add progmem compatible debug and info functions

avr/usbload/debug.h

@@ -26,7 +26,7 @@
 #include <stdlib.h>
 #include <stdint.h>
 #include <stdarg.h>
-
+#include <avr/pgmspace.h>
 
 #if defined(NO_DEBUG) && defined(__GNUC__)
 /* gcc's cpp has extensions; it allows for macros with a variable number of
@@ -39,5 +39,17 @@ void debug(int level, char *format, ...);
 #endif
 
 
+
+#if defined(NO_DEBUG) && defined(__GNUC__)
+/* gcc's cpp has extensions; it allows for macros with a variable number of
+   arguments. We use this extension here to preprocess pmesg away. */
+#define debug_P(level, format, args...) ((void)0)
+#else
+void debug_P(int level, PGM_P format, ...);
+/* print a message, if it is considered significant enough.
+      Adapted from [K&R2], p. 174 */
+#endif
+
+
 #endif /* DEBUG_H */