/*************************************************************************** * 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., * * 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. * ***************************************************************************/ /* r0 - address in - crc out r1 - char count */ .text .arm _start: main: mov r2, r0 mov r0, #0xffffffff /* crc */ mov r3, r1 mov r4, #0 b ncomp nbyte: ldrb r1, [r2, r4] ldr r7, CRC32XOR eor r0, r0, r1, asl #24 mov r5, #0 loop: cmp r0, #0 mov r6, r0, asl #1 add r5, r5, #1 mov r0, r6 eorlt r0, r6, r7 cmp r5, #8 bne loop add r4, r4, #1 ncomp: cmp r4, r3 bne nbyte end: bkpt #0 CRC32XOR: .word 0x04c11db7 .end