x86/x64 CPUID in C#

Question

Related to my other question, please help me debug \"An unhandled exception of type \'System.AccessViolationException\' occurred in Unknown Module. Additional information:

Answer 1

Thanks to @antiduh for his solution. I'd change the Invoke signature a little bit for better usability as follows, so you don't need to allocate an get the result as a set of registers

    // This is a modification to https://stackoverflow.com/a/7964376/725903
    [UnmanagedFunctionPointerAttribute(CallingConvention.Cdecl)]
    private delegate void CpuIDDelegate(int level, IntPtr ptr);

    [StructLayout(LayoutKind.Sequential, Size = 16)]
    public struct CpuIdResult
    {
        public int Eax;
        public int Ebx;
        public int Ecx;
        public int Edx;
    }

    public CpuIdResult Invoke(int level)
    {
        CpuIdResult result;
        IntPtr buffer = Marshal.AllocHGlobal(16);
        try
        {
            this.cpuIdDelg(level, buffer);
            result = (CpuIdResult)Marshal.PtrToStructure(buffer, typeof(CpuIdResult));
        }
        finally
        {
            Marshal.FreeHGlobal(buffer);
        }
        return result;
    }