assert: Use printf_sync() to ensure printing of assert / panic

Change-Id: Icc202e60445d9be1cdcd61176db5ed1704d583e7

firmware/libcommon/include/assert.h

@@ -89,7 +89,7 @@
 		/// \param condition  Condition to verify.
 		#define ASSERT(condition)  { \
 			if (!(condition)) { \
-				printf("-F- ASSERT: %s %s:%d\n\r", #condition, __BASE_FILE__, __LINE__); \
+				printf_sync("-F- ASSERT: %s %s:%d\n\r", #condition, __BASE_FILE__, __LINE__); \
 				while (1); \
 			} \
 		}

firmware/libosmocore/source/panic.c

@@ -46,7 +46,7 @@ static osmo_panic_handler_t osmo_panic_handler = (void*)0;
 __attribute__ ((format (printf, 1, 0)))
 static void osmo_panic_default(const char *fmt, va_list args)
 {
-	vfprintf(stderr, fmt, args);
+	vfprintf_sync(stderr, fmt, args);
 	osmo_generate_backtrace();
 	assert(0);
 }

firmware/test/card_emu_tests.c

@@ -13,6 +13,20 @@
 #define PHONE_INT	2
 #define PHONE_DATAOUT	3
 
+/* stub for stdio */
+signed int printf_sync(const char *pFormat, ...)
+{
+	va_list ap;
+	signed int result;
+
+	va_start(ap, pFormat);
+	result = vprintf(pFormat, ap);
+	va_end(ap);
+
+	return result;
+}
+
+
 /***********************************************************************
  * stub functions required by card_emu.c
  ***********************************************************************/