1 files changed, 72 insertions, 0 deletions
diff --git a/contrib/loaders/checksum/mips32.s b/contrib/loaders/checksum/mips32.s
new file mode 100644
index 00000000..f8f08a23
--- /dev/null
+++ b/contrib/loaders/checksum/mips32.s
@@ -0,0 +1,72 @@
+/***************************************************************************
+ *   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.             *
+ ***************************************************************************/
+
+	.global main
+	.text
+	.set noreorder
+
+/* params:
+ * $a0 address in
+ * $a1 byte count
+ * vars
+ * $a0 crc
+ * $a1 crc data byte
+ * temps:
+ * t3 v0 a3 a2 t0 v1
+ */
+ 
+.ent main
+main:
+	addiu	$t4, $a0, 0		/* address in */
+	addiu	$t2, $a1, 0		/* count */
+
+	addiu	$a0, $zero, 0xffffffff /* a0 crc - result */
+
+	beq		$zero, $zero, ncomp
+	addiu	$t3, $zero, 0	/* clear bytes read */
+
+nbyte:
+	lb		$a1, ($t4)		/* load byte from source address */
+	addi	$t4, $t4, 1		/* inc byte count */
+
+crc:
+	sll		$a1, $a1, 24
+	lui		$v0, 0x04c1
+	xor		$a0, $a0, $a1
+	ori		$a3, $v0, 0x1db7
+	addu	$a2, $zero, $zero /* clear bit count */
+loop:
+	sll		$t0, $a0, 1
+	addiu	$a2, $a2, 1		/* inc bit count */
+	slti	$a0, $a0, 0
+	xor		$t1, $t0, $a3
+	movn	$t0, $t1, $a0
+	slti	$v1, $a2, 8		/* 8bits processed */
+	bne		$v1, $zero, loop
+	addu	$a0, $t0, $zero
+
+ncomp:
+	bne		$t2, $t3, nbyte	/* all bytes processed */
+	addiu	$t3, $t3, 1
+	
+wait:
+	sdbbp
+
+.end main