Mupen64Plus-Core | OpenEmu Core plugin with Mupen64Plus to support N64

I'm using Mupen64Plus and the included m64p_test_rom.v64 file.

I'm using C# to talk to the mupen64plus.dll API which is written in C.

Problem

I'm trying to use its API command M64CMD_ROM_GET_HEADER to get the ROM Header from m64p_test_rom.v64, which contains properties like Name, Manufacturer ID, Country code. It looks like the command stores the data in a struct.

The problem is that when the API command is called to populate the struct, the variables remain null, it does not populate it with new values.

I'm using this C# API code from BizHawk to talk to mupen64plus.dll.

Commands

Mupen64Plus v2.0 Core Front-End Wiki

1. CoreDoCommand(m64p_command Command, int ParamInt, void *ParamPtr)

   Command Enumerated type specifying which command should be executed.

   ParamInt: An integer value which may be used as an input to the command.
   ParamPtr: A pointer which may be used as an input to the command.

2. M64CMD_ROM_GET_HEADER

   This will retrieve the header data of the currently open ROM. A ROM image must be open.

   ParamInt: Pointer to a rom_header struct to receive the data.
   ParamPtr: The size in bytes of the rom_header struct.

In my C# project I created a new struct to match the one in the Mupen64Plus's C source code. I'm not sure if I have converted it from C to C# correctly.

Mupen64Plus C m64p_types.h