add USB Gecko debugging support

Makefile.griffin

@@ -98,12 +98,18 @@ else ifeq ($(platform), wii)
   MACHDEP := -DGEKKO -DHW_RVL -mrvl -mcpu=750 -meabi -mhard-float -DMSB_FIRST
   LDFLAGS += $(MACHDEP) -Wl,-Map,$(notdir $(EXT_INTER_TARGET)).map,-wrap,malloc,-wrap,free,-wrap,memalign,-wrap,calloc,-wrap,realloc,-wrap,strdup,-wrap,strndup,-wrap,malloc_usable_size
 ifeq ($(BIG_STACK), 1)
-   LDFLAGS += -T gx/ld/rvl.ld
+  LDFLAGS += -T gx/ld/rvl.ld
+endif
+  LIBS := -lfat $(WHOLE_START) -lretro_wii $(WHOLE_END) -logc -lwiiuse -lbte
+ifeq ($(USBGECKO), 1)
+  LIBS += -ldb
 endif
-  LIBS := -lfat $(WHOLE_START) -lretro_wii $(WHOLE_END) -logc -lwiiuse -lbte 
   APP_BOOTER_DIR = wii/app_booter
   PLATOBJS := $(APP_BOOTER_DIR)/app_booter.binobj
   PLATCFLAGS := -DGEKKO
+ifeq ($(USBGECKO), 1)
+  PLATCFLAGS += -DUSBGECKO
+endif
 
   HAVE_FILTERS_BUILTIN     := 1
   HAVE_RARCH_EXEC          := 1

frontend/platform/platform_gx.c

@@ -50,6 +50,10 @@ extern void system_exec_wii(const char *path, bool should_load_game);
 #include <sdcard/gcsd.h>
 #include <fat.h>
 
+#ifdef USBGECKO
+#include <debug.h>
+#endif
+
 static bool exit_spawn = false;
 static bool exitspawn_start_game = false;
 
@@ -250,6 +254,11 @@ static void frontend_gx_init(void *data)
 #endif
 #endif
 
+#ifdef USBGECKO
+   DEBUG_Init(GDBSTUB_DEVICE_USB, 1);
+   _break();
+#endif
+
 #if defined(DEBUG) && defined(IS_SALAMANDER)
    VIDEO_Init();
    GXRModeObj *rmode = VIDEO_GetPreferredMode(NULL);