Do not disable backlight on o2DS

Source/platform/ctr/cfgu_service.hpp

@@ -0,0 +1,40 @@
+#pragma once
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+#include <3ds/result.h>
+#include <3ds/services/cfgu.h>
+
+#ifdef __cplusplus
+}
+#endif
+
+namespace devilution {
+namespace n3ds {
+
+class CFGUService {
+public:
+	CFGUService()
+	{
+		Result res = cfguInit();
+		isInitialized = R_SUCCEEDED(res);
+	}
+
+	~CFGUService()
+	{
+		cfguExit();
+	}
+
+	bool IsInitialized()
+	{
+		return isInitialized;
+	}
+
+private:
+	bool isInitialized;
+};
+
+} // namespace n3ds
+} // namespace devilution

Source/platform/ctr/locale.cpp

@@ -1,34 +1,19 @@
-#include "platform/ctr/locale.hpp"
-
 #include <3ds.h>
 
+#include "platform/ctr/cfgu_service.hpp"
+#include "platform/ctr/locale.hpp"
+
 namespace devilution {
 namespace n3ds {
 
-namespace {
-
-class CFGUService {
-public:
-	CFGUService()
-	{
-		cfguInit();
-	}
-
-	~CFGUService()
-	{
-		cfguExit();
-	}
-};
-
-} // namespace
-
 std::string GetLocale()
 {
 	CFGUService cfguService;
+	if (!cfguService.IsInitialized())
+		return "";
 
 	u8 language;
 	Result res = CFGU_GetSystemLanguage(&language);
-
 	if (!R_SUCCEEDED(res))
 		return "";
 

Source/platform/ctr/system.cpp

@@ -1,13 +1,15 @@
+#include <3ds.h>
 #include <cstdlib>
 #include <cstdio>
-#include <3ds.h>
-#include "platform/ctr/system.h"
+
+#include "platform/ctr/cfgu_service.hpp"
 #include "platform/ctr/random.hpp"
 #include "platform/ctr/sockets.hpp"
+#include "platform/ctr/system.h"
 
 using namespace devilution;
 
-bool isN3DS;
+bool shouldDisableBacklight;
 
 aptHookCookie cookie;
 
@@ -35,6 +37,8 @@ void aptHookFunc(APT_HookType hookType, void *param)
 
 void ctr_lcd_backlight_on()
 {
+	if (!shouldDisableBacklight)
+		return;
 	gspLcdInit();
 	GSPLCD_PowerOnBacklight(GSPLCD_SCREEN_BOTTOM);
 	gspLcdExit();
@@ -42,6 +46,8 @@ void ctr_lcd_backlight_on()
 
 void ctr_lcd_backlight_off()
 {
+	if (!shouldDisableBacklight)
+		return;
 	gspLcdInit();
 	GSPLCD_PowerOffBacklight(GSPLCD_SCREEN_BOTTOM);
 	gspLcdExit();
@@ -63,6 +69,27 @@ bool ctr_check_dsp()
 	return true;
 }
 
+bool ctr_is_n3ds()
+{
+	bool isN3DS;
+	Result res = APT_CheckNew3DS(&isN3DS);
+	return R_SUCCEEDED(res) && isN3DS;
+}
+
+bool ctr_should_disable_backlight()
+{
+	n3ds::CFGUService cfguService;
+	if (!cfguService.IsInitialized())
+		return false;
+
+	u8 model;
+	Result res = CFGU_GetSystemModel(&model);
+	if (!R_SUCCEEDED(res))
+		return false;
+
+	return model != CFG_MODEL_2DS;
+}
+
 void ctr_sys_init()
 {
 	if (ctr_check_dsp() == false)
@@ -70,10 +97,11 @@ void ctr_sys_init()
 
 	aptHook(&cookie, aptHookFunc, NULL);
 
-	APT_CheckNew3DS(&isN3DS);
-	if (isN3DS)
+	if (ctr_is_n3ds())
 		osSetSpeedupEnable(true);
 
+	shouldDisableBacklight = ctr_should_disable_backlight();
+
 	ctr_lcd_backlight_off();
 	atexit([]() { ctr_lcd_backlight_on(); });