OSLAR_EL1, OS Lock Access Register

The OSLAR_EL1 characteristics are:

Purpose

Used to lock or unlock the OS Lock.

Configuration

AArch64 System register OSLAR_EL1 bits [31:0] are architecturally mapped to External register OSLAR_EL1[31:0].

The OS Lock can also be locked or unlocked using DBGOSLAR.

Attributes

OSLAR_EL1 is a 64-bit register.

Field descriptions

6362616059585756555453525150494847464544434241403938373635343332
313029282726252423222120191817161514131211109876543210
RES0
RES0OSLK

Bits [63:1]

Reserved, RES0.

OSLK, bit [0]

On writes to OSLAR_EL1, bit[0] is copied to the OS Lock.

Use OSLSR_EL1.OSLK to check the current status of the lock.

Accessing OSLAR_EL1

Accesses to this register use the following encodings in the System register encoding space:

MSR OSLAR_EL1, <Xt>

op0op1CRnCRmop2
0b100b0000b00010b00000b100

if PSTATE.EL == EL0 then UNDEFINED; elsif PSTATE.EL == EL1 then if HaveEL(EL3) && EL3SDDUndefPriority() && MDCR_EL3.TDOSA == '1' then UNDEFINED; elsif EL2Enabled() && IsFeatureImplemented(FEAT_FGT) && (!HaveEL(EL3) || SCR_EL3.FGTEn == '1') && HDFGWTR_EL2.OSLAR_EL1 == '1' then AArch64.SystemAccessTrap(EL2, 0x18); elsif EL2Enabled() && MDCR_EL2.<TDE,TDOSA> != '00' then AArch64.SystemAccessTrap(EL2, 0x18); elsif HaveEL(EL3) && MDCR_EL3.TDOSA == '1' then if EL3SDDUndef() then UNDEFINED; else AArch64.SystemAccessTrap(EL3, 0x18); else OSLAR_EL1 = X[t, 64]; elsif PSTATE.EL == EL2 then if HaveEL(EL3) && EL3SDDUndefPriority() && MDCR_EL3.TDOSA == '1' then UNDEFINED; elsif HaveEL(EL3) && MDCR_EL3.TDOSA == '1' then if EL3SDDUndef() then UNDEFINED; else AArch64.SystemAccessTrap(EL3, 0x18); else OSLAR_EL1 = X[t, 64]; elsif PSTATE.EL == EL3 then OSLAR_EL1 = X[t, 64];


26/03/2024 09:49; 67c0ae5282a7629ba0ea0ba7267b43cd4f7939f6

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