[hle] Add missing service exports

src/SharpEmu.Libs/GameUpdate/GameUpdateExports.cs

@@ -0,0 +1,24 @@
+// Copyright (C) 2026 SharpEmu Emulator Project
+// SPDX-License-Identifier: GPL-2.0-or-later
+
+using System.Threading;
+using SharpEmu.HLE;
+
+namespace SharpEmu.Libs.GameUpdate;
+
+public static class GameUpdateExports
+{
+    private static int _initialized;
+
+    [SysAbiExport(
+        Nid = "YJtKLttI9fM",
+        ExportName = "sceGameUpdateInitialize",
+        Target = Generation.Gen4 | Generation.Gen5,
+        LibraryName = "libSceGameUpdate")]
+    public static int GameUpdateInitialize(CpuContext ctx)
+    {
+        Interlocked.Exchange(ref _initialized, 1);
+        ctx[CpuRegister.Rax] = 0;
+        return (int)OrbisGen2Result.ORBIS_GEN2_OK;
+    }
+}