Added runtime (kernel 2.0)

runtime/io/vx_io.h

@@ -0,0 +1,10 @@
+
+#pragma once
+
+#include <stdbool.h>
+
+static char * hextoa[] = {"0", "1", "2", "3", "4", "5", "6", "7", "8", "9", "a", "b", "c", "d", "e", "f"};
+void vx_print_hex(unsigned);
+void vx_print_str(char *);
+void vx_printf(char *, unsigned);
+void vx_printc(unsigned, char c);