RunDllMain.cs

public override void Init(Machine machine)
{
    if (IsDll)
    {
        // Save DS
        var saveds = machine.ds;

        // Call Library entry point
        machine.di = hModule;
        machine.ds = DataSegment == null ? (ushort)0 : DataSegment.globalHandle;
        machine.cx = _neFile.Header.InitHeapSize;

        // Find entry point
        var ip = (ushort)(_neFile.Header.EntryPoint & 0xFFFF);
        var cs = _neFile.Segments[(int)((_neFile.Header.EntryPoint >> 16) - 1)].globalHandle;

        // Call it
        machine.FarCall(BitUtils.MakeDWord(ip, cs));
        
        // Success?
        if (machine.ax==0)
            throw new VirtualException("LibMain failed");

        // Restore DS
        machine.ds = saveds;
    }
}