Add a consistent feature check - only desktops get to use CacheFullISOInRAM.

Common/System/System.h

@@ -219,6 +219,8 @@ enum SystemProperty {
 
 	SYSPROP_CAN_READ_BATTERY_PERCENTAGE,
 	SYSPROP_BATTERY_PERCENTAGE,
+
+	SYSPROP_ENOUGH_RAM_FOR_FULL_ISO,
 };
 
 enum class SystemNotification {

Core/FileLoaders/RamCachingFileLoader.cpp

@@ -21,6 +21,7 @@
 
 #include "Common/Thread/ThreadUtil.h"
 #include "Common/TimeUtil.h"
+#include "Common/Log.h"
 #include "Core/FileLoaders/RamCachingFileLoader.h"
 
 // Takes ownership of backend.
@@ -91,6 +92,7 @@ void RamCachingFileLoader::InitCache() {
 	// Overallocate for the last block.
 	cache_ = (u8 *)malloc((size_t)blockCount << BLOCK_SHIFT);
 	if (cache_ == nullptr) {
+		ERROR_LOG(Log::IO, "Failed to allocate cache for Cache full ISO in RAM! Will fall back to regular reads.");
 		return;
 	}
 	aheadRemaining_ = blockCount;
@@ -178,6 +180,8 @@ void RamCachingFileLoader::SaveIntoCache(s64 pos, size_t bytes, Flags flags) {
 				if (blocksToRead >= MAX_BLOCKS_PER_READ) {
 					break;
 				}
+
+				// TODO: Shouldn't we break as soon as we see a 1?
 			}
 		}
 	}

Core/System.cpp

@@ -425,6 +425,7 @@ bool PSP_InitStart(const CoreParameter &coreParam, std::string *error_string) {
 	IdentifiedFileType type = Identify_File(loadedFile, &g_CoreParameter.errorString);
 	g_CoreParameter.fileType = type;
 
+	if (System_GetPropertyBool(SYSPROP_ENOUGH_RAM_FOR_FULL_ISO)) {
 		if (g_Config.bCacheFullIsoInRam) {
 			switch (g_CoreParameter.fileType) {
 			case IdentifiedFileType::PSP_ISO:
@@ -436,6 +437,7 @@ bool PSP_InitStart(const CoreParameter &coreParam, std::string *error_string) {
 				break;
 			}
 		}
+	}
 
 	if (g_Config.bAchievementsEnable) {
 		// Need to re-identify after ResolveFileLoaderTarget - although in practice probably not,

SDL/SDLMain.cpp

@@ -625,7 +625,13 @@ bool System_GetPropertyBool(SystemProperty prop) {
 #endif
 	case SYSPROP_CAN_READ_BATTERY_PERCENTAGE:
 		return true;
-default:
+	case SYSPROP_ENOUGH_RAM_FOR_FULL_ISO:
+#if defined(MOBILE_DEVICE)
+		return false;
+#else
+		return true;
+#endif
+	default:
 		return false;
 	}
 }

UI/GameSettingsScreen.cpp

@@ -1341,7 +1341,10 @@ void GameSettingsScreen::CreateSystemSettings(UI::ViewGroup *systemSettings) {
 	if (System_GetPropertyBool(SYSPROP_HAS_KEYBOARD))
 		systemSettings->Add(new CheckBox(&g_Config.bBypassOSKWithKeyboard, sy->T("Use system native keyboard")));
 
+	if (System_GetPropertyBool(SYSPROP_ENOUGH_RAM_FOR_FULL_ISO)) {
 		systemSettings->Add(new CheckBox(&g_Config.bCacheFullIsoInRam, sy->T("Cache ISO in RAM", "Cache full ISO in RAM")))->SetEnabled(!PSP_IsInited());
+	}
+
 	systemSettings->Add(new CheckBox(&g_Config.bCheckForNewVersion, sy->T("VersionCheck", "Check for new versions of PPSSPP")));
 	systemSettings->Add(new CheckBox(&g_Config.bScreenshotsAsPNG, sy->T("Screenshots as PNG")));
 	static const char *screenshotModeChoices[] = { "Final processed image", "Raw game image" };

Windows/main.cpp

@@ -406,6 +406,8 @@ bool System_GetPropertyBool(SystemProperty prop) {
 		return true;
 	case SYSPROP_CAN_READ_BATTERY_PERCENTAGE:
 		return true;
+	case SYSPROP_ENOUGH_RAM_FOR_FULL_ISO:
+		return true;
 	default:
 		return false;
 	}