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AMAIR2_EL2: Extended Auxiliary Memory Attribute Indirection Register (EL2)

Purpose

Provides IMPLEMENTATION DEFINED memory attributes for the memory regions specified by MAIR2_EL2.

Configuration

This register is present only when FEAT_AIE is implemented. Otherwise, direct accesses to AMAIR2_EL2 are UNDEFINED.

If EL2 is not implemented, this register is RES0 from EL3.

Attributes

AMAIR2_EL2 is a 64-bit register.

Field descriptions

6362616059585756555453525150494847464544434241403938373635343332
313029282726252423222120191817161514131211109876543210
IMPLEMENTATION DEFINED
IMPLEMENTATION DEFINED

IMPLEMENTATION DEFINED, bits [63:0]

IMPLEMENTATION DEFINED.

Accessing AMAIR2_EL2

When the Effective value of HCR_EL2.E2H is 1, without explicit synchronization, accesses from EL2 using the register name AMAIR2_EL2 or AMAIR2_EL1 are not guaranteed to be ordered with respect to accesses using the other register name.

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

MRS <Xt>, AMAIR2_EL2

op0op1CRnCRmop2
0b110b1000b10100b00110b001

if PSTATE.EL == EL0 then UNDEFINED; elsif PSTATE.EL == EL1 then if EffectiveHCR_EL2_NVx() IN {'xx1'} then AArch64.SystemAccessTrap(EL2, 0x18); else UNDEFINED; elsif PSTATE.EL == EL2 then if HaveEL(EL3) && EL3SDDUndefPriority() && SCR_EL3.AIEn == '0' then UNDEFINED; elsif HaveEL(EL3) && SCR_EL3.AIEn == '0' then if EL3SDDUndef() then UNDEFINED; else AArch64.SystemAccessTrap(EL3, 0x18); else X[t, 64] = AMAIR2_EL2; elsif PSTATE.EL == EL3 then X[t, 64] = AMAIR2_EL2;

MSR AMAIR2_EL2, <Xt>

op0op1CRnCRmop2
0b110b1000b10100b00110b001

if PSTATE.EL == EL0 then UNDEFINED; elsif PSTATE.EL == EL1 then if EffectiveHCR_EL2_NVx() IN {'xx1'} then AArch64.SystemAccessTrap(EL2, 0x18); else UNDEFINED; elsif PSTATE.EL == EL2 then if HaveEL(EL3) && EL3SDDUndefPriority() && SCR_EL3.AIEn == '0' then UNDEFINED; elsif HaveEL(EL3) && SCR_EL3.AIEn == '0' then if EL3SDDUndef() then UNDEFINED; else AArch64.SystemAccessTrap(EL3, 0x18); else AMAIR2_EL2 = X[t, 64]; elsif PSTATE.EL == EL3 then AMAIR2_EL2 = X[t, 64];

MRS <Xt>, AMAIR2_EL1

op0op1CRnCRmop2
0b110b0000b10100b00110b001

if PSTATE.EL == EL0 then UNDEFINED; elsif PSTATE.EL == EL1 then if HaveEL(EL3) && EL3SDDUndefPriority() && SCR_EL3.AIEn == '0' then UNDEFINED; elsif EL2Enabled() && HCR_EL2.TRVM == '1' then AArch64.SystemAccessTrap(EL2, 0x18); elsif EL2Enabled() && IsFeatureImplemented(FEAT_FGT) && (!HaveEL(EL3) || SCR_EL3.FGTEn == '1') && HFGRTR_EL2.nAMAIR2_EL1 == '0' then AArch64.SystemAccessTrap(EL2, 0x18); elsif HaveEL(EL3) && SCR_EL3.AIEn == '0' then if EL3SDDUndef() then UNDEFINED; else AArch64.SystemAccessTrap(EL3, 0x18); elsif EffectiveHCR_EL2_NVx() == '111' then X[t, 64] = NVMem[0x288]; else X[t, 64] = AMAIR2_EL1; elsif PSTATE.EL == EL2 then if HaveEL(EL3) && EL3SDDUndefPriority() && SCR_EL3.AIEn == '0' then UNDEFINED; elsif HaveEL(EL3) && SCR_EL3.AIEn == '0' then if EL3SDDUndef() then UNDEFINED; else AArch64.SystemAccessTrap(EL3, 0x18); elsif ELIsInHost(EL2) then X[t, 64] = AMAIR2_EL2; else X[t, 64] = AMAIR2_EL1; elsif PSTATE.EL == EL3 then X[t, 64] = AMAIR2_EL1;

MSR AMAIR2_EL1, <Xt>

op0op1CRnCRmop2
0b110b0000b10100b00110b001

if PSTATE.EL == EL0 then UNDEFINED; elsif PSTATE.EL == EL1 then if HaveEL(EL3) && EL3SDDUndefPriority() && SCR_EL3.AIEn == '0' then UNDEFINED; elsif EL2Enabled() && HCR_EL2.TVM == '1' then AArch64.SystemAccessTrap(EL2, 0x18); elsif EL2Enabled() && IsFeatureImplemented(FEAT_FGT) && (!HaveEL(EL3) || SCR_EL3.FGTEn == '1') && HFGWTR_EL2.nAMAIR2_EL1 == '0' then AArch64.SystemAccessTrap(EL2, 0x18); elsif HaveEL(EL3) && SCR_EL3.AIEn == '0' then if EL3SDDUndef() then UNDEFINED; else AArch64.SystemAccessTrap(EL3, 0x18); elsif EffectiveHCR_EL2_NVx() == '111' then NVMem[0x288] = X[t, 64]; else AMAIR2_EL1 = X[t, 64]; elsif PSTATE.EL == EL2 then if HaveEL(EL3) && EL3SDDUndefPriority() && SCR_EL3.AIEn == '0' then UNDEFINED; elsif HaveEL(EL3) && SCR_EL3.AIEn == '0' then if EL3SDDUndef() then UNDEFINED; else AArch64.SystemAccessTrap(EL3, 0x18); elsif ELIsInHost(EL2) then AMAIR2_EL2 = X[t, 64]; else AMAIR2_EL1 = X[t, 64]; elsif PSTATE.EL == EL3 then AMAIR2_EL1 = X[t, 64];