System Control
ARM DDI 0500D
Copyright © 2013-2014 ARM. All rights reserved.
4-55
ID021414
Non-Confidential
To access the SCTLR_EL1:
MRS <Xt>, SCTLR_EL1 ; Read SCTLR_EL1 into Xt
MSR SCTLR_EL1, <Xt> ; Write Xt to SCTLR_EL1
4.3.31
Auxiliary Control Register, EL1
The processor does not implement the ACTLR_EL1 register. This register is always
RES
0.
4.3.32
Auxiliary Control Register, EL2
The ACTLR_EL2 characteristics are:
Purpose
Controls write access to
IMPLEMENTATION
DEFINED
registers in
Non-secure EL1 modes, such as CPUACTLR, CPUECTLR, L2CTLR,
L2ECTLR and L2ACTLR.
Usage constraints
This register is accessible as follows:
Configurations
The ACTLR_EL2 is architecturally mapped to the AArch32 HACTLR
register. See
Hyp Auxiliary Control Register
on page 4-205
.
Attributes
ACTLR_EL2 is a 32-bit register.
Figure 4-29
shows the ACTLR_EL2 bit assignments.
Figure 4-29 ACTLR_EL2 bit assignments
[0]
M
MMU enable. The possible values are:
0
EL1 and EL0 stage 1 MMU disabled. This is the reset value.
1
EL1 and EL0 stage 1 MMU enabled.
Table 4-67 SCTLR_EL1 bit assignments (continued)
Bits
Name
Function
EL0
EL1
(NS)
EL1
(S)
EL2
EL3
(SCR.NS = 1)
EL3
(SCR.NS = 0)
-
-
-
RW
RW
RW
31
0
RES
0
L2ACTLR_EL1 access control
1
2
3
4
5
6
7
L2ECTLR_EL1 access control
L2CTLR_EL1 access control
CPUECTLR_EL1 access control
CPUACTLR_EL1 access control
RES
0