DFAR, Data Fault Address Register

The DFAR characteristics are:

Purpose

Holds the virtual address of the faulting address that caused a synchronous Data Abort exception.

Configuration

AArch32 System register DFAR bits [31:0] are architecturally mapped to AArch64 System register FAR_EL1[31:0] .

AArch32 System register DFAR bits [31:0] (S) are architecturally mapped to AArch32 System register HDFAR[31:0] when EL2 is implemented, EL3 is implemented and the highest implemented Exception level is using AArch32 state.

This register is present only when AArch32 is supported at any Exception level. Otherwise, direct accesses to DFAR are UNDEFINED.

Attributes

DFAR is a 32-bit register.

Field descriptions

The DFAR bit assignments are:

313029282726252423222120191817161514131211109876543210
VA of faulting address of synchronous Data Abort exception

Bits [31:0]

VA of faulting address of synchronous Data Abort exception.

This field resets to an architecturally UNKNOWN value.

Accessing the DFAR

Accesses to this register use the following encodings:

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

coprocopc1CRnCRmopc2
0b11110b0000b01100b00000b000

if PSTATE.EL == EL0 then UNDEFINED; elsif PSTATE.EL == EL1 then if EL2Enabled() && !ELUsingAArch32(EL2) && HSTR_EL2.T6 == '1' then AArch64.AArch32SystemAccessTrap(EL2, 0x03); elsif EL2Enabled() && ELUsingAArch32(EL2) && HSTR.T6 == '1' then AArch32.TakeHypTrapException(0x03); elsif EL2Enabled() && !ELUsingAArch32(EL2) && HCR_EL2.TRVM == '1' then AArch64.AArch32SystemAccessTrap(EL2, 0x03); elsif EL2Enabled() && ELUsingAArch32(EL2) && HCR.TRVM == '1' then AArch32.TakeHypTrapException(0x03); elsif HaveEL(EL3) && ELUsingAArch32(EL3) then return DFAR_NS; else return DFAR; elsif PSTATE.EL == EL2 then if HaveEL(EL3) && ELUsingAArch32(EL3) then return DFAR_NS; else return DFAR; elsif PSTATE.EL == EL3 then if SCR.NS == '0' then return DFAR_S; else return DFAR_NS;

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

coprocopc1CRnCRmopc2
0b11110b0000b01100b00000b000

if PSTATE.EL == EL0 then UNDEFINED; elsif PSTATE.EL == EL1 then if EL2Enabled() && !ELUsingAArch32(EL2) && HSTR_EL2.T6 == '1' then AArch64.AArch32SystemAccessTrap(EL2, 0x03); elsif EL2Enabled() && ELUsingAArch32(EL2) && HSTR.T6 == '1' then AArch32.TakeHypTrapException(0x03); elsif EL2Enabled() && !ELUsingAArch32(EL2) && HCR_EL2.TVM == '1' then AArch64.AArch32SystemAccessTrap(EL2, 0x03); elsif EL2Enabled() && ELUsingAArch32(EL2) && HCR.TVM == '1' then AArch32.TakeHypTrapException(0x03); elsif HaveEL(EL3) && ELUsingAArch32(EL3) then DFAR_NS = R[t]; else DFAR = R[t]; elsif PSTATE.EL == EL2 then if HaveEL(EL3) && ELUsingAArch32(EL3) then DFAR_NS = R[t]; else DFAR = R[t]; elsif PSTATE.EL == EL3 then if SCR.NS == '0' then DFAR_S = R[t]; else DFAR_NS = R[t];




01/07/2020 15:57; 80324f0b9997bede489cc15ad1565345720bcd2a

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