fixed crash on home menu close

Debug/prboom.log

@@ -1 +1,44 @@
-  make[1]: Nothing to be done for `all'.
+  d_main.c
+  arm-none-eabi-gcc -MMD -MP -MF /c/devl/prboom3ds/build/d_main.d -g -Wall -O2 -mword-relocations -save-temps -fomit-frame-pointer -ffast-math -march=armv6k -mtune=mpcore -mfloat-abi=hard -mtp=soft -I/c/devl/prboom3ds/include -I/c/devl/prboom3ds/src -I/c/devl/prboom3ds/arm9/include -I/c/devl/prboom3ds/arm11/include -I/c/devl/prboom3ds/khax -I/c/devkitPro/libctru/include -I/c/devl/prboom3ds/build -DARM11 -D_3DS -DHAVE_CONFIG_H -c /c/devl/prboom3ds/src/d_main.c -o d_main.o 
+  c:/devl/prboom3ds/src/d_main.c: In function 'D_PostEvent':
+  c:/devl/prboom3ds/src/d_main.c(160):6: warning: value computed is not used [-Wunused-value]
+      ) ||
+        ^~
+  c:/devl/prboom3ds/src/d_main.c: In function 'D_Wipe':
+  c:/devl/prboom3ds/src/d_main.c(194):4: warning: implicit declaration of function 'copy_screen' [-Wimplicit-function-declaration]
+      copy_screen(GFX_LEFT);
+      ^~~~~~~~~~~
+  c:/devl/prboom3ds/src/d_main.c: In function 'D_Display':
+  c:/devl/prboom3ds/src/d_main.c(240):5: warning: case label value is less than minimum value for type
+       case -1:
+       ^~~~
+  c:/devl/prboom3ds/src/d_main.c: In function 'CheckIWAD':
+  c:/devl/prboom3ds/src/d_main.c(652):9: warning: implicit declaration of function 'access_3ds' [-Wimplicit-function-declaration]
+     if ( !access_3ds (iwadname,R_OK) )
+           ^~~~~~~~~~
+  c:/devl/prboom3ds/src/d_main.c: In function 'find_wads':
+  c:/devl/prboom3ds/src/d_main.c(804):22: warning: assignment makes integer from pointer without a cast [-Wint-conversion]
+     wads_found_path[i] = iwad;
+                        ^
+  c:/devl/prboom3ds/src/d_main.c: In function 'ds_game_choose':
+  c:/devl/prboom3ds/src/d_main.c(889):26: warning: return makes pointer from integer without a cast [-Wint-conversion]
+      return wads_found_path[wads_found[pos]];
+             ~~~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~
+  c:/devl/prboom3ds/src/d_main.c(882):8: warning: unused variable 'dhcp' [-Wunused-variable]
+      int dhcp = 0;
+          ^~~~
+  ds_main.c
+  arm-none-eabi-gcc -MMD -MP -MF /c/devl/prboom3ds/build/ds_main.d -g -Wall -O2 -mword-relocations -save-temps -fomit-frame-pointer -ffast-math -march=armv6k -mtune=mpcore -mfloat-abi=hard -mtp=soft -I/c/devl/prboom3ds/include -I/c/devl/prboom3ds/src -I/c/devl/prboom3ds/arm9/include -I/c/devl/prboom3ds/arm11/include -I/c/devl/prboom3ds/khax -I/c/devkitPro/libctru/include -I/c/devl/prboom3ds/build -DARM11 -D_3DS -DHAVE_CONFIG_H -c /c/devl/prboom3ds/arm9/source/ds_main.c -o ds_main.o 
+  c:/devl/prboom3ds/arm9/source/ds_main.c: In function 'sys_init':
+  c:/devl/prboom3ds/arm9/source/ds_main.c(80):2: warning: implicit declaration of function 'dkeyboard_init' [-Wimplicit-function-declaration]
+    dkeyboard_init();
+    ^~~~~~~~~~~~~~
+  c:/devl/prboom3ds/arm9/source/ds_main.c: In function 'main':
+  c:/devl/prboom3ds/arm9/source/ds_main.c(138):10: warning: assignment from incompatible pointer type [-Wincompatible-pointer-types]
+     myargv = argv;
+            ^
+  c:/devl/prboom3ds/arm9/source/ds_main.c(142):10: warning: assignment from incompatible pointer type [-Wincompatible-pointer-types]
+     myargv = "\0\0\0\0";// argv;
+            ^
+  linking prboom3ds.elf
+  built ... prboom3ds.3dsx

arm9/source/ds_main.c

@@ -52,6 +52,7 @@ void drawFrame()
 }
 
 int audio_initialized = 0;
+static u32 old_time_limit = UINT32_MAX;
 
 static void sys_init() {
 	gfxInitDefault();
@@ -90,6 +91,12 @@ static void sys_init() {
 
 	osSetSpeedupEnable(true);
 	//while (1);
+	//stolen from FBI - thanks steveice10
+	APT_GetAppCpuTimeLimit(&old_time_limit);
+	Result cpuRes = APT_SetAppCpuTimeLimit(30);
+	if (R_FAILED(cpuRes)) {
+		printf("Failed to set syscore CPU time limit: %08lX", cpuRes);
+	}
 }
 
 void I_Quit() {
@@ -100,6 +107,12 @@ void I_Quit() {
 		csndExit();
 		printf("csndExit ok!\n");
 	}
+	if (old_time_limit != UINT32_MAX) {
+		APT_SetAppCpuTimeLimit(old_time_limit);
+	}
+
+	gfxSet3D(false);
+	osSetSpeedupEnable(false);
 	//ndspExit();
 #if 0
 	khaxExit();

src/d_main.c

@@ -418,11 +418,6 @@ static void D_DoomLoop(void)
 		//gspWaitForEvent(GSPEVENT_VBlank0, false);
 	}
 
-	gfxExit();
-	irrstExit();
-	hidExit();
-	aptExit();
-	srvExit();
 }
 
 //