Identifying CPU
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Introduction
Identifying an Intel-compatible x86 CPU is done in several steps :
- Check that we have a 32-bits 80386 minimum CPU.
- Check the presence of the CPUID instruction.
- If CPUID is supported, use the instruction to get CPU information and supported instructions.
- If CPUID is not supported, reset the CPU to get its signature.
- Calculate the operating frequency of the CPU by timing the execution of a sequence of instructions.
External documentation
Intel describes the complete process of CPU identification in Application Note 485.
AMD describes their specific CPUID implementation here