arm: add uart echo app

arm/hal/lib/common/print.c

@@ -0,0 +1,36 @@
+/* print.c -- print a string on the output device.
+ *
+ * Copyright (c) 1995 Cygnus Support
+ *
+ * The authors hereby grant permission to use, copy, modify, distribute,
+ * and license this software and its documentation for any purpose, provided
+ * that existing copyright notices are retained in all copies and that this
+ * notice is included verbatim in any distributions. No written agreement,
+ * license, or royalty fee is required for any of the authorized uses.
+ * Modifications to this software may be copyrighted by their authors
+ * and need not follow the licensing terms described here, provided that
+ * the new terms are clearly indicated on the first page of each file where
+ * they apply.
+ *
+ */
+
+/*
+ * print -- do a raw print of a string
+ */
+#include "xil_printf.h"
+
+void print(const char8 *ptr)
+{
+#if defined (__aarch64__) && (HYP_GUEST == 1) && (EL1_NONSECURE == 1) && defined (XEN_USE_PV_CONSOLE)
+	XPVXenConsole_Write(ptr);
+#else
+#ifdef STDOUT_BASEADDRESS
+  while (*ptr != (char8)0) {
+    outbyte (*ptr);
+	ptr++;
+  }
+#else
+(void)ptr;
+#endif
+#endif
+}