6 files changed, 36 insertions, 5 deletions

diff --git a/src/core/hle/applets/applet.cpp b/src/core/hle/applets/applet.cpp
index e9ab6ffd8..bc2a1829e 100644
--- a/src/core/hle/applets/applet.cpp
+++ b/src/core/hle/applets/applet.cpp
@@ -91,7 +91,7 @@ ResultCode Applet::Start(const Service::APT::AppletStartupParameter& parameter)
 
 bool IsLibraryAppletRunning() {
     // Check the applets map for instances of any applet
-    for (auto& itr = applets.begin(); itr != applets.end(); ++itr)
+    for (auto itr = applets.begin(); itr != applets.end(); ++itr)
         if (itr->second != nullptr)
             return true;
     return false;
diff --git a/src/core/hle/service/apt/apt.cpp b/src/core/hle/service/apt/apt.cpp
index 1988be521..35402341b 100644
--- a/src/core/hle/service/apt/apt.cpp
+++ b/src/core/hle/service/apt/apt.cpp
@@ -334,7 +334,26 @@ void GetAppCpuTimeLimit(Service::Interface* self) {
 void PrepareToStartLibraryApplet(Service::Interface* self) {
     u32* cmd_buff = Kernel::GetCommandBuffer();
     AppletId applet_id = static_cast<AppletId>(cmd_buff[1]);
-    cmd_buff[1] = HLE::Applets::Applet::Create(applet_id).raw;
+    auto applet = HLE::Applets::Applet::Get(applet_id);
+    if (applet) {
+        LOG_WARNING(Service_APT, "applet has already been started id=%08X", applet_id);
+        cmd_buff[1] = RESULT_SUCCESS.raw;
+    } else {
+        cmd_buff[1] = HLE::Applets::Applet::Create(applet_id).raw;
+    }
+    LOG_DEBUG(Service_APT, "called applet_id=%08X", applet_id);
+}
+
+void PreloadLibraryApplet(Service::Interface* self) {
+    u32* cmd_buff = Kernel::GetCommandBuffer();
+    AppletId applet_id = static_cast<AppletId>(cmd_buff[1]);
+    auto applet = HLE::Applets::Applet::Get(applet_id);
+    if (applet) {
+        LOG_WARNING(Service_APT, "applet has already been started id=%08X", applet_id);
+        cmd_buff[1] = RESULT_SUCCESS.raw;
+    } else {
+        cmd_buff[1] = HLE::Applets::Applet::Create(applet_id).raw;
+    }
     LOG_DEBUG(Service_APT, "called applet_id=%08X", applet_id);
 }
 
diff --git a/src/core/hle/service/apt/apt.h b/src/core/hle/service/apt/apt.h
index 563068d5a..4a72b6b5c 100644
--- a/src/core/hle/service/apt/apt.h
+++ b/src/core/hle/service/apt/apt.h
@@ -303,6 +303,17 @@ void GetAppCpuTimeLimit(Service::Interface* self);
 void PrepareToStartLibraryApplet(Service::Interface* self);
 
 /**
+ * APT::PreloadLibraryApplet service function
+ *  Inputs:
+ *      0 : Command header [0x00160040]
+ *      1 : Id of the applet to start
+ *  Outputs:
+ *      0 : Return header
+ *      1 : Result of function, 0 on success, otherwise error code
+ */
+void PreloadLibraryApplet(Service::Interface* self);
+
+/**
  * APT::StartLibraryApplet service function
  *  Inputs:
  *      0 : Command header [0x001E0084]
diff --git a/src/core/hle/service/apt/apt_a.cpp b/src/core/hle/service/apt/apt_a.cpp
index 88de339f9..22800c56f 100644
--- a/src/core/hle/service/apt/apt_a.cpp
+++ b/src/core/hle/service/apt/apt_a.cpp
@@ -21,6 +21,7 @@ const Interface::FunctionInfo FunctionTable[] = {
     {0x000D0080, ReceiveParameter,             "ReceiveParameter"},
     {0x000E0080, GlanceParameter,              "GlanceParameter"},
     {0x000F0100, CancelParameter,              "CancelParameter"},
+    {0x00160040, PreloadLibraryApplet,         "PreloadLibraryApplet"},
     {0x00180040, PrepareToStartLibraryApplet,  "PrepareToStartLibraryApplet"},
     {0x001E0084, StartLibraryApplet,           "StartLibraryApplet"},
     {0x003B0040, nullptr,                      "CancelLibraryApplet?"},
diff --git a/src/core/hle/service/apt/apt_s.cpp b/src/core/hle/service/apt/apt_s.cpp
index 396d1f04a..3ac6ff94f 100644
--- a/src/core/hle/service/apt/apt_s.cpp
+++ b/src/core/hle/service/apt/apt_s.cpp
@@ -32,9 +32,9 @@ const Interface::FunctionInfo FunctionTable[] = {
     {0x00130000, nullptr,               "GetPreparationState"},
     {0x00140040, nullptr,               "SetPreparationState"},
     {0x00150140, nullptr,               "PrepareToStartApplication"},
-    {0x00160040, nullptr,               "PreloadLibraryApplet"},
+    {0x00160040, PreloadLibraryApplet,  "PreloadLibraryApplet"},
     {0x00170040, nullptr,               "FinishPreloadingLibraryApplet"},
-    {0x00180040, nullptr,               "PrepareToStartLibraryApplet"},
+    {0x00180040, PrepareToStartLibraryApplet,"PrepareToStartLibraryApplet"},
     {0x00190040, nullptr,               "PrepareToStartSystemApplet"},
     {0x001A0000, nullptr,               "PrepareToStartNewestHomeMenu"},
     {0x001B00C4, nullptr,               "StartApplication"},
diff --git a/src/core/hle/service/apt/apt_u.cpp b/src/core/hle/service/apt/apt_u.cpp
index b724cd72b..146bfd595 100644
--- a/src/core/hle/service/apt/apt_u.cpp
+++ b/src/core/hle/service/apt/apt_u.cpp
@@ -33,7 +33,7 @@ const Interface::FunctionInfo FunctionTable[] = {
     {0x00130000, nullptr,                         "GetPreparationState"},
     {0x00140040, nullptr,                         "SetPreparationState"},
     {0x00150140, nullptr,                         "PrepareToStartApplication"},
-    {0x00160040, nullptr,                         "PreloadLibraryApplet"},
+    {0x00160040, PreloadLibraryApplet,            "PreloadLibraryApplet"},
     {0x00170040, nullptr,                         "FinishPreloadingLibraryApplet"},
     {0x00180040, PrepareToStartLibraryApplet,     "PrepareToStartLibraryApplet"},
     {0x00190040, nullptr,                         "PrepareToStartSystemApplet"},