CNTPOFF_EL2 Counter-timer Physical Offset Register when FEAT_ECV_POFF is implemented and FEAT_AA64 is implemented Holds the 64-bit physical offset. This is the offset for the AArch64 EL1 physical timer and counter when Enhanced Counter Virtualization is enabled. Timer The physical offset applies to: Direct reads of CNTPCT_EL0 from EL0 or EL1. Indirect reads of the physical counter by the EL1 physical timer. See 'The Generic Timer in AArch64 state'. Indirect reads of the physical counter for timestamps generated by profiling logic. See 'The Statistical Profiling Extension' and 'AArch64 Self-hosted Trace'. The physical offset only applies under conditions described by the relevant sections. If EL2 is not implemented, this register is RES0 from EL3. CNTPOFF_EL2 is a 64-bit register. PO Physical offset 63 0 63:0 Physical offset. AU MRS <Xt>, CNTPOFF_EL2 if !(IsFeatureImplemented(FEAT_ECV_POFF) && IsFeatureImplemented(FEAT_AA64)) then Undefined(); elsif PSTATE.EL == EL0 then Undefined(); elsif PSTATE.EL == EL1 then if EffectiveHCR_EL2_NVx() IN {'1x1'} then X{64}(t) = NVMem(0x1A8); elsif EffectiveHCR_EL2_NVx() IN {'xx1'} then AArch64_SystemAccessTrap(EL2, 0x18); else Undefined(); end; elsif PSTATE.EL == EL2 then if HaveEL(EL3) && EL3SDDUndefPriority() && SCR_EL3().ECVEn == '0' then Undefined(); elsif HaveEL(EL3) && SCR_EL3().ECVEn == '0' then if EL3SDDUndef() then Undefined(); else AArch64_SystemAccessTrap(EL3, 0x18); end; else X{64}(t) = CNTPOFF_EL2(); end; elsif PSTATE.EL == EL3 then X{64}(t) = CNTPOFF_EL2(); end; MSR CNTPOFF_EL2, <Xt> if !(IsFeatureImplemented(FEAT_ECV_POFF) && IsFeatureImplemented(FEAT_AA64)) then Undefined(); elsif PSTATE.EL == EL0 then Undefined(); elsif PSTATE.EL == EL1 then if EffectiveHCR_EL2_NVx() IN {'1x1'} then NVMem(0x1A8) = X{64}(t); elsif EffectiveHCR_EL2_NVx() IN {'xx1'} then AArch64_SystemAccessTrap(EL2, 0x18); else Undefined(); end; elsif PSTATE.EL == EL2 then if HaveEL(EL3) && EL3SDDUndefPriority() && SCR_EL3().ECVEn == '0' then Undefined(); elsif HaveEL(EL3) && SCR_EL3().ECVEn == '0' then if EL3SDDUndef() then Undefined(); else AArch64_SystemAccessTrap(EL3, 0x18); end; else CNTPOFF_EL2() = X{64}(t); end; elsif PSTATE.EL == EL3 then CNTPOFF_EL2() = X{64}(t); end; 2026-03-26 20:27:25 2026-03_rel