get the sam7ex256 platform building again

platform/at91sam7/debug.c

@@ -64,6 +64,12 @@ void ser_puts(const char *s)
     }
 }
 
+int dgetc(char *c, bool wait)
+{
+	return -1;
+}
+
+
 void _dputc(char c)
 {
 	ser_putc(c);

platform/at91sam7/timer.c

@@ -48,6 +48,11 @@ time_t current_time(void)
 	return ticks;
 }
 
+bigtime_t current_time_hires(void)
+{
+	return ticks * 1000ULL;
+}
+
 static enum handler_return pit_irq_handler(void *arg)
 {
     AT91PIT *pit = AT91PIT_ADDR;

scripts/do-sam7ex256-test

@@ -1,6 +1,6 @@
 #!/bin/sh
 
-export DEBUG=true
+export DEBUG=2
 export PROJECT=sam7ex256-test
 
 make