diff --git a/src/LibHac/FsSrv/FileSystemProxy.cs b/src/LibHac/FsSrv/FileSystemProxy.cs
index 3d2b26fb..ede552e8 100644
--- a/src/LibHac/FsSrv/FileSystemProxy.cs
+++ b/src/LibHac/FsSrv/FileSystemProxy.cs
@@ -37,7 +37,7 @@ namespace LibHac.FsSrv
 
         private ProgramRegistryService GetProgramRegistryService()
         {
-            return new ProgramRegistryService(FsProxyCore.Config.ProgramRegistryService, CurrentProcess);
+            return new ProgramRegistryService(FsProxyCore.Config.ProgramRegistryServiceImpl, CurrentProcess);
         }
 
         public Result OpenFileSystemWithId(out IFileSystem fileSystem, ref FsPath path, ulong id, FileSystemProxyType type)
@@ -649,6 +649,11 @@ namespace LibHac.FsSrv
             throw new NotImplementedException();
         }
 
+        public Result RegisterProgramIndexMapInfo(ReadOnlySpan<byte> programIndexMapInfoBuffer, int programCount)
+        {
+            return GetProgramRegistryService().RegisterProgramIndexMapInfo(programIndexMapInfoBuffer, programCount);
+        }
+
         public Result SetBisRootForHost(BisPartitionId partitionId, ref FsPath path)
         {
             throw new NotImplementedException();
@@ -1087,7 +1092,7 @@ namespace LibHac.FsSrv
 
         public Result GetProgramIndexForAccessLog(out int programIndex, out int programCount)
         {
-            throw new NotImplementedException();
+            return GetProgramRegistryService().GetProgramIndexForAccessLog(out programIndex, out programCount);
         }
 
         public Result OutputAccessLogToSdCard(U8Span logString)
@@ -1188,6 +1193,11 @@ namespace LibHac.FsSrv
             }
         }
 
+        private Result GetProgramInfo(out ProgramInfo programInfo)
+        {
+            return FsProxyCore.ProgramRegistry.GetProgramInfo(out programInfo, CurrentProcess);
+        }
+
         private static bool IsSystemSaveDataId(ulong id)
         {
             return (long)id < 0;
diff --git a/src/LibHac/FsSrv/FileSystemProxyConfiguration.cs b/src/LibHac/FsSrv/FileSystemProxyConfiguration.cs
index 3b57e3c6..ed15e0fd 100644
--- a/src/LibHac/FsSrv/FileSystemProxyConfiguration.cs
+++ b/src/LibHac/FsSrv/FileSystemProxyConfiguration.cs
@@ -5,6 +5,6 @@ namespace LibHac.FsSrv
     public class FileSystemProxyConfiguration
     {
         public FileSystemCreators FsCreatorInterfaces { get; set; }
-        public ProgramRegistryServiceImpl ProgramRegistryService { get; set; }
+        public ProgramRegistryServiceImpl ProgramRegistryServiceImpl { get; set; }
     }
 }
diff --git a/src/LibHac/FsSrv/FileSystemProxyCore.cs b/src/LibHac/FsSrv/FileSystemProxyCore.cs
index 69a6b4c3..e677bde6 100644
--- a/src/LibHac/FsSrv/FileSystemProxyCore.cs
+++ b/src/LibHac/FsSrv/FileSystemProxyCore.cs
@@ -35,7 +35,7 @@ namespace LibHac.FsSrv
         public FileSystemProxyCore(FileSystemProxyConfiguration config, ExternalKeySet externalKeys, IDeviceOperator deviceOperator)
         {
             Config = config;
-            ProgramRegistry = new ProgramRegistryImpl(Config.ProgramRegistryService);
+            ProgramRegistry = new ProgramRegistryImpl(Config.ProgramRegistryServiceImpl);
             ExternalKeys = externalKeys ?? new ExternalKeySet();
             DeviceOperator = deviceOperator;
         }
diff --git a/src/LibHac/FsSrv/FileSystemServer.cs b/src/LibHac/FsSrv/FileSystemServer.cs
index a42c172b..0a54e754 100644
--- a/src/LibHac/FsSrv/FileSystemServer.cs
+++ b/src/LibHac/FsSrv/FileSystemServer.cs
@@ -37,7 +37,7 @@ namespace LibHac.FsSrv
             var fspConfig = new FileSystemProxyConfiguration
             {
                 FsCreatorInterfaces = config.FsCreators,
-                ProgramRegistryService = new ProgramRegistryServiceImpl(this)
+                ProgramRegistryServiceImpl = new ProgramRegistryServiceImpl(this)
             };
 
             FsProxyCore = new FileSystemProxyCore(fspConfig, externalKeySet, config.DeviceOperator);
diff --git a/src/LibHac/FsSrv/IFileSystemProxy.cs b/src/LibHac/FsSrv/IFileSystemProxy.cs
index 94a63766..fe466db5 100644
--- a/src/LibHac/FsSrv/IFileSystemProxy.cs
+++ b/src/LibHac/FsSrv/IFileSystemProxy.cs
@@ -88,6 +88,7 @@ namespace LibHac.FsSrv
         Result SetSdCardAccessibility(bool isAccessible);
         Result IsSdCardAccessible(out bool isAccessible);
 
+        Result RegisterProgramIndexMapInfo(ReadOnlySpan<byte> programIndexMapInfoBuffer, int programCount);
         Result SetBisRootForHost(BisPartitionId partitionId, ref FsPath path);
         Result SetSaveDataSize(long saveDataSize, long saveDataJournalSize);
         Result SetSaveDataRootPath(ref FsPath path);
diff --git a/src/LibHac/FsSrv/Impl/ProgramRegistryManager.cs b/src/LibHac/FsSrv/Impl/ProgramRegistryManager.cs
index e7b37c78..df866f7e 100644
--- a/src/LibHac/FsSrv/Impl/ProgramRegistryManager.cs
+++ b/src/LibHac/FsSrv/Impl/ProgramRegistryManager.cs
@@ -37,7 +37,7 @@ namespace LibHac.FsSrv.Impl
         }
 
         /// <summary>
-        /// Registers a program with information about the program in the program registry.
+        /// Registers a program with information about that program in the program registry.
         /// </summary>
         /// <param name="processId">The process ID of the program.</param>
         /// <param name="programId">The <see cref="ProgramId"/> of the program.</param>
diff --git a/src/LibHac/FsSrv/ProgramIndexMapInfoManager.cs b/src/LibHac/FsSrv/ProgramIndexMapInfoManager.cs
index 2adb6a76..11f553a1 100644
--- a/src/LibHac/FsSrv/ProgramIndexMapInfoManager.cs
+++ b/src/LibHac/FsSrv/ProgramIndexMapInfoManager.cs
@@ -5,30 +5,36 @@ using LibHac.Ncm;
 
 namespace LibHac.FsSrv
 {
+    /// <summary>
+    /// Keeps track of the program IDs and program indexes of each program in a multi-program application.
+    /// </summary>
     public class ProgramIndexMapInfoManager
     {
         private LinkedList<ProgramIndexMapInfo> MapEntries { get; } = new LinkedList<ProgramIndexMapInfo>();
 
         /// <summary>
-        /// Clears any existing 
+        /// Unregisters any previously registered program index map info and registers the provided map info.
         /// </summary>
-        /// <param name="entries">The entries </param>
+        /// <param name="programIndexMapInfo">The program map info entries to register.</param>
         /// <returns><see cref="Result.Success"/>: The operation was successful.</returns>
-        public Result Reset(ReadOnlySpan<ProgramIndexMapInfo> entries)
+        public Result Reset(ReadOnlySpan<ProgramIndexMapInfo> programIndexMapInfo)
         {
             lock (MapEntries)
             {
                 ClearImpl();
 
-                for (int i = 0; i < entries.Length; i++)
+                for (int i = 0; i < programIndexMapInfo.Length; i++)
                 {
-                    MapEntries.AddLast(entries[i]);
+                    MapEntries.AddLast(programIndexMapInfo[i]);
                 }
 
                 return Result.Success;
             }
         }
 
+        /// <summary>
+        /// Unregisters all currently registered program index map info.
+        /// </summary>
         public void Clear()
         {
             lock (MapEntries)
@@ -37,6 +43,12 @@ namespace LibHac.FsSrv
             }
         }
 
+        /// <summary>
+        /// Gets the <see cref="ProgramIndexMapInfo"/> associated with the specified program ID.
+        /// </summary>
+        /// <param name="programId">The program ID of the map info to get.</param>
+        /// <returns>If the program ID was found, the <see cref="ProgramIndexMapInfo"/> associated
+        /// with that ID; otherwise, <see langword="null"/>.</returns>
         public ProgramIndexMapInfo? Get(ProgramId programId)
         {
             lock (MapEntries)
@@ -72,6 +84,10 @@ namespace LibHac.FsSrv
             }
         }
 
+        /// <summary>
+        /// Gets the number of currently registered programs,
+        /// </summary>
+        /// <returns>The number of registered programs.</returns>
         public int GetProgramCount()
         {
             lock (MapEntries)
diff --git a/src/LibHac/FsSrv/ProgramRegistryImpl.cs b/src/LibHac/FsSrv/ProgramRegistryImpl.cs
index d58eeb0e..649e6299 100644
--- a/src/LibHac/FsSrv/ProgramRegistryImpl.cs
+++ b/src/LibHac/FsSrv/ProgramRegistryImpl.cs
@@ -8,6 +8,8 @@ namespace LibHac.FsSrv
     internal class ProgramRegistryImpl
     {
         private ulong _processId;
+
+        // Note: FS keeps this object as a global variable
         private readonly ProgramRegistryServiceImpl _registryService;
 
         public ProgramRegistryImpl(ProgramRegistryServiceImpl registryService)
@@ -22,17 +24,10 @@ namespace LibHac.FsSrv
             _registryService = registryService;
         }
 
-        /// <summary>
-        /// Registers a program with information about the program in the program registry.
-        /// </summary>
-        /// <param name="processId">The process ID of the program.</param>
-        /// <param name="programId">The <see cref="ProgramId"/> of the program.</param>
-        /// <param name="storageId">The <see cref="StorageId"/> where the program is located.</param>
-        /// <param name="accessControlData">The FS access control data header located in the program's ACI.</param>
-        /// <param name="accessControlDescriptor">The FS access control descriptor located in the program's ACID.</param>
         /// <returns><see cref="Result.Success"/>: The operation was successful.<br/>
         /// <see cref="ResultFs.InvalidArgument"/>: The process ID is already registered.<br/>
         /// <see cref="ResultFs.PermissionDenied"/>: Insufficient permissions.</returns>
+        /// <inheritdoc cref="ProgramRegistryManager.RegisterProgram"/>
         public Result RegisterProgram(ulong processId, ProgramId programId, StorageId storageId,
             ReadOnlySpan<byte> accessControlData, ReadOnlySpan<byte> accessControlDescriptor)
         {
@@ -43,13 +38,10 @@ namespace LibHac.FsSrv
                 accessControlDescriptor);
         }
 
-        /// <summary>
-        /// Unregisters the program with the specified process ID.
-        /// </summary>
-        /// <param name="processId">The process ID of the program to unregister.</param>
         /// <returns><see cref="Result.Success"/>: The operation was successful.<br/>
         /// <see cref="ResultFs.InvalidArgument"/>: The process ID is not registered.<br/>
         /// <see cref="ResultFs.PermissionDenied"/>: Insufficient permissions.</returns>
+        /// <inheritdoc cref="ProgramRegistryManager.UnregisterProgram" />
         public Result UnregisterProgram(ulong processId)
         {
             if (!ProgramInfo.IsInitialProgram(_processId))
@@ -58,27 +50,13 @@ namespace LibHac.FsSrv
             return _registryService.UnregisterProgram(processId);
         }
 
-        /// <summary>
-        /// Gets the <see cref="ProgramInfo"/> associated with the specified process ID.
-        /// </summary>
-        /// <param name="programInfo">If the method returns successfully, contains the <see cref="ProgramInfo"/>
-        /// associated with the specified process ID.</param>
-        /// <param name="processId">The process ID of the <see cref="ProgramInfo"/> to get.</param>
-        /// <returns><see cref="Result.Success"/>: The operation was successful.<br/>
-        /// <see cref="ResultFs.TargetProgramNotFound"/>: The <see cref="ProgramInfo"/> was not found.</returns>
+        /// <inheritdoc cref="ProgramRegistryManager.GetProgramInfo"/>
         public Result GetProgramInfo(out ProgramInfo programInfo, ulong processId)
         {
             return _registryService.GetProgramInfo(out programInfo, processId);
         }
 
-        /// <summary>
-        /// Gets the <see cref="ProgramInfo"/> associated with the specified program ID.
-        /// </summary>
-        /// <param name="programInfo">If the method returns successfully, contains the <see cref="ProgramInfo"/>
-        /// associated with the specified program ID.</param>
-        /// <param name="programId">The program ID of the <see cref="ProgramInfo"/> to get.</param>
-        /// <returns><see cref="Result.Success"/>: The operation was successful.<br/>
-        /// <see cref="ResultFs.TargetProgramNotFound"/>: The <see cref="ProgramInfo"/> was not found.</returns>
+        /// <inheritdoc cref="ProgramRegistryManager.GetProgramInfoByProgramId"/>
         public Result GetProgramInfoByProgramId(out ProgramInfo programInfo, ulong programId)
         {
             return _registryService.GetProgramInfoByProgramId(out programInfo, programId);
diff --git a/src/LibHac/FsSrv/ProgramRegistryService.cs b/src/LibHac/FsSrv/ProgramRegistryService.cs
index 03825f4e..3cc9460b 100644
--- a/src/LibHac/FsSrv/ProgramRegistryService.cs
+++ b/src/LibHac/FsSrv/ProgramRegistryService.cs
@@ -1,4 +1,10 @@
-namespace LibHac.FsSrv
+using System;
+using System.Runtime.CompilerServices;
+using System.Runtime.InteropServices;
+using LibHac.Fs;
+using LibHac.FsSrv.Impl;
+
+namespace LibHac.FsSrv
 {
     internal readonly struct ProgramRegistryService
     {
@@ -10,5 +16,78 @@
             ServiceImpl = serviceImpl;
             ProcessId = processId;
         }
+
+        /// <summary>
+        /// Unregisters any previously registered program index map info and registers the provided map info.
+        /// </summary>
+        /// <param name="programIndexMapInfo">A buffer containing the program map info to register.</param>
+        /// <param name="programCount">The number of programs to register. The provided buffer must be
+        /// large enough to hold this many <see cref="ProgramIndexMapInfo"/> entries.</param>
+        /// <returns><see cref="Result.Success"/>: The operation was successful.<br/>
+        /// <see cref="ResultFs.PermissionDenied"/>: Insufficient permissions.<br/>
+        /// <see cref="ResultFs.InvalidSize"/>: The buffer was too small to hold the specified
+        /// number of <see cref="ProgramIndexMapInfo"/> entries.</returns>
+        public Result RegisterProgramIndexMapInfo(ReadOnlySpan<byte> programIndexMapInfo, int programCount)
+        {
+            // Verify the caller's permissions
+            Result rc = GetProgramInfo(out ProgramInfo programInfo, ProcessId);
+            if (rc.IsFailure()) return rc;
+
+            if (!programInfo.AccessControl.CanCall(OperationType.RegisterProgramIndexMapInfo))
+                return ResultFs.PermissionDenied.Log();
+
+            // Return early if the program count is 0 so we leave any previously
+            // registered entries as they were
+            if (programCount == 0)
+                return Result.Success;
+
+            // Verify that the provided buffer is large enough to hold "programCount" entries
+            ReadOnlySpan<ProgramIndexMapInfo>
+                mapInfo = MemoryMarshal.Cast<byte, ProgramIndexMapInfo>(programIndexMapInfo);
+
+            if (mapInfo.Length < programCount)
+                return ResultFs.InvalidSize.Log();
+
+            // Register the map info
+            return ServiceImpl.RegisterProgramIndexMapInfo(mapInfo.Slice(0, programCount));
+        }
+
+        /// <summary>
+        /// Gets the multi-program index of the calling process and the number of programs
+        /// in the current application.
+        /// </summary>
+        /// <param name="programIndex">When this method returns successfully, contains the
+        /// program index of the calling process.</param>
+        /// <param name="programCount">When this method returns successfully, contains the
+        /// number of programs in the current application.</param>
+        /// <returns><see cref="Result.Success"/>: The operation was successful.<br/>
+        /// <see cref="ResultFs.TargetProgramNotFound"/>: The calling program was not found
+        /// in the program registry. Something's wrong with Loader if this happens.</returns>
+        public Result GetProgramIndexForAccessLog(out int programIndex, out int programCount)
+        {
+            Unsafe.SkipInit(out programIndex);
+            Unsafe.SkipInit(out programCount);
+
+            // No permissions are needed to call this method
+            Result rc = GetProgramInfo(out ProgramInfo programInfo, ProcessId);
+            if (rc.IsFailure()) return rc;
+
+            // Try to get map info for this process
+            ProgramIndexMapInfo? mapInfo = ServiceImpl.GetProgramIndexMapInfo(programInfo.ProgramId);
+
+            // Set the output program index if map info was found
+            programIndex = mapInfo?.ProgramIndex ?? 0;
+
+            // Set the number of programs in the current application
+            programCount = ServiceImpl.GetProgramIndexMapInfoCount();
+
+            return Result.Success;
+        }
+
+        /// <inheritdoc cref="ProgramRegistryServiceImpl.GetProgramInfo"/>
+        private Result GetProgramInfo(out ProgramInfo programInfo, ulong processId)
+        {
+            return ServiceImpl.GetProgramInfo(out programInfo, processId);
+        }
     }
 }
diff --git a/src/LibHac/FsSrv/ProgramRegistryServiceImpl.cs b/src/LibHac/FsSrv/ProgramRegistryServiceImpl.cs
index 90f5cfb2..04ac011e 100644
--- a/src/LibHac/FsSrv/ProgramRegistryServiceImpl.cs
+++ b/src/LibHac/FsSrv/ProgramRegistryServiceImpl.cs
@@ -5,6 +5,9 @@ using LibHac.Ncm;
 
 namespace LibHac.FsSrv
 {
+    /// <summary>
+    /// Manages the main program registry and the multi-program registry.
+    /// </summary>
     public class ProgramRegistryServiceImpl
     {
         private ProgramRegistryManager RegistryManager { get; }
@@ -16,16 +19,7 @@ namespace LibHac.FsSrv
             ProgramIndexManager = new ProgramIndexMapInfoManager();
         }
 
-        /// <summary>
-        /// Registers a program with information about the program in the program registry.
-        /// </summary>
-        /// <param name="processId">The process ID of the program.</param>
-        /// <param name="programId">The <see cref="ProgramId"/> of the program.</param>
-        /// <param name="storageId">The <see cref="StorageId"/> where the program is located.</param>
-        /// <param name="accessControlData">The FS access control data header located in the program's ACI.</param>
-        /// <param name="accessControlDescriptor">The FS access control descriptor located in the program's ACID.</param>
-        /// <returns><see cref="Result.Success"/>: The operation was successful.<br/>
-        /// <see cref="ResultFs.InvalidArgument"/>: The process ID is already registered.</returns>
+        /// <inheritdoc cref="ProgramRegistryManager.RegisterProgram"/>
         public Result RegisterProgram(ulong processId, ProgramId programId, StorageId storageId,
             ReadOnlySpan<byte> accessControlData, ReadOnlySpan<byte> accessControlDescriptor)
         {
@@ -33,54 +27,49 @@ namespace LibHac.FsSrv
                 accessControlDescriptor);
         }
 
-        /// <summary>
-        /// Unregisters the program with the specified process ID.
-        /// </summary>
-        /// <param name="processId">The process ID of the program to unregister.</param>
-        /// <returns><see cref="Result.Success"/>: The operation was successful.<br/>
-        /// <see cref="ResultFs.InvalidArgument"/>: The process ID is not registered.</returns>
+        /// <inheritdoc cref="ProgramRegistryManager.UnregisterProgram" />
         public Result UnregisterProgram(ulong processId)
         {
             return RegistryManager.UnregisterProgram(processId);
         }
 
-        /// <summary>
-        /// Gets the <see cref="ProgramInfo"/> associated with the specified process ID.
-        /// </summary>
-        /// <param name="programInfo">If the method returns successfully, contains the <see cref="ProgramInfo"/>
-        /// associated with the specified process ID.</param>
-        /// <param name="processId">The process ID of the <see cref="ProgramInfo"/> to get.</param>
-        /// <returns><see cref="Result.Success"/>: The operation was successful.<br/>
-        /// <see cref="ResultFs.TargetProgramNotFound"/>: The <see cref="ProgramInfo"/> was not found.</returns>
+        /// <inheritdoc cref="ProgramRegistryManager.GetProgramInfo"/>
         public Result GetProgramInfo(out ProgramInfo programInfo, ulong processId)
         {
             return RegistryManager.GetProgramInfo(out programInfo, processId);
         }
 
-        /// <summary>
-        /// Gets the <see cref="ProgramInfo"/> associated with the specified program ID.
-        /// </summary>
-        /// <param name="programInfo">If the method returns successfully, contains the <see cref="ProgramInfo"/>
-        /// associated with the specified program ID.</param>
-        /// <param name="programId">The program ID of the <see cref="ProgramInfo"/> to get.</param>
-        /// <returns><see cref="Result.Success"/>: The operation was successful.<br/>
-        /// <see cref="ResultFs.TargetProgramNotFound"/>: The <see cref="ProgramInfo"/> was not found.</returns>
+        /// <inheritdoc cref="ProgramRegistryManager.GetProgramInfoByProgramId"/>
         public Result GetProgramInfoByProgramId(out ProgramInfo programInfo, ulong programId)
         {
             return RegistryManager.GetProgramInfoByProgramId(out programInfo, programId);
         }
 
-        /// <summary>
-        /// Gets the <see cref="ProgramId"/> of the program with index <paramref name="programIndex"/> in the
-        /// multi-program app <paramref name="programId"/> is part of.
-        /// </summary>
-        /// <param name="programId">A program ID in the multi-program app to query.</param>
-        /// <param name="programIndex">The index of the program to get.</param>
-        /// <returns>If the program exists, the ID of the program with the specified index,
-        /// otherwise <see cref="ProgramId.InvalidId"/></returns>
+        /// <inheritdoc cref="ProgramIndexMapInfoManager.GetProgramId"/>
         public ProgramId GetProgramId(ProgramId programId, byte programIndex)
         {
             return ProgramIndexManager.GetProgramId(programId, programIndex);
         }
+
+        /// <inheritdoc cref="ProgramIndexMapInfoManager.Get"/>
+        public ProgramIndexMapInfo? GetProgramIndexMapInfo(ProgramId programId)
+        {
+            return ProgramIndexManager.Get(programId);
+        }
+
+        /// <summary>
+        /// Gets the number of programs in the currently registered application.
+        /// </summary>
+        /// <returns>The number of programs.</returns>
+        public int GetProgramIndexMapInfoCount()
+        {
+            return ProgramIndexManager.GetProgramCount();
+        }
+
+        /// <inheritdoc cref="ProgramIndexMapInfoManager.Reset"/>
+        public Result RegisterProgramIndexMapInfo(ReadOnlySpan<ProgramIndexMapInfo> programIndexMapInfo)
+        {
+            return ProgramIndexManager.Reset(programIndexMapInfo);
+        }
     }
 }