System Control
ARM DDI 0500D
Copyright © 2013-2014 ARM. All rights reserved.
4-217
ID021414
Non-Confidential
Usage constraints
This register is accessible as follows:
Configurations
HCR2 is architecturally mapped to AArch64 register HCR_EL2[63:32].
This register is accessible only at EL2 or EL3.
Attributes
HCR2 is a 32-bit register.
Figure 4-108
shows the HCR2 bit assignments.
Figure 4-108 HCR2 bit assignments
Table 4-203
shows the HCR2 bit assignments.
To access the HCR2:
MRC p15,4,<Rt>,c1,c1,4 ; Read HCR2 into Rt
MCR p15,4,<Rt>,c1,c1,4 ; Write Rt to HCR2
4.5.38
Hyp Debug Control Register
The HDCR characteristics are:
Purpose
Controls the trapping to Hyp mode of Non-secure accesses, at EL1 or
lower, to functions provided by the debug and trace architectures and the
Performance Monitor.
EL0
(NS)
EL0
(S)
EL1
(NS)
EL1
(S)
EL2
EL3
(SCR.NS = 1)
EL3
(SCR.NS = 0)
-
-
-
-
RW
RW
-
RES
0
31
0
CD
ID
1
2
Table 4-203 HCR2 bit assignments
Bits
Name
Function
[31:2]
-
Reserved,
RES
0.
[1]
ID
Stage 2 Instruction cache disable. When HCR.VM is 1, this forces all stage 2 translations for instruction accesses
to Normal memory to be Non-cacheable for the EL1/EL0 translation regime. The possible values are:
0
No effect on the stage 2 of the EL1/EL0 translation regime for instruction accesses.
1
Forces all stage 2 translations for instruction accesses to Normal memory to be Non-cacheable
for the EL0/EL1 translation regime.
[0]
CD
Stage 2 Data cache disable. When HCR.VM is 1, this forces all stage 2 translations for data accesses and
translation table walks to Normal memory to be Non-cacheable for the EL1/EL0 translation regime. The
possible values are:
0
No effect on the stage 2 of the EL1/EL0 translation regime for data accesses and translation table
walks.
1
Forces all stage 2 translations for data accesses and translation table walks to Normal memory
to be Non-cacheable for the EL0/EL1 translation regime.