diff --git a/game/overlord/jak3/basefile.h b/game/overlord/jak3/basefile.h
index 6d6a2fe6c34..da71cfaa4eb 100644
--- a/game/overlord/jak3/basefile.h
+++ b/game/overlord/jak3/basefile.h
@@ -1,5 +1,4 @@
-#ifndef BASEFILE_H_
-#define BASEFILE_H_
+#pragma once
 
 #include "game/overlord/jak3/iso_structs.h"
 #include "game/overlord/jak3/overlord.h"
@@ -18,4 +17,3 @@ class CBaseFile {
 };
 }  // namespace jak3
 
-#endif  // BASEFILE_H_
diff --git a/game/overlord/jak3/basefilesystem.h b/game/overlord/jak3/basefilesystem.h
index 2803428231f..18100f66e08 100644
--- a/game/overlord/jak3/basefilesystem.h
+++ b/game/overlord/jak3/basefilesystem.h
@@ -1,12 +1,11 @@
-#ifndef BASEFILESYSTEM_H_
-#define BASEFILESYSTEM_H_
+#pragma once
 
 #include "game/overlord/jak3/iso_structs.h"
 
 namespace jak3 {
 class CBaseFileSystem {
  public:
-  virtual void Init() = 0;
+  virtual int Init() = 0;
   virtual void PollDrive() = 0;
   virtual const ISOFileDef* Find(const char* name) = 0;
   virtual const ISOFileDef* FindIN(const char* name) = 0;
@@ -16,5 +15,3 @@ class CBaseFileSystem {
   virtual VagDirEntryJak3* FindVagFile(const char* name) = 0;
 };
 }  // namespace jak3
-
-#endif  // BASEFILESYSTEM_H_
diff --git a/game/overlord/jak3/iso_structs.h b/game/overlord/jak3/iso_structs.h
index 7af569aa763..8e3b997c286 100644
--- a/game/overlord/jak3/iso_structs.h
+++ b/game/overlord/jak3/iso_structs.h
@@ -1,5 +1,4 @@
-#ifndef ISO_STRUCTS_H_
-#define ISO_STRUCTS_H_
+#pragma once
 
 #include "common/common_types.h"
 
@@ -29,9 +28,5 @@ struct VagDirJak3 {
 
 struct VagDirEntry {};
 
-struct ISOBuffer {};
-
 struct ISOFileDef {};
 }  // namespace jak3
-
-#endif  // ISO_STRUCTS_H_
diff --git a/game/overlord/jak3/overlord.h b/game/overlord/jak3/overlord.h
index 8fae9fe51f2..15261e4a636 100644
--- a/game/overlord/jak3/overlord.h
+++ b/game/overlord/jak3/overlord.h
@@ -1,9 +1,15 @@
-#ifndef OVERLORD_H_
-#define OVERLORD_H_
+#pragma once
 
 #include <cstddef>
 
+#include "common/common_types.h"
+
 namespace jak3 {
+
+struct Vec3 {
+  s32 x, y, z;
+};
+
 enum class EIsoStatus { Unk };
 
 int start_overlord_wrapper(int argc, const char* const* argv, bool* signal);
@@ -14,5 +20,3 @@ void InitSound();
 
 int VBlank_Initialize();
 }  // namespace jak3
-
-#endif
diff --git a/game/overlord/jak3/pagemanager.h b/game/overlord/jak3/pagemanager.h
index 6c5e5283d1b..8ac7cc5a2df 100644
--- a/game/overlord/jak3/pagemanager.h
+++ b/game/overlord/jak3/pagemanager.h
@@ -1,5 +1,4 @@
-#ifndef PAGEMANAGER_H_
-#define PAGEMANAGER_H_
+#pragma once
 
 #include "common/common_types.h"
 
@@ -40,5 +39,3 @@ class CPageManager {
 };
 
 }  // namespace jak3
-
-#endif  // PAGEMANAGER_H_
diff --git a/game/overlord/jak3/ramdisk.cpp b/game/overlord/jak3/ramdisk.cpp
index e69de29bb2d..43a960253e9 100644
--- a/game/overlord/jak3/ramdisk.cpp
+++ b/game/overlord/jak3/ramdisk.cpp
@@ -0,0 +1,33 @@
+#include "ramdisk.h"
+
+#include "common/log/log.h"
+
+#include "game/sce/iop.h"
+
+namespace jak3 {
+using namespace iop;
+
+static u8 gRamDisk_RPCBUF[40];
+
+static void* RPC_Ramdisk(u32 fno, void* data, int size) {
+  lg::error("RPC_RAMDISK UNIMPLEMENTED");
+  return nullptr;
+}
+
+void InitRamdisk() {}
+
+u32 Thread_Server() {
+  sceSifQueueData dq;
+  sceSifServeData serve;
+
+  CpuDisableIntr();
+  sceSifInitRpc(0);
+  sceSifSetRpcQueue(&dq, GetThreadId());
+  sceSifRegisterRpc(&serve, 0xfab2, RPC_Ramdisk, gRamDisk_RPCBUF, nullptr, nullptr, &dq);
+  CpuEnableIntr();
+  sceSifRpcLoop(&dq);
+
+  return 0;
+}
+
+}  // namespace jak3
diff --git a/game/overlord/jak3/sbank.h b/game/overlord/jak3/sbank.h
index 310f890ef34..69a41942380 100644
--- a/game/overlord/jak3/sbank.h
+++ b/game/overlord/jak3/sbank.h
@@ -1,5 +1,4 @@
-#ifndef SBANK_H_
-#define SBANK_H_
+#pragma once
 
 #include "common/common_types.h"
 
@@ -18,5 +17,3 @@ struct SoundBankInfo {
 };
 void InitBanks();
 }  // namespace jak3
-
-#endif  // SBANK_H_
diff --git a/game/overlord/jak3/start.cpp b/game/overlord/jak3/start.cpp
index f53da86a3e8..4b1695b6d2b 100644
--- a/game/overlord/jak3/start.cpp
+++ b/game/overlord/jak3/start.cpp
@@ -2,13 +2,19 @@
 #include <cstring>
 
 #include "overlord.h"
+#include "ramdisk.h"
 #include "sbank.h"
 
+#include "game/overlord/jak3/srpc.h"
 #include "game/sce/iop.h"
 
 namespace jak3 {
 using namespace iop;
 
+int g_nServerThreadID;
+int g_nPlayerThreadID;
+int g_nLoaderThreadID;
+
 int start_overlord(int argc, const char* const* argp) {
   ThreadParam thp;
 
@@ -31,6 +37,52 @@ int start_overlord(int argc, const char* const* argp) {
   InitSound();
   VBlank_Initialize();
 
+  thp.attr = TH_C;
+  thp.option = 0;
+  thp.entry = Thread_Server;
+  thp.stackSize = 0x800;
+  thp.initPriority = 59;
+  g_nServerThreadID = CreateThread(&thp);
+  if (g_nServerThreadID < 0) {
+    Panic();
+    return 1;
+  }
+
+  thp.attr = TH_C;
+  thp.option = 0;
+  thp.entry = Thread_Player;
+  thp.stackSize = 0xb00;
+  thp.initPriority = 54;
+  g_nPlayerThreadID = CreateThread(&thp);
+  if (g_nPlayerThreadID < 0) {
+    Panic();
+    return 1;
+  }
+
+  thp.attr = TH_C;
+  thp.option = 0;
+  thp.entry = Thread_Loader;
+  thp.stackSize = 0x900;
+  thp.initPriority = 58;
+  g_nLoaderThreadID = CreateThread(&thp);
+  if (g_nPlayerThreadID < 0) {
+    Panic();
+    return 1;
+  }
+
+  //CDvdDriver::Initialize(&g_DvdDriver);
+  InitISOFS(argp[1], argp[2]);
+
+  StartThread(g_nServerThreadID, 0);
+  StartThread(g_nPlayerThreadID, 0);
+  StartThread(g_nLoaderThreadID, 0);
+
+  printf("======== overlrd2.irx post-startup ========\n");
+  // printf("      mem size: %lu\n", QueryMemSize());
+  // printf("total mem free: %lu\n", QueryTotalFreeMemSize());
+  // printf("  max mem free: %lu\n", QueryMaxFreeMemSize());
+  // printf("          used: %lu\n", QueryMemSize() - QueryTotalFreeMemSize());
+
   return 0;
 }
 
diff --git a/game/sce/iop.cpp b/game/sce/iop.cpp
index fff38a8f145..15a5f94d279 100644
--- a/game/sce/iop.cpp
+++ b/game/sce/iop.cpp
@@ -193,6 +193,12 @@ s32 SendMbx(s32 mbxid, void* sendmsg) {
   return iop->kernel.SendMbx(mbxid, sendmsg);
 }
 
+s32 ReceiveMbx(MsgPacket** recvmsg, int mbxid) {
+  ASSERT(false);
+  // TODO
+  return 0;
+}
+
 s32 PollMbx(MsgPacket** recvmsg, int mbxid) {
   return iop->kernel.PollMbx((void**)recvmsg, mbxid);
 }
diff --git a/game/sce/iop.h b/game/sce/iop.h
index 165e8f70744..b7426765665 100644
--- a/game/sce/iop.h
+++ b/game/sce/iop.h
@@ -131,6 +131,7 @@ int sceCdDiskReady(int mode);
 u32 sceSifSetDma(sceSifDmaData* sdd, int len);
 
 s32 SendMbx(int mbxid, void* sendmsg);
+s32 ReceiveMbx(MsgPacket** recvmsg, int mbxid);
 s32 PollMbx(MsgPacket** recvmsg, int mbxid);
 s32 PeekMbx(s32 mbx);
 s32 CreateMbx(MbxParam* param);