cmp r5, #8
- bne loop
- adds r4, r4, #1
- ncomp:
- cmp r4, r3
- bne nbyte
- bkpt #0
-
- .align 2
-
- CRC32XOR: .word 0x04c11db7
-
- .end
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