System Control Masking Register (EL2)
Mask register to prevent updates of fields in SCTLR_EL2 on writes.
This register is present only when FEAT_SRMASK is implemented and FEAT_AA64 is implemented. Otherwise, direct accesses to SCTLRMASK_EL2 are UNDEFINED.
If EL2 is not implemented, this register is RES0 from EL3.
This register has no effect if EL2 is not enabled in the current Security state.
SCTLRMASK_EL2 is a 64-bit register.
| 63 | 62 | 61 | 60 | 59 | 58 | 57 | 56 | 55 | 54 | 53 | 52 | 51 | 50 | 49 | 48 | 47 | 46 | 45 | 44 | 43 | 42 | 41 | 40 | 39 | 38 | 37 | 36 | 35 | 34 | 33 | 32 |
| 31 | 30 | 29 | 28 | 27 | 26 | 25 | 24 | 23 | 22 | 21 | 20 | 19 | 18 | 17 | 16 | 15 | 14 | 13 | 12 | 11 | 10 | 9 | 8 | 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 |
| TIDCP | SPINTMASK | NMI | EnTP2 | TCSO | TCSO0 | EPAN | EnALS | EnAS0 | EnASR | RES0 | TWEDEL | TWEDEn | DSSBS | ATA | ATA0 | RES0 | TCF | RES0 | TCF0 | ITFSB | BT | BT0 | EnFPM | MSCEn | CMOW | ||||||
| EnIA | EnIB | LSMAOE | nTLSMD | EnDA | UCI | EE | E0E | SPAN | EIS | IESB | TSCXT | WXN | nTWE | RES0 | nTWI | UCT | DZE | EnDB | I | EOS | EnRCTX | RES0 | SED | ITD | nAA | CP15BEN | SA0 | SA | C | A | M |
Mask bit for TIDCP.
| TIDCP | Meaning |
|---|---|
| 0b0 |
SCTLR_EL2.TIDCP is writable. |
| 0b1 |
SCTLR_EL2.TIDCP is not writable. |
The reset behavior of this field is:
Reserved, RES0.
Mask bit for SPINTMASK.
| SPINTMASK | Meaning |
|---|---|
| 0b0 |
SCTLR_EL2.SPINTMASK is writable. |
| 0b1 |
SCTLR_EL2.SPINTMASK is not writable. |
The reset behavior of this field is:
Reserved, RES0.
Mask bit for NMI.
| NMI | Meaning |
|---|---|
| 0b0 |
SCTLR_EL2.NMI is writable. |
| 0b1 |
SCTLR_EL2.NMI is not writable. |
The reset behavior of this field is:
Reserved, RES0.
Mask bit for EnTP2.
| EnTP2 | Meaning |
|---|---|
| 0b0 |
SCTLR_EL2.EnTP2 is writable. |
| 0b1 |
SCTLR_EL2.EnTP2 is not writable. |
The reset behavior of this field is:
Reserved, RES0.
Mask bit for TCSO.
| TCSO | Meaning |
|---|---|
| 0b0 |
SCTLR_EL2.TCSO is writable. |
| 0b1 |
SCTLR_EL2.TCSO is not writable. |
The reset behavior of this field is:
Reserved, RES0.
Mask bit for TCSO0.
| TCSO0 | Meaning |
|---|---|
| 0b0 |
SCTLR_EL2.TCSO0 is writable. |
| 0b1 |
SCTLR_EL2.TCSO0 is not writable. |
The reset behavior of this field is:
Reserved, RES0.
Mask bit for EPAN.
| EPAN | Meaning |
|---|---|
| 0b0 |
SCTLR_EL2.EPAN is writable. |
| 0b1 |
SCTLR_EL2.EPAN is not writable. |
The reset behavior of this field is:
Reserved, RES0.
Mask bit for EnALS.
| EnALS | Meaning |
|---|---|
| 0b0 |
SCTLR_EL2.EnALS is writable. |
| 0b1 |
SCTLR_EL2.EnALS is not writable. |
The reset behavior of this field is:
Reserved, RES0.
Mask bit for EnAS0.
| EnAS0 | Meaning |
|---|---|
| 0b0 |
SCTLR_EL2.EnAS0 is writable. |
| 0b1 |
SCTLR_EL2.EnAS0 is not writable. |
The reset behavior of this field is:
Reserved, RES0.
Mask bit for EnASR.
| EnASR | Meaning |
|---|---|
| 0b0 |
SCTLR_EL2.EnASR is writable. |
| 0b1 |
SCTLR_EL2.EnASR is not writable. |
The reset behavior of this field is:
Reserved, RES0.
Reserved, RES0.
Mask bit for TWEDEL.
| TWEDEL | Meaning |
|---|---|
| 0b0 |
SCTLR_EL2.TWEDEL is writable. |
| 0b1 |
SCTLR_EL2.TWEDEL is not writable. |
The reset behavior of this field is:
Reserved, RES0.
Mask bit for TWEDEn.
| TWEDEn | Meaning |
|---|---|
| 0b0 |
SCTLR_EL2.TWEDEn is writable. |
| 0b1 |
SCTLR_EL2.TWEDEn is not writable. |
The reset behavior of this field is:
Reserved, RES0.
Mask bit for DSSBS.
| DSSBS | Meaning |
|---|---|
| 0b0 |
SCTLR_EL2.DSSBS is writable. |
| 0b1 |
SCTLR_EL2.DSSBS is not writable. |
The reset behavior of this field is:
Reserved, RES0.
Mask bit for ATA.
| ATA | Meaning |
|---|---|
| 0b0 |
SCTLR_EL2.ATA is writable. |
| 0b1 |
SCTLR_EL2.ATA is not writable. |
The reset behavior of this field is:
Reserved, RES0.
Mask bit for ATA0.
| ATA0 | Meaning |
|---|---|
| 0b0 |
SCTLR_EL2.ATA0 is writable. |
| 0b1 |
SCTLR_EL2.ATA0 is not writable. |
The reset behavior of this field is:
Reserved, RES0.
Reserved, RES0.
Mask bit for TCF.
| TCF | Meaning |
|---|---|
| 0b0 |
SCTLR_EL2.TCF is writable. |
| 0b1 |
SCTLR_EL2.TCF is not writable. |
The reset behavior of this field is:
Reserved, RES0.
Reserved, RES0.
Mask bit for TCF0.
| TCF0 | Meaning |
|---|---|
| 0b0 |
SCTLR_EL2.TCF0 is writable. |
| 0b1 |
SCTLR_EL2.TCF0 is not writable. |
The reset behavior of this field is:
Reserved, RES0.
Mask bit for ITFSB.
| ITFSB | Meaning |
|---|---|
| 0b0 |
SCTLR_EL2.ITFSB is writable. |
| 0b1 |
SCTLR_EL2.ITFSB is not writable. |
The reset behavior of this field is:
Reserved, RES0.
Mask bit for BT.
| BT | Meaning |
|---|---|
| 0b0 |
SCTLR_EL2.BT is writable. |
| 0b1 |
SCTLR_EL2.BT is not writable. |
The reset behavior of this field is:
Reserved, RES0.
Mask bit for BT0.
| BT0 | Meaning |
|---|---|
| 0b0 |
SCTLR_EL2.BT0 is writable. |
| 0b1 |
SCTLR_EL2.BT0 is not writable. |
The reset behavior of this field is:
Reserved, RES0.
Mask bit for EnFPM.
| EnFPM | Meaning |
|---|---|
| 0b0 |
SCTLR_EL2.EnFPM is writable. |
| 0b1 |
SCTLR_EL2.EnFPM is not writable. |
The reset behavior of this field is:
Reserved, RES0.
Mask bit for MSCEn.
| MSCEn | Meaning |
|---|---|
| 0b0 |
SCTLR_EL2.MSCEn is writable. |
| 0b1 |
SCTLR_EL2.MSCEn is not writable. |
The reset behavior of this field is:
Reserved, RES0.
Mask bit for CMOW.
| CMOW | Meaning |
|---|---|
| 0b0 |
SCTLR_EL2.CMOW is writable. |
| 0b1 |
SCTLR_EL2.CMOW is not writable. |
The reset behavior of this field is:
Reserved, RES0.
Mask bit for EnIA.
| EnIA | Meaning |
|---|---|
| 0b0 |
SCTLR_EL2.EnIA is writable. |
| 0b1 |
SCTLR_EL2.EnIA is not writable. |
The reset behavior of this field is:
Reserved, RES0.
Mask bit for EnIB.
| EnIB | Meaning |
|---|---|
| 0b0 |
SCTLR_EL2.EnIB is writable. |
| 0b1 |
SCTLR_EL2.EnIB is not writable. |
The reset behavior of this field is:
Reserved, RES0.
Mask bit for LSMAOE.
| LSMAOE | Meaning |
|---|---|
| 0b0 |
SCTLR_EL2.LSMAOE is writable. |
| 0b1 |
SCTLR_EL2.LSMAOE is not writable. |
The reset behavior of this field is:
Reserved, RES0.
Mask bit for nTLSMD.
| nTLSMD | Meaning |
|---|---|
| 0b0 |
SCTLR_EL2.nTLSMD is writable. |
| 0b1 |
SCTLR_EL2.nTLSMD is not writable. |
The reset behavior of this field is:
Reserved, RES0.
Mask bit for EnDA.
| EnDA | Meaning |
|---|---|
| 0b0 |
SCTLR_EL2.EnDA is writable. |
| 0b1 |
SCTLR_EL2.EnDA is not writable. |
The reset behavior of this field is:
Reserved, RES0.
Mask bit for UCI.
| UCI | Meaning |
|---|---|
| 0b0 |
SCTLR_EL2.UCI is writable. |
| 0b1 |
SCTLR_EL2.UCI is not writable. |
The reset behavior of this field is:
Mask bit for EE.
| EE | Meaning |
|---|---|
| 0b0 |
SCTLR_EL2.EE is writable. |
| 0b1 |
SCTLR_EL2.EE is not writable. |
The reset behavior of this field is:
Reserved, RES0.
Mask bit for E0E.
| E0E | Meaning |
|---|---|
| 0b0 |
SCTLR_EL2.E0E is writable. |
| 0b1 |
SCTLR_EL2.E0E is not writable. |
The reset behavior of this field is:
Reserved, RES0.
Mask bit for SPAN.
| SPAN | Meaning |
|---|---|
| 0b0 |
SCTLR_EL2.SPAN is writable. |
| 0b1 |
SCTLR_EL2.SPAN is not writable. |
The reset behavior of this field is:
Mask bit for EIS.
| EIS | Meaning |
|---|---|
| 0b0 |
SCTLR_EL2.EIS is writable. |
| 0b1 |
SCTLR_EL2.EIS is not writable. |
The reset behavior of this field is:
Reserved, RES0.
Mask bit for IESB.
| IESB | Meaning |
|---|---|
| 0b0 |
SCTLR_EL2.IESB is writable. |
| 0b1 |
SCTLR_EL2.IESB is not writable. |
The reset behavior of this field is:
Reserved, RES0.
Mask bit for TSCXT.
| TSCXT | Meaning |
|---|---|
| 0b0 |
SCTLR_EL2.TSCXT is writable. |
| 0b1 |
SCTLR_EL2.TSCXT is not writable. |
The reset behavior of this field is:
Reserved, RES0.
Mask bit for WXN.
| WXN | Meaning |
|---|---|
| 0b0 |
SCTLR_EL2.WXN is writable. |
| 0b1 |
SCTLR_EL2.WXN is not writable. |
The reset behavior of this field is:
Mask bit for nTWE.
| nTWE | Meaning |
|---|---|
| 0b0 |
SCTLR_EL2.nTWE is writable. |
| 0b1 |
SCTLR_EL2.nTWE is not writable. |
The reset behavior of this field is:
Reserved, RES0.
Mask bit for nTWI.
| nTWI | Meaning |
|---|---|
| 0b0 |
SCTLR_EL2.nTWI is writable. |
| 0b1 |
SCTLR_EL2.nTWI is not writable. |
The reset behavior of this field is:
Mask bit for UCT.
| UCT | Meaning |
|---|---|
| 0b0 |
SCTLR_EL2.UCT is writable. |
| 0b1 |
SCTLR_EL2.UCT is not writable. |
The reset behavior of this field is:
Mask bit for DZE.
| DZE | Meaning |
|---|---|
| 0b0 |
SCTLR_EL2.DZE is writable. |
| 0b1 |
SCTLR_EL2.DZE is not writable. |
The reset behavior of this field is:
Mask bit for EnDB.
| EnDB | Meaning |
|---|---|
| 0b0 |
SCTLR_EL2.EnDB is writable. |
| 0b1 |
SCTLR_EL2.EnDB is not writable. |
The reset behavior of this field is:
Reserved, RES0.
Mask bit for I.
| I | Meaning |
|---|---|
| 0b0 |
SCTLR_EL2.I is writable. |
| 0b1 |
SCTLR_EL2.I is not writable. |
The reset behavior of this field is:
Mask bit for EOS.
| EOS | Meaning |
|---|---|
| 0b0 |
SCTLR_EL2.EOS is writable. |
| 0b1 |
SCTLR_EL2.EOS is not writable. |
The reset behavior of this field is:
Reserved, RES0.
Mask bit for EnRCTX.
| EnRCTX | Meaning |
|---|---|
| 0b0 |
SCTLR_EL2.EnRCTX is writable. |
| 0b1 |
SCTLR_EL2.EnRCTX is not writable. |
The reset behavior of this field is:
Reserved, RES0.
Reserved, RES0.
Mask bit for SED.
| SED | Meaning |
|---|---|
| 0b0 |
SCTLR_EL2.SED is writable. |
| 0b1 |
SCTLR_EL2.SED is not writable. |
The reset behavior of this field is:
Reserved, RES0.
Mask bit for ITD.
| ITD | Meaning |
|---|---|
| 0b0 |
SCTLR_EL2.ITD is writable. |
| 0b1 |
SCTLR_EL2.ITD is not writable. |
The reset behavior of this field is:
Reserved, RES0.
Mask bit for nAA.
| nAA | Meaning |
|---|---|
| 0b0 |
SCTLR_EL2.nAA is writable. |
| 0b1 |
SCTLR_EL2.nAA is not writable. |
The reset behavior of this field is:
Mask bit for CP15BEN.
| CP15BEN | Meaning |
|---|---|
| 0b0 |
SCTLR_EL2.CP15BEN is writable. |
| 0b1 |
SCTLR_EL2.CP15BEN is not writable. |
The reset behavior of this field is:
Reserved, RES0.
Mask bit for SA0.
| SA0 | Meaning |
|---|---|
| 0b0 |
SCTLR_EL2.SA0 is writable. |
| 0b1 |
SCTLR_EL2.SA0 is not writable. |
The reset behavior of this field is:
Mask bit for SA.
| SA | Meaning |
|---|---|
| 0b0 |
SCTLR_EL2.SA is writable. |
| 0b1 |
SCTLR_EL2.SA is not writable. |
The reset behavior of this field is:
Mask bit for C.
| C | Meaning |
|---|---|
| 0b0 |
SCTLR_EL2.C is writable. |
| 0b1 |
SCTLR_EL2.C is not writable. |
The reset behavior of this field is:
Mask bit for A.
| A | Meaning |
|---|---|
| 0b0 |
SCTLR_EL2.A is writable. |
| 0b1 |
SCTLR_EL2.A is not writable. |
The reset behavior of this field is:
Mask bit for M.
| M | Meaning |
|---|---|
| 0b0 |
SCTLR_EL2.M is writable. |
| 0b1 |
SCTLR_EL2.M is not writable. |
The reset behavior of this field is:
When the Effective value of HCR_EL2.E2H is 1, without explicit synchronization, accesses from EL2 using the accessor name SCTLRMASK_EL2 or SCTLRMASK_EL1 are not guaranteed to be ordered with respect to accesses using the other accessor name.
Accesses to this register use the following encodings in the System register encoding space:
MRS <Xt>, SCTLRMASK_EL2
(op0 = 0b11, op1 = 0b100, CRn = 0b0001, CRm = 0b0100, op2 = 0b000)
if !(IsFeatureImplemented(FEAT_SRMASK) && IsFeatureImplemented(FEAT_AA64)) then Undefined(); elsif HaveEL(EL3) && PSTATE.EL == EL2 && EL3SDDUndefPriority() && SCR_EL3().SRMASKEn == '0' then Undefined(); elsif PSTATE.EL == EL0 then Undefined(); elsif PSTATE.EL == EL1 then if EffectiveHCR_EL2_NVx() IN {'xx1'} then AArch64_SystemAccessTrap(EL2, 0x18); else Undefined(); end; elsif PSTATE.EL == EL2 then if HaveEL(EL3) && SCR_EL3().SRMASKEn == '0' then if EL3SDDUndef() then Undefined(); else AArch64_SystemAccessTrap(EL3, 0x18); end; else X{64}(t) = SCTLRMASK_EL2(); end; elsif PSTATE.EL == EL3 then X{64}(t) = SCTLRMASK_EL2(); end;
MSR SCTLRMASK_EL2, <Xt>
(op0 = 0b11, op1 = 0b100, CRn = 0b0001, CRm = 0b0100, op2 = 0b000)
if !(IsFeatureImplemented(FEAT_SRMASK) && IsFeatureImplemented(FEAT_AA64)) then Undefined(); elsif HaveEL(EL3) && PSTATE.EL == EL2 && EL3SDDUndefPriority() && SCR_EL3().SRMASKEn == '0' then Undefined(); elsif PSTATE.EL == EL0 then Undefined(); elsif PSTATE.EL == EL1 then if EffectiveHCR_EL2_NVx() IN {'xx1'} then AArch64_SystemAccessTrap(EL2, 0x18); else Undefined(); end; elsif PSTATE.EL == EL2 then if HaveEL(EL3) && SCR_EL3().SRMASKEn == '0' then if EL3SDDUndef() then Undefined(); else AArch64_SystemAccessTrap(EL3, 0x18); end; elsif !IsZero(SCTLRMASK_EL2()) then Undefined(); else SCTLRMASK_EL2() = X{64}(t); end; elsif PSTATE.EL == EL3 then SCTLRMASK_EL2() = X{64}(t); end;
MRS <Xt>, SCTLRMASK_EL1
(op0 = 0b11, op1 = 0b000, CRn = 0b0001, CRm = 0b0100, op2 = 0b000)
if !(IsFeatureImplemented(FEAT_SRMASK) && IsFeatureImplemented(FEAT_AA64)) then Undefined(); elsif HaveEL(EL3) && !(EffectivelyAtEL0InHost() || EffectivelyAtEL0NotInHost() || PSTATE.EL == EL3) && EL3SDDUndefPriority() && SCR_EL3().SRMASKEn == '0' then Undefined(); elsif PSTATE.EL == EL0 then Undefined(); elsif PSTATE.EL == EL1 then if EL2Enabled() && IsFeatureImplemented(FEAT_FGT2) && ((HaveEL(EL3) && SCR_EL3().FGTEn2 == '0') || HFGRTR2_EL2().nSCTLRMASK_EL1 == '0') then AArch64_SystemAccessTrap(EL2, 0x18); elsif EL2Enabled() && (!IsHCRXEL2Enabled() || HCRX_EL2().SRMASKEn == '0') then AArch64_SystemAccessTrap(EL2, 0x18); elsif HaveEL(EL3) && SCR_EL3().SRMASKEn == '0' then if EL3SDDUndef() then Undefined(); else AArch64_SystemAccessTrap(EL3, 0x18); end; elsif EffectiveHCR_EL2_NVx() IN {'111'} then X{64}(t) = NVMem(0x318); else X{64}(t) = SCTLRMASK_EL1(); end; elsif PSTATE.EL == EL2 then if HaveEL(EL3) && SCR_EL3().SRMASKEn == '0' then if EL3SDDUndef() then Undefined(); else AArch64_SystemAccessTrap(EL3, 0x18); end; elsif ELIsInHost(EL2) then X{64}(t) = SCTLRMASK_EL2(); else X{64}(t) = SCTLRMASK_EL1(); end; elsif PSTATE.EL == EL3 then X{64}(t) = SCTLRMASK_EL1(); end;
MSR SCTLRMASK_EL1, <Xt>
(op0 = 0b11, op1 = 0b000, CRn = 0b0001, CRm = 0b0100, op2 = 0b000)
if !(IsFeatureImplemented(FEAT_SRMASK) && IsFeatureImplemented(FEAT_AA64)) then Undefined(); elsif HaveEL(EL3) && !(EffectivelyAtEL0InHost() || EffectivelyAtEL0NotInHost() || PSTATE.EL == EL3) && EL3SDDUndefPriority() && SCR_EL3().SRMASKEn == '0' then Undefined(); elsif PSTATE.EL == EL0 then Undefined(); elsif PSTATE.EL == EL1 then if EL2Enabled() && IsFeatureImplemented(FEAT_FGT2) && ((HaveEL(EL3) && SCR_EL3().FGTEn2 == '0') || HFGWTR2_EL2().nSCTLRMASK_EL1 == '0') then AArch64_SystemAccessTrap(EL2, 0x18); elsif EL2Enabled() && (!IsHCRXEL2Enabled() || HCRX_EL2().SRMASKEn == '0') then AArch64_SystemAccessTrap(EL2, 0x18); elsif HaveEL(EL3) && SCR_EL3().SRMASKEn == '0' then if EL3SDDUndef() then Undefined(); else AArch64_SystemAccessTrap(EL3, 0x18); end; elsif EffectiveHCR_EL2_NVx() IN {'111'} then NVMem(0x318) = X{64}(t); elsif !IsZero(SCTLRMASK_EL1()) then Undefined(); else SCTLRMASK_EL1() = X{64}(t); end; elsif PSTATE.EL == EL2 then if HaveEL(EL3) && SCR_EL3().SRMASKEn == '0' then if EL3SDDUndef() then Undefined(); else AArch64_SystemAccessTrap(EL3, 0x18); end; elsif ELIsInHost(EL2) then if !IsZero(SCTLRMASK_EL2()) then Undefined(); else SCTLRMASK_EL2() = X{64}(t); end; else SCTLRMASK_EL1() = X{64}(t); end; elsif PSTATE.EL == EL3 then SCTLRMASK_EL1() = X{64}(t); end;
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