Horizon: Implement arp:r and arp:w services (#5802)

* Horizon: Implement arp:r and arp:w services

* Fix formatting

* Remove HLE arp services

* Revert "Remove HLE arp services"

This reverts commit c576fcccadb963db56b96bacabd1c1ac7abfb1ab.

* Keep LibHac impl since it's used in bcat

* Addresses gdkchan's feedback

* ArpApi in PrepoIpcServer and remove LmApi

* Fix 2

* Fixes ArpApi init

* Fix encoding

* Update PrepoService.cs

* Fix prepo

5 files changed, 29 insertions, 6 deletions

diff --git a/src/Ryujinx.HLE/Loaders/Processes/Extensions/FileSystemExtensions.cs b/src/Ryujinx.HLE/Loaders/Processes/Extensions/FileSystemExtensions.cs
index 28f6fcff..3904d660 100644
--- a/src/Ryujinx.HLE/Loaders/Processes/Extensions/FileSystemExtensions.cs
+++ b/src/Ryujinx.HLE/Loaders/Processes/Extensions/FileSystemExtensions.cs
@@ -34,7 +34,7 @@ namespace Ryujinx.HLE.Loaders.Processes.Extensions
             return metaLoader;
         }
 
-        public static ProcessResult Load(this IFileSystem exeFs, Switch device, BlitStruct<ApplicationControlProperty> nacpData, MetaLoader metaLoader, bool isHomebrew = false)
+        public static ProcessResult Load(this IFileSystem exeFs, Switch device, BlitStruct<ApplicationControlProperty> nacpData, MetaLoader metaLoader, byte programIndex, bool isHomebrew = false)
         {
             ulong programId = metaLoader.GetProgramId();
 
@@ -119,6 +119,7 @@ namespace Ryujinx.HLE.Loaders.Processes.Extensions
                 true,
                 programName,
                 metaLoader.GetProgramId(),
+                programIndex,
                 null,
                 nsoExecutables);
 
diff --git a/src/Ryujinx.HLE/Loaders/Processes/Extensions/LocalFileSystemExtensions.cs b/src/Ryujinx.HLE/Loaders/Processes/Extensions/LocalFileSystemExtensions.cs
index 798a9261..39139ecc 100644
--- a/src/Ryujinx.HLE/Loaders/Processes/Extensions/LocalFileSystemExtensions.cs
+++ b/src/Ryujinx.HLE/Loaders/Processes/Extensions/LocalFileSystemExtensions.cs
@@ -26,7 +26,7 @@ namespace Ryujinx.HLE.Loaders.Processes
                 ProcessLoaderHelper.EnsureSaveData(device, new ApplicationId(programId), nacpData);
             }
 
-            ProcessResult processResult = exeFs.Load(device, nacpData, metaLoader);
+            ProcessResult processResult = exeFs.Load(device, nacpData, metaLoader, 0);
 
             // Load RomFS.
             if (!string.IsNullOrEmpty(romFsPath))
diff --git a/src/Ryujinx.HLE/Loaders/Processes/Extensions/NcaExtensions.cs b/src/Ryujinx.HLE/Loaders/Processes/Extensions/NcaExtensions.cs
index e369f4b0..e70fcb6f 100644
--- a/src/Ryujinx.HLE/Loaders/Processes/Extensions/NcaExtensions.cs
+++ b/src/Ryujinx.HLE/Loaders/Processes/Extensions/NcaExtensions.cs
@@ -61,7 +61,7 @@ namespace Ryujinx.HLE.Loaders.Processes.Extensions
 
             */
 
-            ProcessResult processResult = exeFs.Load(device, nacpData, metaLoader);
+            ProcessResult processResult = exeFs.Load(device, nacpData, metaLoader, (byte)nca.GetProgramIndex());
 
             // Load RomFS.
             if (romFs == null)
diff --git a/src/Ryujinx.HLE/Loaders/Processes/ProcessLoader.cs b/src/Ryujinx.HLE/Loaders/Processes/ProcessLoader.cs
index efeb9f61..e5056c89 100644
--- a/src/Ryujinx.HLE/Loaders/Processes/ProcessLoader.cs
+++ b/src/Ryujinx.HLE/Loaders/Processes/ProcessLoader.cs
@@ -77,7 +77,7 @@ namespace Ryujinx.HLE.Loaders.Processes
             if (processResult.ProcessId == 0)
             {
                 // This is not a normal NSP, it's actually a ExeFS as a NSP
-                processResult = partitionFileSystem.Load(_device, new BlitStruct<ApplicationControlProperty>(1), partitionFileSystem.GetNpdm(), true);
+                processResult = partitionFileSystem.Load(_device, new BlitStruct<ApplicationControlProperty>(1), partitionFileSystem.GetNpdm(), 0, true);
             }
 
             if (processResult.ProcessId != 0 && _processesByPid.TryAdd(processResult.ProcessId, processResult))
@@ -198,7 +198,7 @@ namespace Ryujinx.HLE.Loaders.Processes
             }
             else
             {
-                programName = System.IO.Path.GetFileNameWithoutExtension(path);
+                programName = Path.GetFileNameWithoutExtension(path);
 
                 executable = new NsoExecutable(new LocalStorage(path, FileAccess.Read), programName);
             }
@@ -215,6 +215,7 @@ namespace Ryujinx.HLE.Loaders.Processes
                                                                        allowCodeMemoryForJit: true,
                                                                        programName,
                                                                        programId,
+                                                                       0,
                                                                        null,
                                                                        executable);
 
diff --git a/src/Ryujinx.HLE/Loaders/Processes/ProcessLoaderHelper.cs b/src/Ryujinx.HLE/Loaders/Processes/ProcessLoaderHelper.cs
index a6a1d87e..fe2aaac6 100644
--- a/src/Ryujinx.HLE/Loaders/Processes/ProcessLoaderHelper.cs
+++ b/src/Ryujinx.HLE/Loaders/Processes/ProcessLoaderHelper.cs
@@ -19,6 +19,7 @@ using Ryujinx.HLE.HOS.Kernel.Process;
 using Ryujinx.HLE.Loaders.Executables;
 using Ryujinx.HLE.Loaders.Processes.Extensions;
 using Ryujinx.Horizon.Common;
+using Ryujinx.Horizon.Sdk.Arp;
 using System;
 using System.Linq;
 using System.Runtime.InteropServices;
@@ -229,6 +230,7 @@ namespace Ryujinx.HLE.Loaders.Processes
             bool allowCodeMemoryForJit,
             string name,
             ulong programId,
+            byte programIndex,
             byte[] arguments = null,
             params IExecutable[] executables)
         {
@@ -421,7 +423,7 @@ namespace Ryujinx.HLE.Loaders.Processes
             // Once everything is loaded, we can load cheats.
             device.Configuration.VirtualFileSystem.ModLoader.LoadCheats(programId, tamperInfo, device.TamperMachine);
 
-            return new ProcessResult(
+            ProcessResult processResult = new(
                 metaLoader,
                 applicationControlProperties,
                 diskCacheEnabled,
@@ -431,6 +433,25 @@ namespace Ryujinx.HLE.Loaders.Processes
                 meta.MainThreadPriority,
                 meta.MainThreadStackSize,
                 device.System.State.DesiredTitleLanguage);
+
+            // Register everything in arp service.
+            device.System.ServiceTable.ArpWriter.AcquireRegistrar(out IRegistrar registrar);
+            registrar.SetApplicationControlProperty(MemoryMarshal.Cast<byte, Horizon.Sdk.Ns.ApplicationControlProperty>(applicationControlProperties.ByteSpan)[0]);
+            // TODO: Handle Version and StorageId when it will be needed.
+            registrar.SetApplicationLaunchProperty(new ApplicationLaunchProperty()
+            {
+                ApplicationId = new Horizon.Sdk.Ncm.ApplicationId(programId),
+                Version = 0x00,
+                Storage = Horizon.Sdk.Ncm.StorageId.BuiltInUser,
+                PatchStorage = Horizon.Sdk.Ncm.StorageId.None,
+                ApplicationKind = ApplicationKind.Application,
+            });
+
+            device.System.ServiceTable.ArpReader.GetApplicationInstanceId(out ulong applicationInstanceId, process.Pid);
+            device.System.ServiceTable.ArpWriter.AcquireApplicationProcessPropertyUpdater(out IUpdater updater, applicationInstanceId);
+            updater.SetApplicationProcessProperty(process.Pid, new ApplicationProcessProperty() { ProgramIndex = programIndex });
+
+            return processResult;
         }
 
         public static Result LoadIntoMemory(KProcess process, IExecutable image, ulong baseAddress)