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DBGOSDLR
AArch32 Registers
AArch64 Registers
AArch32 Instructions
AArch64 Instructions
Index by Encoding
External Registers
External Registers by Offset
Registers by Functional Group
Proprietary Notice

DBGOSDLR, Debug OS Double Lock Register

The DBGOSDLR characteristics are:

Purpose

Locks out the external debug interface.

Configuration

AArch32 System register DBGOSDLR bits [31:0] are architecturally mapped to AArch64 System register OSDLR_EL1[31:0].

This register is present only when FEAT_AA32EL1 is implemented. Otherwise, direct accesses to DBGOSDLR are UNDEFINED.

Attributes

DBGOSDLR is a 32-bit register.

Field descriptions

313029282726252423222120191817161514131211109876543210
RES0DLK

Bits [31:1]

Reserved, RES0.

DLK, bit [0]
When FEAT_DoubleLock is implemented:

OS Double Lock control bit.

DLKMeaning
0b0

OS Double Lock unlocked.

0b1

OS Double Lock locked, if DBGPRCR.CORENPDRQ (Core no powerdown request) bit is set to 0 and the PE is in Non-debug state.

The reset behavior of this field is:


Otherwise:

Reserved, RAZ/WI.

Accessing DBGOSDLR

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

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

coprocopc1CRnCRmopc2
0b11100b0000b00010b00110b100

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' && (IsFeatureImplemented(FEAT_DoubleLock) || ImpDefBool("Trapped by MDCR_EL3.TDOSA")) then Undefined(); elsif EL2Enabled() && IsFeatureImplemented(FEAT_AA64EL2) && !ELUsingAArch32(EL2) && MDCR_EL2().[TDE,TDOSA] != '00' && (IsFeatureImplemented(FEAT_DoubleLock) || ImpDefBool("Trapped by MDCR_EL2.TDOSA")) then AArch64_AArch32SystemAccessTrap(EL2, 0x05); elsif EL2Enabled() && IsFeatureImplemented(FEAT_AA32EL2) && ELUsingAArch32(EL2) && HDCR().[TDE,TDOSA] != '00' && (IsFeatureImplemented(FEAT_DoubleLock) || ImpDefBool("Trapped by HDCR.TDOSA")) then AArch32_TakeHypTrapException(0x05); elsif HaveEL(EL3) && IsFeatureImplemented(FEAT_AA64EL3) && !ELUsingAArch32(EL3) && MDCR_EL3().TDOSA == '1' && (IsFeatureImplemented(FEAT_DoubleLock) || ImpDefBool("Trapped by MDCR_EL3.TDOSA")) then if EL3SDDUndef() then Undefined(); else AArch64_AArch32SystemAccessTrap(EL3, 0x05); end; else R(t) = DBGOSDLR(); end; elsif PSTATE.EL == EL2 then if HaveEL(EL3) && EL3SDDUndefPriority() && IsFeatureImplemented(FEAT_AA64EL3) && !ELUsingAArch32(EL3) && MDCR_EL3().TDOSA == '1' && (IsFeatureImplemented(FEAT_DoubleLock) || ImpDefBool("Trapped by MDCR_EL3.TDOSA")) then Undefined(); elsif HaveEL(EL3) && IsFeatureImplemented(FEAT_AA64EL3) && !ELUsingAArch32(EL3) && MDCR_EL3().TDOSA == '1' && (IsFeatureImplemented(FEAT_DoubleLock) || ImpDefBool("Trapped by MDCR_EL3.TDOSA")) then if EL3SDDUndef() then Undefined(); else AArch64_AArch32SystemAccessTrap(EL3, 0x05); end; else R(t) = DBGOSDLR(); end; elsif PSTATE.EL == EL3 then R(t) = DBGOSDLR(); end;

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

coprocopc1CRnCRmopc2
0b11100b0000b00010b00110b100

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' && (IsFeatureImplemented(FEAT_DoubleLock) || ImpDefBool("Trapped by MDCR_EL3.TDOSA")) then Undefined(); elsif EL2Enabled() && IsFeatureImplemented(FEAT_AA64EL2) && !ELUsingAArch32(EL2) && MDCR_EL2().[TDE,TDOSA] != '00' && (IsFeatureImplemented(FEAT_DoubleLock) || ImpDefBool("Trapped by MDCR_EL2.TDOSA")) then AArch64_AArch32SystemAccessTrap(EL2, 0x05); elsif EL2Enabled() && IsFeatureImplemented(FEAT_AA32EL2) && ELUsingAArch32(EL2) && HDCR().[TDE,TDOSA] != '00' && (IsFeatureImplemented(FEAT_DoubleLock) || ImpDefBool("Trapped by HDCR.TDOSA")) then AArch32_TakeHypTrapException(0x05); elsif HaveEL(EL3) && IsFeatureImplemented(FEAT_AA64EL3) && !ELUsingAArch32(EL3) && MDCR_EL3().TDOSA == '1' && (IsFeatureImplemented(FEAT_DoubleLock) || ImpDefBool("Trapped by MDCR_EL3.TDOSA")) then if EL3SDDUndef() then Undefined(); else AArch64_AArch32SystemAccessTrap(EL3, 0x05); end; else DBGOSDLR() = R(t); end; elsif PSTATE.EL == EL2 then if HaveEL(EL3) && EL3SDDUndefPriority() && IsFeatureImplemented(FEAT_AA64EL3) && !ELUsingAArch32(EL3) && MDCR_EL3().TDOSA == '1' && (IsFeatureImplemented(FEAT_DoubleLock) || ImpDefBool("Trapped by MDCR_EL3.TDOSA")) then Undefined(); elsif HaveEL(EL3) && IsFeatureImplemented(FEAT_AA64EL3) && !ELUsingAArch32(EL3) && MDCR_EL3().TDOSA == '1' && (IsFeatureImplemented(FEAT_DoubleLock) || ImpDefBool("Trapped by MDCR_EL3.TDOSA")) then if EL3SDDUndef() then Undefined(); else AArch64_AArch32SystemAccessTrap(EL3, 0x05); end; else DBGOSDLR() = R(t); end; elsif PSTATE.EL == EL3 then DBGOSDLR() = R(t); end;

AArch32 Registers
AArch64 Registers
AArch32 Instructions
AArch64 Instructions
Index by Encoding
External Registers
External Registers by Offset
Registers by Functional Group
Proprietary Notice

2026-03-12 12:23:09, 2025-09_rel_asl1

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