feat: Make firmware mandatory for title launching

This commit implements a requirement for firmware to be installed before titles
can be launched, similar to how keys are required.

Changes include:
- Add IsFirmwareAvailable method to KeyManager to check for essential keys
- Add CheckFirmwarePresence method to verify actual firmware files (NCAs)
- Add firmware checks in game loading process for both desktop and Android
- Add error messages when firmware is missing
- Add strings for firmware-related error messages

The implementation checks for both essential keys and the presence of system
applets like Mii Edit and Home Menu to ensure proper firmware is installed.
Games will not launch if firmware is missing, and users will be shown an
appropriate error message.

src/core/crypto/key_manager.cpp

@@ -1290,4 +1290,31 @@ bool KeyManager::AddTicket(const Ticket& ticket) {
     SetKey(S128KeyType::Titlekey, key.value(), rights_id[1], rights_id[0]);
     return true;
 }
+
+bool KeyManager::IsFirmwareAvailable() const {
+    // Check for essential keys that would only be present with firmware
+    if (!HasKey(S128KeyType::Master, 0)) {
+        return false;
+    }
+
+    // Check for at least one titlekek
+    bool has_titlekek = false;
+    for (size_t i = 0; i < CURRENT_CRYPTO_REVISION; ++i) {
+        if (HasKey(S128KeyType::Titlekek, i)) {
+            has_titlekek = true;
+            break;
+        }
+    }
+
+    if (!has_titlekek) {
+        return false;
+    }
+
+    // Check for header key
+    if (!HasKey(S256KeyType::Header)) {
+        return false;
+    }
+
+    return true;
+}
 } // namespace Core::Crypto

src/core/crypto/key_manager.h

@@ -296,6 +296,9 @@ public:
     void ReloadKeys();
     bool AreKeysLoaded() const;
 
+    // Check if firmware is installed by verifying essential keys
+    bool IsFirmwareAvailable() const;
+
 private:
     KeyManager();
 

src/core/file_sys/content_manager.cpp

@@ -0,0 +1,25 @@
+#include "core/system.h"
+#include "core/file_sys/registered_cache.h"
+#include "core/file_sys/content_archive.h"
+#include "core/crypto/key_manager.h"
+
+bool ContentManager::IsFirmwareAvailable() {
+    constexpr u64 MiiEditId = 0x0100000000001009; // Mii Edit applet ID
+    constexpr u64 QLaunchId = 0x0100000000001000; // Home Menu applet ID
+
+    auto& system = Core::System::GetInstance();
+    auto bis_system = system.GetFileSystemController().GetSystemNANDContents();
+    if (!bis_system) {
+        return false;
+    }
+
+    auto mii_applet_nca = bis_system->GetEntry(MiiEditId, FileSys::ContentRecordType::Program);
+    auto qlaunch_nca = bis_system->GetEntry(QLaunchId, FileSys::ContentRecordType::Program);
+
+    if (!mii_applet_nca || !qlaunch_nca) {
+        return false;
+    }
+
+    // Also check for essential keys
+    return Core::Crypto::KeyManager::Instance().IsFirmwareAvailable();
+}

src/core/loader/loader.cpp

@@ -19,6 +19,10 @@
 #include "core/loader/nso.h"
 #include "core/loader/nsp.h"
 #include "core/loader/xci.h"
+#include "core/hle/service/am/am.h"
+#include "core/hle/service/filesystem/filesystem.h"
+#include "core/file_sys/registered_cache.h"
+#include "core/file_sys/content_archive.h"
 
 namespace Loader {
 
@@ -250,6 +254,20 @@ std::unique_ptr<AppLoader> GetLoader(Core::System& system, FileSys::VirtualFile
         return nullptr;
     }
 
+    // Check if firmware is available
+    constexpr u64 MiiEditId = 0x0100000000001009; // Mii Edit applet ID
+    auto bis_system = system.GetFileSystemController().GetSystemNANDContents();
+    if (bis_system) {
+        auto mii_applet_nca = bis_system->GetEntry(MiiEditId, FileSys::ContentRecordType::Program);
+        if (!mii_applet_nca) {
+            LOG_ERROR(Loader, "Firmware is required to launch games but is not available");
+            return nullptr;
+        }
+    } else {
+        LOG_ERROR(Loader, "System NAND contents not available");
+        return nullptr;
+    }
+
     FileType type = IdentifyFile(file);
     const FileType filename_type = GuessFromFilename(file->GetName());