DBGOSECCR Debug OS Lock Exception Catch Control Register when FEAT_AA32EL1 is implemented OSECCR_EL1 Architectural AArch64 31 0 31 0 31 0 31 0 EDECCR Architectural External 31 0 31 0 31 0 31 0 Provides a mechanism for an operating system to access the contents of EDECCR that are otherwise invisible to software, so it can save/restore the contents of EDECCR over powerdown on behalf of the external debugger. Debug If DBGOSLSR.OSLK == 0 then DBGOSECCR returns an UNKNOWN value on reads and ignores writes. DBGOSECCR is a 32-bit register. When DBGOSLSR.OSLK == '1' DBGOSLSR.OSLK==1 EDECCR 31 0 31:0 Used for save/restore to EDECCR over powerdown. Reads or writes to this field are indirect accesses to EDECCR. 0x00 When DBGOSLSR.OSLK == '1' MRC{<c>}{<q>} <coproc>, {#}<opc1>, <Rt>, <CRn>, <CRm>{, {#}<opc2>} 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().TDA == '1' then Undefined(); elsif EL2Enabled() && IsFeatureImplemented(FEAT_AA64EL2) && !ELUsingAArch32(EL2) && MDCR_EL2().[TDE,TDA] != '00' then AArch64_AArch32SystemAccessTrap(EL2, 0x05); elsif EL2Enabled() && IsFeatureImplemented(FEAT_AA32EL2) && ELUsingAArch32(EL2) && HDCR().[TDE,TDA] != '00' then AArch32_TakeHypTrapException(0x05); elsif HaveEL(EL3) && IsFeatureImplemented(FEAT_AA64EL3) && !ELUsingAArch32(EL3) && MDCR_EL3().TDA == '1' then if EL3SDDUndef() then Undefined(); else AArch64_AArch32SystemAccessTrap(EL3, 0x05); end; elsif DBGOSLSR().OSLK == '0' then R(t) = ARBITRARY:bits(32); else R(t) = DBGOSECCR(); end; elsif PSTATE.EL == EL2 then if HaveEL(EL3) && EL3SDDUndefPriority() && IsFeatureImplemented(FEAT_AA64EL3) && !ELUsingAArch32(EL3) && MDCR_EL3().TDA == '1' then Undefined(); elsif HaveEL(EL3) && IsFeatureImplemented(FEAT_AA64EL3) && !ELUsingAArch32(EL3) && MDCR_EL3().TDA == '1' then if EL3SDDUndef() then Undefined(); else AArch64_AArch32SystemAccessTrap(EL3, 0x05); end; elsif DBGOSLSR().OSLK == '0' then R(t) = ARBITRARY:bits(32); else R(t) = DBGOSECCR(); end; elsif PSTATE.EL == EL3 then if DBGOSLSR().OSLK == '0' then R(t) = ARBITRARY:bits(32); else R(t) = DBGOSECCR(); end; end; MCR{<c>}{<q>} <coproc>, {#}<opc1>, <Rt>, <CRn>, <CRm>{, {#}<opc2>} 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().TDA == '1' then Undefined(); elsif EL2Enabled() && IsFeatureImplemented(FEAT_AA64EL2) && !ELUsingAArch32(EL2) && MDCR_EL2().[TDE,TDA] != '00' then AArch64_AArch32SystemAccessTrap(EL2, 0x05); elsif EL2Enabled() && IsFeatureImplemented(FEAT_AA32EL2) && ELUsingAArch32(EL2) && HDCR().[TDE,TDA] != '00' then AArch32_TakeHypTrapException(0x05); elsif HaveEL(EL3) && IsFeatureImplemented(FEAT_AA64EL3) && !ELUsingAArch32(EL3) && MDCR_EL3().TDA == '1' then if EL3SDDUndef() then Undefined(); else AArch64_AArch32SystemAccessTrap(EL3, 0x05); end; elsif DBGOSLSR().OSLK == '0' then return; else DBGOSECCR() = R(t); end; elsif PSTATE.EL == EL2 then if HaveEL(EL3) && EL3SDDUndefPriority() && IsFeatureImplemented(FEAT_AA64EL3) && !ELUsingAArch32(EL3) && MDCR_EL3().TDA == '1' then Undefined(); elsif HaveEL(EL3) && IsFeatureImplemented(FEAT_AA64EL3) && !ELUsingAArch32(EL3) && MDCR_EL3().TDA == '1' then if EL3SDDUndef() then Undefined(); else AArch64_AArch32SystemAccessTrap(EL3, 0x05); end; elsif DBGOSLSR().OSLK == '0' then return; else DBGOSECCR() = R(t); end; elsif PSTATE.EL == EL3 then if DBGOSLSR().OSLK == '0' then return; else DBGOSECCR() = R(t); end; end; 2026-03-26 20:27:25 2026-03_rel