diff --git a/README.md b/README.md
index 5d10f9588..790278891 100755
--- a/README.md
+++ b/README.md
@@ -1,7 +1,7 @@
 yuzu emulator early access
 =============
 
-This is the source code for early-access 3920.
+This is the source code for early-access 3921.
 
 ## Legal Notice
 
diff --git a/src/audio_core/adsp/apps/audio_renderer/audio_renderer.cpp b/src/audio_core/adsp/apps/audio_renderer/audio_renderer.cpp
index 972d5e45b..0543589a7 100755
--- a/src/audio_core/adsp/apps/audio_renderer/audio_renderer.cpp
+++ b/src/audio_core/adsp/apps/audio_renderer/audio_renderer.cpp
@@ -77,6 +77,7 @@ void AudioRenderer::Wait() {
                   "{}, got {}",
                   Message::RenderResponse, msg);
     }
+    PostDSPClearCommandBuffer();
 }
 
 void AudioRenderer::Send(Direction dir, u32 message) {
@@ -96,6 +97,15 @@ void AudioRenderer::SetCommandBuffer(s32 session_id, CpuAddr buffer, u64 size, u
     command_buffers[session_id].reset_buffer = reset;
 }
 
+void AudioRenderer::PostDSPClearCommandBuffer() noexcept {
+    command_buffers[0].buffer = 0;
+    command_buffers[0].size = 0;
+    command_buffers[0].reset_buffer = false;
+    command_buffers[1].buffer = 0;
+    command_buffers[1].size = 0;
+    command_buffers[1].reset_buffer = false;
+}
+
 u32 AudioRenderer::GetRemainCommandCount(s32 session_id) const noexcept {
     return command_buffers[session_id].remaining_command_count;
 }
diff --git a/src/audio_core/adsp/apps/audio_renderer/audio_renderer.h b/src/audio_core/adsp/apps/audio_renderer/audio_renderer.h
index 85874d88a..57b89d9fe 100755
--- a/src/audio_core/adsp/apps/audio_renderer/audio_renderer.h
+++ b/src/audio_core/adsp/apps/audio_renderer/audio_renderer.h
@@ -85,6 +85,8 @@ private:
      */
     void CreateSinkStreams();
 
+    void PostDSPClearCommandBuffer() noexcept;
+
     /// Core system
     Core::System& system;
     /// The output sink the AudioRenderer will send samples to
diff --git a/src/core/hle/service/acc/acc.cpp b/src/core/hle/service/acc/acc.cpp
index a24698e4f..4259d2be7 100755
--- a/src/core/hle/service/acc/acc.cpp
+++ b/src/core/hle/service/acc/acc.cpp
@@ -49,7 +49,7 @@ public:
         : ServiceFramework{system_, "IManagerForSystemService"} {
         // clang-format off
         static const FunctionInfo functions[] = {
-            {0, nullptr, "CheckAvailability"},
+            {0, &IManagerForSystemService::CheckAvailability, "CheckAvailability"},
             {1, nullptr, "GetAccountId"},
             {2, nullptr, "EnsureIdTokenCacheAsync"},
             {3, nullptr, "LoadIdTokenCache"},
@@ -78,6 +78,13 @@ public:
 
         RegisterHandlers(functions);
     }
+
+private:
+    void CheckAvailability(HLERequestContext& ctx) {
+        LOG_WARNING(Service_ACC, "(STUBBED) called");
+        IPC::ResponseBuilder rb{ctx, 2};
+        rb.Push(ResultSuccess);
+    }
 };
 
 // 3.0.0+
@@ -400,8 +407,8 @@ protected:
         IPC::RequestParser rp{ctx};
         const auto base = rp.PopRaw<ProfileBase>();
 
-        const auto user_data = ctx.ReadBuffer();
-        const auto image_data = ctx.ReadBuffer(1);
+        const auto user_data = ctx.ReadBuffer(0);
+        const auto image_data = ctx.ReadBuffer(1); // TODO: Check if this buffer is always provided
 
         LOG_DEBUG(Service_ACC, "called, username='{}', timestamp={:016X}, uuid=0x{}",
                   Common::StringFromFixedZeroTerminatedBuffer(
@@ -837,6 +844,29 @@ void Module::Interface::InitializeApplicationInfoV2(HLERequestContext& ctx) {
     rb.Push(ResultSuccess);
 }
 
+void Module::Interface::BeginUserRegistration(HLERequestContext& ctx) {
+    const auto user_id = Common::UUID::MakeRandom();
+    profile_manager->CreateNewUser(user_id, "yuzu");
+
+    LOG_INFO(Service_ACC, "called, uuid={}", user_id.FormattedString());
+
+    IPC::ResponseBuilder rb{ctx, 6};
+    rb.Push(ResultSuccess);
+    rb.PushRaw(user_id);
+}
+
+void Module::Interface::CompleteUserRegistration(HLERequestContext& ctx) {
+    IPC::RequestParser rp{ctx};
+    Common::UUID user_id = rp.PopRaw<Common::UUID>();
+
+    LOG_INFO(Service_ACC, "called, uuid={}", user_id.FormattedString());
+
+    profile_manager->WriteUserSaveFile();
+
+    IPC::ResponseBuilder rb{ctx, 2};
+    rb.Push(ResultSuccess);
+}
+
 void Module::Interface::GetProfileEditor(HLERequestContext& ctx) {
     IPC::RequestParser rp{ctx};
     Common::UUID user_id = rp.PopRaw<Common::UUID>();
@@ -880,6 +910,17 @@ void Module::Interface::StoreSaveDataThumbnailApplication(HLERequestContext& ctx
     StoreSaveDataThumbnail(ctx, uuid, tid);
 }
 
+void Module::Interface::GetBaasAccountManagerForSystemService(HLERequestContext& ctx) {
+    IPC::RequestParser rp{ctx};
+    const auto uuid = rp.PopRaw<Common::UUID>();
+
+    LOG_INFO(Service_ACC, "called, uuid=0x{}", uuid.RawString());
+
+    IPC::ResponseBuilder rb{ctx, 2, 0, 1};
+    rb.Push(ResultSuccess);
+    rb.PushIpcInterface<IManagerForSystemService>(system, uuid);
+}
+
 void Module::Interface::StoreSaveDataThumbnailSystem(HLERequestContext& ctx) {
     IPC::RequestParser rp{ctx};
     const auto uuid = rp.PopRaw<Common::UUID>();
diff --git a/src/core/hle/service/acc/acc.h b/src/core/hle/service/acc/acc.h
index 1ea3efa0a..ab12f6554 100755
--- a/src/core/hle/service/acc/acc.h
+++ b/src/core/hle/service/acc/acc.h
@@ -33,10 +33,13 @@ public:
         void TrySelectUserWithoutInteraction(HLERequestContext& ctx);
         void IsUserAccountSwitchLocked(HLERequestContext& ctx);
         void InitializeApplicationInfoV2(HLERequestContext& ctx);
+        void BeginUserRegistration(HLERequestContext& ctx);
+        void CompleteUserRegistration(HLERequestContext& ctx);
         void GetProfileEditor(HLERequestContext& ctx);
         void ListQualifiedUsers(HLERequestContext& ctx);
         void ListOpenContextStoredUsers(HLERequestContext& ctx);
         void StoreSaveDataThumbnailApplication(HLERequestContext& ctx);
+        void GetBaasAccountManagerForSystemService(HLERequestContext& ctx);
         void StoreSaveDataThumbnailSystem(HLERequestContext& ctx);
 
     private:
diff --git a/src/core/hle/service/acc/acc_su.cpp b/src/core/hle/service/acc/acc_su.cpp
index 67612b5e8..89206065c 100755
--- a/src/core/hle/service/acc/acc_su.cpp
+++ b/src/core/hle/service/acc/acc_su.cpp
@@ -23,7 +23,7 @@ ACC_SU::ACC_SU(std::shared_ptr<Module> module_, std::shared_ptr<ProfileManager>
         {99, nullptr, "DebugActivateOpenContextRetention"},
         {100, nullptr, "GetUserRegistrationNotifier"},
         {101, nullptr, "GetUserStateChangeNotifier"},
-        {102, nullptr, "GetBaasAccountManagerForSystemService"},
+        {102, &ACC_SU::GetBaasAccountManagerForSystemService, "GetBaasAccountManagerForSystemService"},
         {103, nullptr, "GetBaasUserAvailabilityChangeNotifier"},
         {104, nullptr, "GetProfileUpdateNotifier"},
         {105, nullptr, "CheckNetworkServiceAvailabilityAsync"},
@@ -40,8 +40,8 @@ ACC_SU::ACC_SU(std::shared_ptr<Module> module_, std::shared_ptr<ProfileManager>
         {152, nullptr, "LoadSignedDeviceIdentifierCacheForNintendoAccount"},
         {190, nullptr, "GetUserLastOpenedApplication"},
         {191, nullptr, "ActivateOpenContextHolder"},
-        {200, nullptr, "BeginUserRegistration"},
-        {201, nullptr, "CompleteUserRegistration"},
+        {200, &ACC_SU::BeginUserRegistration, "BeginUserRegistration"},
+        {201, &ACC_SU::CompleteUserRegistration, "CompleteUserRegistration"},
         {202, nullptr, "CancelUserRegistration"},
         {203, nullptr, "DeleteUser"},
         {204, nullptr, "SetUserPosition"},
diff --git a/src/core/hle/service/acc/profile_manager.h b/src/core/hle/service/acc/profile_manager.h
index e4a7eb2ce..f1deddebc 100755
--- a/src/core/hle/service/acc/profile_manager.h
+++ b/src/core/hle/service/acc/profile_manager.h
@@ -96,9 +96,10 @@ public:
     bool SetProfileBaseAndData(Common::UUID uuid, const ProfileBase& profile_new,
                                const UserData& data_new);
 
+    void WriteUserSaveFile();
+
 private:
     void ParseUserSaveFile();
-    void WriteUserSaveFile();
     std::optional<std::size_t> AddToProfiles(const ProfileInfo& profile);
     bool RemoveProfileAtIndex(std::size_t index);
 
diff --git a/src/core/hle/service/am/am.cpp b/src/core/hle/service/am/am.cpp
index 5a9e7a3d8..8d6aa3bb8 100755
--- a/src/core/hle/service/am/am.cpp
+++ b/src/core/hle/service/am/am.cpp
@@ -1557,7 +1557,7 @@ ILibraryAppletSelfAccessor::ILibraryAppletSelfAccessor(Core::System& system_)
         {100, nullptr, "CreateGameMovieTrimmer"},
         {101, nullptr, "ReserveResourceForMovieOperation"},
         {102, nullptr, "UnreserveResourceForMovieOperation"},
-        {110, nullptr, "GetMainAppletAvailableUsers"},
+        {110, &ILibraryAppletSelfAccessor::GetMainAppletAvailableUsers, "GetMainAppletAvailableUsers"},
         {120, nullptr, "GetLaunchStorageInfoForDebug"},
         {130, nullptr, "GetGpuErrorDetectedSystemEvent"},
         {140, nullptr, "SetApplicationMemoryReservation"},
@@ -1652,6 +1652,25 @@ void ILibraryAppletSelfAccessor::GetCallerAppletIdentityInfo(HLERequestContext&
     rb.PushRaw(applet_info);
 }
 
+void ILibraryAppletSelfAccessor::GetMainAppletAvailableUsers(HLERequestContext& ctx) {
+    const Service::Account::ProfileManager manager{};
+    bool is_empty{true};
+    s32 user_count{-1};
+
+    LOG_INFO(Service_AM, "called");
+
+    if (manager.GetUserCount() > 0) {
+        is_empty = false;
+        user_count = static_cast<s32>(manager.GetUserCount());
+        ctx.WriteBuffer(manager.GetAllUsers());
+    }
+
+    IPC::ResponseBuilder rb{ctx, 4};
+    rb.Push(ResultSuccess);
+    rb.Push<u8>(is_empty);
+    rb.Push(user_count);
+}
+
 void ILibraryAppletSelfAccessor::PushInShowAlbum() {
     const Applets::CommonArguments arguments{
         .arguments_version = Applets::CommonArgumentVersion::Version3,
diff --git a/src/core/hle/service/am/am.h b/src/core/hle/service/am/am.h
index 401dcc5df..d8ec3c225 100755
--- a/src/core/hle/service/am/am.h
+++ b/src/core/hle/service/am/am.h
@@ -345,6 +345,7 @@ private:
     void GetLibraryAppletInfo(HLERequestContext& ctx);
     void ExitProcessAndReturn(HLERequestContext& ctx);
     void GetCallerAppletIdentityInfo(HLERequestContext& ctx);
+    void GetMainAppletAvailableUsers(HLERequestContext& ctx);
 
     void PushInShowAlbum();
     void PushInShowCabinetData();
diff --git a/src/video_core/vulkan_common/vulkan_memory_allocator.cpp b/src/video_core/vulkan_common/vulkan_memory_allocator.cpp
index 4b52563c7..077ee68cb 100755
--- a/src/video_core/vulkan_common/vulkan_memory_allocator.cpp
+++ b/src/video_core/vulkan_common/vulkan_memory_allocator.cpp
@@ -66,9 +66,10 @@ struct Range {
     switch (usage) {
     case MemoryUsage::Upload:
     case MemoryUsage::Stream:
-        return VMA_ALLOCATION_CREATE_HOST_ACCESS_SEQUENTIAL_WRITE_BIT;
+        return VMA_ALLOCATION_CREATE_MAPPED_BIT |
+               VMA_ALLOCATION_CREATE_HOST_ACCESS_SEQUENTIAL_WRITE_BIT;
     case MemoryUsage::Download:
-        return VMA_ALLOCATION_CREATE_HOST_ACCESS_RANDOM_BIT;
+        return VMA_ALLOCATION_CREATE_MAPPED_BIT | VMA_ALLOCATION_CREATE_HOST_ACCESS_RANDOM_BIT;
     case MemoryUsage::DeviceLocal:
         return {};
     }
@@ -252,8 +253,7 @@ vk::Image MemoryAllocator::CreateImage(const VkImageCreateInfo& ci) const {
 
 vk::Buffer MemoryAllocator::CreateBuffer(const VkBufferCreateInfo& ci, MemoryUsage usage) const {
     const VmaAllocationCreateInfo alloc_ci = {
-        .flags = VMA_ALLOCATION_CREATE_WITHIN_BUDGET_BIT | VMA_ALLOCATION_CREATE_MAPPED_BIT |
-                 MemoryUsageVmaFlags(usage),
+        .flags = VMA_ALLOCATION_CREATE_WITHIN_BUDGET_BIT | MemoryUsageVmaFlags(usage),
         .usage = MemoryUsageVma(usage),
         .requiredFlags = 0,
         .preferredFlags = MemoryUsagePreferedVmaFlags(usage),