Add support for Siemens SX1 mobile phone;

add support for USB-based console
(enable with "setenv stdout usbtty; setenv stdin usbtty")

include/circbuf.h

@@ -0,0 +1,40 @@
+/*
+ * (C) Copyright 2003
+ * Gerry Hamel, geh@ti.com, Texas Instruments
+ *
+ * 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
+ *
+ */
+
+#ifndef __CIRCBUF_H__
+#define __CIRCBUF_H__
+
+typedef struct circbuf {
+	unsigned int size;	/* current number of bytes held */
+	unsigned int totalsize; /* number of bytes allocated */
+
+	char *top;		/* pointer to current buffer start */
+	char *tail;		/* pointer to space for next element */
+
+	char *data;		/* all data */
+	char *end;		/* end of data buffer */
+} circbuf_t;
+
+int buf_init (circbuf_t * buf, unsigned int size);
+int buf_free (circbuf_t * buf);
+int buf_pop (circbuf_t * buf, char *dest, unsigned int len);
+int buf_push (circbuf_t * buf, const char *src, unsigned int len);
+
+#endif