The CPUID instruction provides processor feature capabilities and configuration information. This information
is accessed by (1) loading the function number into EAX, (2) executing the CPUID instruction, and (3) reading
the results stored in EAX, EBX, ECX, and EDX. In the following sections, the phrase CPUID function X or
CPUID FnX refers to the CPUID instruction when EAX is preloaded with X.