FS: Make EnsureSaveData create the savedata folder when called for the first time.

src/core/hle/service/am/am.cpp

@@ -2,12 +2,15 @@
 // Licensed under GPLv2 or any later version
 // Refer to the license.txt file included.
 
+#include <cinttypes>
+#include "core/file_sys/filesystem.h"
 #include "core/hle/ipc_helpers.h"
 #include "core/hle/kernel/event.h"
 #include "core/hle/service/am/am.h"
 #include "core/hle/service/am/applet_ae.h"
 #include "core/hle/service/am/applet_oe.h"
 #include "core/hle/service/apm/apm.h"
+#include "core/hle/service/filesystem/filesystem.h"
 #include "core/hle/service/nvflinger/nvflinger.h"
 
 namespace Service {
@@ -416,9 +419,24 @@ void IApplicationFunctions::PopLaunchParameter(Kernel::HLERequestContext& ctx) {
 }
 
 void IApplicationFunctions::EnsureSaveData(Kernel::HLERequestContext& ctx) {
-    LOG_WARNING(Service, "(STUBBED) called");
+    IPC::RequestParser rp{ctx};
+    u128 uid = rp.PopRaw<u128>();
+
+    LOG_WARNING(Service, "(STUBBED) called uid = %016" PRIX64 "%016" PRIX64, uid[1], uid[0]);
+
     IPC::ResponseBuilder rb{ctx, 4};
-    rb.Push(RESULT_SUCCESS);
+
+    FileSys::Path unused;
+    auto savedata = FileSystem::OpenFileSystem(FileSystem::Type::SaveData, unused);
+    if (savedata.Failed()) {
+        // Create the save data and return an error indicating that the operation was performed.
+        FileSystem::FormatFileSystem(FileSystem::Type::SaveData);
+        // TODO(Subv): Find out the correct error code for this.
+        rb.Push(ResultCode(ErrorModule::FS, 40));
+    } else {
+        rb.Push(RESULT_SUCCESS);
+    }
+
     rb.Push<u64>(0);
 }
 

src/core/hle/service/filesystem/filesystem.cpp

@@ -43,6 +43,19 @@ ResultVal<std::unique_ptr<FileSys::FileSystemBackend>> OpenFileSystem(Type type,
     return itr->second->Open(path);
 }
 
+ResultCode FormatFileSystem(Type type) {
+    LOG_TRACE(Service_FS, "Formatting FileSystem with type=%d", type);
+
+    auto itr = filesystem_map.find(type);
+    if (itr == filesystem_map.end()) {
+        // TODO(bunnei): Find a better error code for this
+        return ResultCode(-1);
+    }
+
+    FileSys::Path unused;
+    return itr->second->Format(unused);
+}
+
 void RegisterFileSystems() {
     filesystem_map.clear();
 

src/core/hle/service/filesystem/filesystem.h

@@ -44,6 +44,13 @@ ResultCode RegisterFileSystem(std::unique_ptr<FileSys::FileSystemFactory>&& fact
 ResultVal<std::unique_ptr<FileSys::FileSystemBackend>> OpenFileSystem(Type type,
                                                                       FileSys::Path& path);
 
+/**
+ * Formats a file system
+ * @param type Type of the file system to format
+ * @return ResultCode of the operation
+ */
+ResultCode FormatFileSystem(Type type);
+
 /// Registers all Filesystem services with the specified service manager.
 void InstallInterfaces(SM::ServiceManager& service_manager);