adding CS-Cipher

[avr-crypto-lib.git] / memxor / memxor_p.S

diff --git a/memxor/memxor_p.S b/memxor/memxor_p.S
new file mode 100644 (file)
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+/* memxor_p.s */
+/*
+    This file is part of the AVR-Crypto-Lib.
+    Copyright (C) 2006-2010 Daniel Otte (daniel.otte@rub.de)
+
+    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 3 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, see <http://www.gnu.org/licenses/>.
+*/
+
+/*
+ * File:        memxor.S
+ * Author:      Daniel Otte
+ * Date:        2008-08-07
+ * License:     GPLv3 or later
+ * Description: memxor, XORing one block into another
+ *
+ */
+
+/*
+ * void memxor(void* dest, const void* src, uint16_t n);
+ */
+ /*
+  * param dest is passed in r24:r25
+  * param src  is passed in r22:r23
+  * param n    is passed in r20:r21
+  */
+.global memxor_P
+memxor_P:
+       movw r26, r24
+       movw r30, r22
+       movw r24, r20
+       adiw r24, 0
+       breq 2f
+1:
+       lpm r20, Z+
+       ld r21, X
+       eor r20, r21
+       st X+, r20
+       sbiw r24, 1
+       brne 1b
+2:
+       ret