1 files changed, 39 insertions, 0 deletions

diff --git a/firmware/asm/arm/beep.c b/firmware/asm/arm/beep.c
new file mode 100644
index 0000000000..f3c3e2e0d2
--- /dev/null
+++ b/firmware/asm/arm/beep.c
@@ -0,0 +1,39 @@
+/***************************************************************************
+ *             __________               __   ___.
+ *   Open      \______   \ ____   ____ |  | _\_ |__   _______  ___
+ *   Source     |       _//  _ \_/ ___\|  |/ /| __ \ /  _ \  \/  /
+ *   Jukebox    |    |   (  <_> )  \___|    < | \_\ (  <_> > <  <
+ *   Firmware   |____|_  /\____/ \___  >__|_ \|___  /\____/__/\_ \
+ *                     \/            \/     \/    \/            \/
+ * $Id$
+ *
+ * Copyright (c) 2011 Michael Sevakis
+ *
+ * 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 software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
+ * KIND, either express or implied.
+ *
+ ****************************************************************************/
+
+/* Actually output samples into beep_buf */
+static FORCE_INLINE void beep_generate(uint32_t *out, int count,
+                                       int32_t *phase, uint32_t step,
+                                       uint32_t amplitude)
+{
+    uint32_t s;
+
+    asm volatile (
+    "1:                            \n"
+        "eor   %3, %5, %1, asr #31 \n"
+        "subs  %2, %2, #1          \n"
+        "str   %3, [%0], #4        \n"
+        "add   %1, %1, %4          \n"
+        "bgt   1b                  \n"
+        : "+r"(out), "+r"(*phase), "+r"(count),
+          "=&r"(s)
+        : "r"(step), "r"(amplitude));
+}