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 AArch32 System register DBGOSLAR[31:0] .

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

Attributes

OSLAR_EL1 is a 64-bit register.

Field descriptions

The OSLAR_EL1 bit assignments are:

6362616059585756555453525150494847464544434241403938373635343332
RES0
RES0OSLK
313029282726252423222120191817161514131211109876543210

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 the OSLAR_EL1

Accesses to this register use the following encodings:

MSR OSLAR_EL1, <Xt>

op0op1CRnCRmop2
0b100b0000b00010b00000b100

if PSTATE.EL == EL0 then UNDEFINED; elsif PSTATE.EL == EL1 then if EL2Enabled() && !ELUsingAArch32(EL2) && MDCR_EL2.<TDE,TDOSA> != '00' then AArch64.SystemAccessTrap(EL2, 0x18); elsif HaveEL(EL3) && !ELUsingAArch32(EL3) && MDCR_EL3.TDOSA == '1' then AArch64.SystemAccessTrap(EL3, 0x18); else OSLAR_EL1 = X[t]; elsif PSTATE.EL == EL2 then if HaveEL(EL3) && !ELUsingAArch32(EL3) && MDCR_EL3.TDOSA == '1' then AArch64.SystemAccessTrap(EL3, 0x18); else OSLAR_EL1 = X[t]; elsif PSTATE.EL == EL3 then OSLAR_EL1 = X[t];




27/03/2019 21:59; e5e4db499bf9867a4b93324c4dbac985d3da9376

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