DBGOSLSR Debug OS Lock Status Register when FEAT_AA32EL1 is implemented OSLSR_EL1 Architectural AArch64 31 0 31 0 31 0 31 0 Provides status information for the OS Lock. Debug The OS Lock status is also visible in the external debug interface through EDPRSR. DBGOSLSR is a 32-bit register. 31 4 31:4 Reserved, RES0. OSLM 3 3 3, 0 OS Lock model implemented. Identifies the form of OS save and restore mechanism implemented. All other values are reserved. In an Armv8 implementation the value 0b00 is not permitted. The OSLM field is split as follows: OSLM[1] is DBGOSLSR[3]. OSLM[0] is DBGOSLSR[0]. 3 3 0 0 OSLM 0b00 OS Lock not implemented. 0b10 OS Lock implemented. RO nTT 2 2 2 Not 32-bit access. This bit is always RAZ. It indicates that a 32-bit access is needed to write the key to the OS Lock Access Register. This field has an IMPLEMENTATION DEFINED value. RO OSLK 1 1 1 OS Lock Status. The OS Lock is locked and unlocked by writing to the OS Lock Access Register. 0b0 OS Lock unlocked. 0b1 OS Lock locked. '1' OSLM[0] 0 0 3, 0 This field is bit[0] of OSLM[1:0]. See OSLM[1] for the field description. MRC{<c>}{<q>} <coproc>, {#}<opc1>, <Rt>, <CRn>, <CRm>{, {#}<opc2>} if !IsFeatureImplemented(FEAT_AA32EL1) then Undefined(); elsif PSTATE.EL == EL0 then Undefined(); elsif PSTATE.EL == EL1 then if HaveEL(EL3) && EL3SDDUndefPriority() && IsFeatureImplemented(FEAT_AA64EL3) && !ELUsingAArch32(EL3) && MDCR_EL3().TDOSA == '1' then Undefined(); elsif EL2Enabled() && IsFeatureImplemented(FEAT_AA64EL2) && !ELUsingAArch32(EL2) && MDCR_EL2().[TDE,TDOSA] != '00' then AArch64_AArch32SystemAccessTrap(EL2, 0x05); elsif EL2Enabled() && IsFeatureImplemented(FEAT_AA32EL2) && ELUsingAArch32(EL2) && HDCR().[TDE,TDOSA] != '00' then AArch32_TakeHypTrapException(0x05); elsif HaveEL(EL3) && IsFeatureImplemented(FEAT_AA64EL3) && !ELUsingAArch32(EL3) && MDCR_EL3().TDOSA == '1' then if EL3SDDUndef() then Undefined(); else AArch64_AArch32SystemAccessTrap(EL3, 0x05); end; else R(t) = DBGOSLSR(); end; elsif PSTATE.EL == EL2 then if HaveEL(EL3) && EL3SDDUndefPriority() && IsFeatureImplemented(FEAT_AA64EL3) && !ELUsingAArch32(EL3) && MDCR_EL3().TDOSA == '1' then Undefined(); elsif HaveEL(EL3) && IsFeatureImplemented(FEAT_AA64EL3) && !ELUsingAArch32(EL3) && MDCR_EL3().TDOSA == '1' then if EL3SDDUndef() then Undefined(); else AArch64_AArch32SystemAccessTrap(EL3, 0x05); end; else R(t) = DBGOSLSR(); end; elsif PSTATE.EL == EL3 then R(t) = DBGOSLSR(); end; 2026-03-26 20:27:25 2026-03_rel