TCR_A1
tcr &= ~(TCR_HD | TCR_HA | TCR_A1 | TCR_T0SZ_MASK);
ttbr_elx = (tcr & TCR_A1) ? TTBR1_EL1 : TTBR0_EL1;
ttbr_elx = (tcr & TCR_A1) ? TTBR1_EL2 : TTBR0_EL2;