OSLAR_EL1 OS Lock Access Register OSLAR_EL1 is in the Core power domain Debug 0x300 OSLAR_EL1 When DoubleLockStatus(), or !IsCorePowered(), or (!AllowExternalDebugAccess(addrdesc) and FEAT_Debugv8p2 is implemented) ERROR When AllowExternalDebugAccess(addrdesc) and SoftwareLockStatus(addrdesc) WI When AllowExternalDebugAccess(addrdesc) and !SoftwareLockStatus(addrdesc) WO IMPDEF OSLAR_EL1 Architectural AArch64 31 0 31 0 31 0 31 0 Used to lock or unlock the OS Lock. Debug The OS Lock can also be locked or unlocked using DBGOSLAR. If FEAT_Debugv8p2 is not implemented, it is IMPLEMENTATION DEFINED whether external debug accesses to OSLAR_EL1 are ignored and return an error when AllowExternalDebugAccess() returns FALSE for the access. If FEAT_Debugv8p2 is implemented, external debug accesses to OSLAR_EL1 are ignored and return an error when AllowExternalDebugAccess() returns FALSE for the access. OSLAR_EL1 is a 32-bit register. 31 1 31:1 Reserved, RES0. OSLK 0 0 0 On writes to OSLAR_EL1, bit[0] is copied to the OS Lock. Use EDPRSR.OSLK to check the current status of the lock. 2026-03-26 20:27:25 2026-03_rel