source: ps2launchargs/source/uLaunchELF/hdl_info/main.c

#include <thbase.h> 
#include <thevent.h> 
#include <iomanX.h>
#include <stdio.h>
#include <loadcore.h>
#include <intrman.h>
#include <sys/stat.h>
#include <dev9.h>
#include <sifrpc.h>

#include "ps2_hdd.h"
#include "hdd.h"

int __attribute__((unused)) shutdown() { return 0; }

/* function declaration */
void rpcMainThread(void* param);
void *rpcCommandHandler(int command, void *Data, int Size);

static SifRpcDataQueue_t Rpc_Queue __attribute__((aligned(64)));
static SifRpcServerData_t Rpc_Server __attribute((aligned(64)));
static int Rpc_Buffer[1024] __attribute((aligned(64)));

/* Description: Module entry point */
int _start(int argc, char **argv)
{
 iop_thread_t param;
 int id;

 printf("Hdl Info: PS2 HDLoader Information Module v 0.1\n");
 printf("Hdl Info: 2006 Polo\n");

 printf("Hdl Info: IOP RPC Initialization.\n"); 
 /*create thread*/
 param.attr         = TH_C;
 param.thread     = rpcMainThread;
 param.priority = 40;
 param.stacksize    = 0x800;
 param.option      = 0;

 id = CreateThread(&param);
 if (id > 0) {
  StartThread(id,0);
  return 0;
 } else
  return 1;

 return MODULE_RESIDENT_END;
}

void rpcMainThread(void* param)
{
 SifInitRpc(0);
 SifSetRpcQueue(&Rpc_Queue, GetThreadId());
 SifRegisterRpc(&Rpc_Server, HDL_IRX, (void *) rpcCommandHandler, (u8 *) &Rpc_Buffer, 0, 0, &Rpc_Queue);
 SifRpcLoop(&Rpc_Queue);
}

void *rpcCommandHandler(int command, void *Data, int Size)
{
        switch (command) {
                case 4: //HDL Get Game Info
                        ((int *)Data)[0] = HdlGetGameInfo((char *)Data, (GameInfo *)(Data+4));
                        break;
        case 5: //HDL Rename Game
                ((int *)Data)[0] = HdlRenameGame((char*)Data);
                break;
        default:
                break;
 }
 return Data;
}