CPUID_STEPPING
if ((model == 0x04 && (cpu_id & CPUID_STEPPING) == 0) ||
(model == 0x05 && (cpu_id & CPUID_STEPPING) <= 1))
(model == 0x04 && (cpuid & CPUID_STEPPING) >= 3))
cpu_stepping = cpu_id & CPUID_STEPPING;
kprintf(" Stepping=%u", cpu_id & CPUID_STEPPING);