DBGOSLAR

Provides a lock for the debug registers. The OS Lock also disables some debug exceptions and debug events.

Configuration

This register is present only when EL1 is capable of using AArch32. Otherwise, direct accesses to DBGOSLAR are UNDEFINED.

The OS Lock can also be locked or unlocked using the AArch64 System register OSLAR_EL1 and External register OSLAR_EL1.

Attributes

Field descriptions

OSLA, bits [31:0]

OS Lock Access. Writing the value 0xC5ACCE55 to the DBGOSLAR sets the OS Lock to 1. Writing any other value sets the OS Lock to 0.

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

Accessing DBGOSLAR

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

MCR{<c>}{<q>} <coproc>, {#}<opc1>, <Rt>, <CRn>, <CRm>{, {#}<opc2>}

coproc	opc1	CRn	CRm	opc2
0b1110	0b000	0b0001	0b0000	0b100

if PSTATE.EL == EL0 then UNDEFINED; elsif PSTATE.EL == EL1 then if Halted() && HaveEL(EL3) && EDSCR.SDD == '1' && boolean IMPLEMENTATION_DEFINED "EL3 trap priority when SDD == '1'" && !ELUsingAArch32(EL3) && MDCR_EL3.TDOSA == '1' then UNDEFINED; elsif EL2Enabled() && !ELUsingAArch32(EL2) && MDCR_EL2.<TDE,TDOSA> != '00' then AArch64.AArch32SystemAccessTrap(EL2, 0x05); elsif EL2Enabled() && ELUsingAArch32(EL2) && HDCR.<TDE,TDOSA> != '00' then AArch32.TakeHypTrapException(0x05); elsif HaveEL(EL3) && !ELUsingAArch32(EL3) && MDCR_EL3.TDOSA == '1' then if Halted() && EDSCR.SDD == '1' then UNDEFINED; else AArch64.AArch32SystemAccessTrap(EL3, 0x05); else DBGOSLAR = R[t]; elsif PSTATE.EL == EL2 then if Halted() && HaveEL(EL3) && EDSCR.SDD == '1' && boolean IMPLEMENTATION_DEFINED "EL3 trap priority when SDD == '1'" && !ELUsingAArch32(EL3) && MDCR_EL3.TDOSA == '1' then UNDEFINED; elsif HaveEL(EL3) && !ELUsingAArch32(EL3) && MDCR_EL3.TDOSA == '1' then if Halted() && EDSCR.SDD == '1' then UNDEFINED; else AArch64.AArch32SystemAccessTrap(EL3, 0x05); else DBGOSLAR = R[t]; elsif PSTATE.EL == EL3 then DBGOSLAR = R[t];

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OSLA