aturn

src/dusksaturn/log/log.c

@@ -6,27 +6,45 @@
  */
 
 #include "log/log.h"
+#include <dbgio.h>
+#include <stdarg.h>
 #include <stdio.h>
 
 /*
- * On Saturn, stdout goes to the debug serial port (via Yaul's dbgio module).
- * With a comm link or emulator (Mednafen, SSF) this is visible on the host.
- *
- * TODO: add dbgio_dev_default_set(DBGIO_DEV_USB_CART, NULL) in
- *       systemSaturnInit() and replace vprintf with dbgio_printf() for
- *       hardware-accurate serial output.
+ * Yaul's bare-metal stdio (stdout/stderr) has uninitialised function pointers
+ * and will crash if called via vprintf/vfprintf.  Use Yaul's dbgio subsystem
+ * instead: DBGIO_DEV_MEDNAFEN_DEBUG outputs to Mednafen's debug console;
+ * the same code works with USB cart or serial on hardware by changing the
+ * device constant.
  */
 
+static int _dbgioReady = 0;
+
+static void _ensureDbgio(void) {
+  if (!_dbgioReady) {
+    dbgio_dev_default_init(DBGIO_DEV_MEDNAFEN_DEBUG);
+    _dbgioReady = 1;
+  }
+}
+
+static void _logWrite(const char_t *message, va_list args) {
+  char buf[256];
+  vsnprintf(buf, sizeof(buf), message, args);
+  dbgio_puts(buf);
+}
+
 void logDebug(const char_t *message, ...) {
+  _ensureDbgio();
   va_list args;
   va_start(args, message);
-  vprintf(message, args);
+  _logWrite(message, args);
   va_end(args);
 }
 
 void logError(const char_t *message, ...) {
+  _ensureDbgio();
   va_list args;
   va_start(args, message);
-  vfprintf(stderr, message, args);
+  _logWrite(message, args);
   va_end(args);
 }