Get your Pentium IV CPU ID (or serial number)

[vortex]

Get your Pentium IV CPU ID (or serial number)

bjarne

C、C++ (2003-05-06 20:06:09)

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Sometime, in a encryption program or a software liscencing program, we need to get the unique ID of a machine. P4 CPU ID provides this facility. But there is no way for you to get this ID (or serial number) by calling standard C function or Win32 API function. The only way is to use an Intel instruction called: CPUID. Here is the function I always use in my own program, it compiles and works fine in Visual C++. So, if you feel it is good for you, just copy the function source code and use it.

#include <stdio.h>

struct cpuid_t
{
    unsigned long id0;
    unsigned long id1;
    unsigned long id2;
    unsigned long id3;
};

inline cpuid_t getCPUID(unsigned long func_idx)
{
    cpuid_t id;
    __asm{
        mov eax, func_idx
        cpuid
        mov id.id0, eax
        mov id.id1, ebx
        mov id.id2, ecx
        mov id.id3, edx
    }
    return id;
}

void main()
{
    for(int j=0; j<2; j++)
    {
        for(int i=0; i<4; i++)
        {
            unsigned long k=i+(j?0x80000000:0);
            cpuid_t id=getCPUID(k);
            printf("your CPU id is: [0x%xH]%x-%x-%x-%x\n", k, id.id0, id.id1, id.id2, id.id3);
        }
    }
}

Here the func_idx is the function index. Different index will give you different id content. For detail, please download and read the Intel IA32 intruction set reference from www.intel.com.

Here, I want to emphasize that I don't recommend heavy use of assembly code directly, but for some of the special jobs you need to do, you probably must use some embedded assembly code in your C/C++ code.

I will talk about this more later. Enjoy!