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:
| 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 |
| 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>}
| coproc | opc1 | CRn | CRm | opc2 |
|---|---|---|---|---|
| 0b1111 | 0b000 | 0b0110 | 0b0000 | 0b000 |
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>}
| coproc | opc1 | CRn | CRm | opc2 |
|---|---|---|---|---|
| 0b1111 | 0b000 | 0b0110 | 0b0000 | 0b000 |
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];