The APDAKeyLo_EL1 characteristics are:
Holds bits[63:0] of key A used for authentication of data pointer values.
The term APDAKey_EL1 is used to describe the concatenation of APDAKeyHi_EL1: APDAKeyLo_EL1.
This register is part of the Pointer authentication functional group.
RW fields in this register reset to architecturally UNKNOWN values.
This register is introduced in ARMv8.3.
APDAKeyLo_EL1 is a 64-bit register.
The APDAKeyLo_EL1 bit assignments are:
63 | 62 | 61 | 60 | 59 | 58 | 57 | 56 | 55 | 54 | 53 | 52 | 51 | 50 | 49 | 48 | 47 | 46 | 45 | 44 | 43 | 42 | 41 | 40 | 39 | 38 | 37 | 36 | 35 | 34 | 33 | 32 |
64 bit value, bits[63:0] of the 128 bit pointer authentication key value | |||||||||||||||||||||||||||||||
64 bit value, bits[63:0] of the 128 bit pointer authentication key value | |||||||||||||||||||||||||||||||
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 |
64 bit value, bits[63:0] of the 128 bit pointer authentication key value.
This register can be read using MRS with the following syntax:
MRS <Xt>, <systemreg>
This register can be written using MSR (register) with the following syntax:
MSR <systemreg>, <Xt>
This syntax uses the following encoding in the System instruction encoding space:
<systemreg> | op0 | op1 | CRn | CRm | op2 |
---|---|---|---|---|---|
APDAKeyLo_EL1 | 11 | 000 | 0010 | 0010 | 000 |
The register is accessible as follows:
Control | Accessibility | |||||
---|---|---|---|---|---|---|
E2H | TGE | NS | EL0 | EL1 | EL2 | EL3 |
x | x | 0 | - | RW | n/a | RW |
x | 0 | 1 | - | RW | RW | RW |
x | 1 | 1 | - | n/a | RW | RW |
This table applies to all instructions that can access this register.
For a description of the prioritization of any generated exceptions, see section D1.13.2 (Synchronous exception prioritization) in the ARM® Architecture Reference Manual, ARMv8, for ARMv8-A architecture profile. Subject to the prioritization rules, the following traps and enables are applicable when accessing this register.
When EL2 is implemented and is using AArch64 and SCR_EL3.NS==1 :
If HCR_EL2.APK==0, Non-secure accesses to this register from EL1 are trapped to EL2.
When EL3 is implemented and is using AArch64 :
If SCR_EL3.APK==0, accesses to this register from EL1 and EL2 are trapped to EL3.
28/09/2017 08:24
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