ID_AA64PFR0_EL0_MASK
cpu_id_aa64pfr0 &= ~ID_AA64PFR0_EL0_MASK;
id &= ~ID_AA64PFR0_EL0_MASK;
#define ID_AA64PFR0_EL0(x) ((x) & ID_AA64PFR0_EL0_MASK)