init memcards only when necessary

src/engine/mcrd.c

@@ -6,7 +6,6 @@
 #include <libetc.h>
 
 #include "engine/common.h"
-#include "engine/timer.h"
 #include "engine/mcrd.h"
 
 #define MCRD_SAVE_MAGIC "CSS\x01"
@@ -45,6 +44,8 @@ static u8 save_icon_data[] = {
 #include "saveicon.inc"
 };
 
+static bool mcrd_init_done = FALSE;
+
 static inline char *mcrd_devname(const int chan) {
   static char buf[6] = "bu00:";
   buf[2] = '0' + (chan / 16); // port
@@ -118,12 +119,15 @@ void mcrd_init(void) {
 
   ExitCriticalSection();
 
+  mcrd_init_done = TRUE;
+
   printf("mcrd_init(): memcard initialized\n");
 }
 
 void mcrd_start(void) {
-  // tick music in the timer callback because all memcard processing is synchronous
-  timer_set_callback(timer_cb_music);
+  // call InitCARD and open events if we haven't done it already
+  if (!mcrd_init_done)
+    mcrd_init();
 
   mcrd_clear_events(MCRD_EV_HW);
   mcrd_clear_events(MCRD_EV_SW);
@@ -155,9 +159,6 @@ void mcrd_stop(void) {
   }
   ExitCriticalSection();
 
-  // reset timer back to normal callback
-  timer_set_callback(timer_cb_ticker);
-
   printf("mcrd_stop(): memcard processing stopped\n");
 }
 

src/game/menu.c

@@ -5,6 +5,7 @@
 #include "engine/memory.h"
 #include "engine/sound.h"
 #include "engine/input.h"
+#include "engine/timer.h"
 #include "engine/org.h"
 #include "engine/mcrd.h"
 
@@ -750,6 +751,13 @@ static inline void menu_saveload_set_state(const int state, const char *title, c
 }
 
 static void menu_saveload_open(void) {
+  // tick music in the timer callback because all memcard processing is synchronous
+  timer_set_callback(timer_cb_music);
+
+  // clear screen to show that something is actually happening
+  gfx_draw_clear_immediate(main_bg_rgb);
+
+  // ...since this takes a while the first time
   mcrd_start();
 
   saveload.num_cards = mcrd_cards_available(saveload.cards);
@@ -765,7 +773,13 @@ static void menu_saveload_open(void) {
 
 static inline void menu_saveload_close(const bool success) {
   mcrd_stop();
+
+  // reset timer back to normal callback
+  timer_set_callback(timer_cb_ticker);
+
+  // close menu
   menu_id = 0;
+
   // if we're in the intro stage, re-open the main menu
   if (!stage_data || stage_data->id == STAGE_OPENING_ID) {
     menu_open(MENU_TITLE);

src/main.c

@@ -20,7 +20,6 @@ int main(int argc, char **argv) {
   snd_init(SFX_MAIN_BANK);
   org_init();
   in_init();
-  mcrd_init();
 
   // load main graphics bank
   gfx_load_gfx_bank(GFX_MAIN_BANK);