diff --git a/include/coreinit/filesystem.h b/include/coreinit/filesystem.h
index f679ecd7..8cc90222 100644
--- a/include/coreinit/filesystem.h
+++ b/include/coreinit/filesystem.h
@@ -35,7 +35,8 @@ typedef struct FSDirectoryEntry FSDirectoryEntry;
 typedef struct FSMessage FSMessage;
 typedef struct FSMountSource FSMountSource;
 typedef struct FSStat FSStat;
-typedef struct FSStateChangeInfo FSStateChangeInfo;
+typedef struct FSStateChangeParams FSStateChangeParams;
+typedef struct FSStateChangeParams FSStateChangeInfo;
 typedef struct FSVolumeInfo FSVolumeInfo;
 
 typedef enum FSErrorFlag
@@ -175,6 +176,7 @@ typedef enum FSMountSourceType
 } FSMountSourceType;
 
 typedef void(*FSAsyncCallback)(FSClient *, FSCmdBlock *, FSStatus, uint32_t);
+typedef void(*FSStateChangeCallback)(FSClient *, FSVolumeState, void *);
 
 struct FSClient
 {
@@ -214,11 +216,13 @@ WUT_CHECK_OFFSET(FSStat, 0x24, created);
 WUT_CHECK_OFFSET(FSStat, 0x2C, modified);
 WUT_CHECK_SIZE(FSStat, 0x64);
 
-struct FSStateChangeInfo
+struct FSStateChangeParams
 {
-   WUT_UNKNOWN_BYTES(0xC);
+   FSStateChangeCallback callback;
+   void *param;
+   uint32_t unk_0x08;
 };
-WUT_CHECK_SIZE(FSStateChangeInfo, 0xC);
+WUT_CHECK_SIZE(FSStateChangeParams, 0xC);
 
 struct FSMessage
 {
@@ -321,7 +325,7 @@ FSSetCmdPriority(FSCmdBlock *block,
 
 void
 FSSetStateChangeNotification(FSClient *client,
-                             FSStateChangeInfo *info);
+                             FSStateChangeParams *info);
 
 FSStatus
 FSGetCwd(FSClient *client,
@@ -690,6 +694,9 @@ FSRenameAsync(FSClient *client,
 FSVolumeState
 FSGetVolumeState(FSClient *client);
 
+FSError
+FSGetLastError(FSClient *client);
+
 FSError
 FSGetLastErrorCodeForViewer(FSClient *client);
 
diff --git a/include/coreinit/userconfig.h b/include/coreinit/userconfig.h
index ac73af18..358111b9 100644
--- a/include/coreinit/userconfig.h
+++ b/include/coreinit/userconfig.h
@@ -14,6 +14,7 @@ extern "C" {
 #endif
 
 typedef int32_t UCError;
+typedef int32_t UCHandle;
 typedef struct UCSysConfig UCSysConfig;
 typedef struct UCAsyncParams UCAsyncParams;
 
@@ -135,41 +136,41 @@ WUT_CHECK_OFFSET(UCAsyncParams, 0x14, settings);
 WUT_CHECK_OFFSET(UCAsyncParams, 0x18, vecs);
 WUT_CHECK_SIZE(UCAsyncParams, 0x1C);
 
-UCError
+UCHandle
 UCOpen();
 
 UCError
-UCClose(IOSHandle handle);
+UCClose(UCHandle handle);
 
 UCError
-UCDeleteSysConfig(int32_t handle,
+UCDeleteSysConfig(UCHandle handle,
                   uint32_t count,
                   UCSysConfig *settings);
 
 UCError
-UCDeleteSysConfigAsync(int32_t handle,
+UCDeleteSysConfigAsync(UCHandle handle,
                        uint32_t count,
                        UCSysConfig *settings,
                        UCAsyncParams *asyncParams);
 
 UCError
-UCReadSysConfig(int32_t handle,
+UCReadSysConfig(UCHandle handle,
                 uint32_t count,
                 UCSysConfig *settings);
 
 UCError
-UCReadSysConfigAsync(int32_t handle,
+UCReadSysConfigAsync(UCHandle handle,
                      uint32_t count,
                      UCSysConfig *settings,
                      UCAsyncParams *asyncParams);
 
 UCError
-UCWriteSysConfig(int32_t handle,
+UCWriteSysConfig(UCHandle handle,
                  uint32_t count,
                  UCSysConfig *settings);
 
 UCError
-UCWriteSysConfigAsync(int32_t handle,
+UCWriteSysConfigAsync(UCHandle handle,
                       uint32_t count,
                       UCSysConfig *settings,
                       UCAsyncParams *asyncParams);
diff --git a/include/nn/act/client_cpp.h b/include/nn/act/client_cpp.h
index 195894c3..e4f3e47a 100644
--- a/include/nn/act/client_cpp.h
+++ b/include/nn/act/client_cpp.h
@@ -109,7 +109,7 @@ GetParentalControlsSlotNo(void)
    asm("GetParentalControlSlotNo__Q2_2nn3actFv");
 
 nn::Result
-GetParentalControlsSlotNoEx(void)
+GetParentalControlsSlotNoEx(SlotNo *outSlotNo, SlotNo slot)
    asm("GetParentalControlSlotNoEx__Q2_2nn3actFPUcUc");
 
 PersistentId