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# APDBKeyHi_EL1, Pointer Authentication Key B for Data (bits[127:64])

The APDBKeyHi_EL1 characteristics are:

## Purpose

Holds bits[127:64] of key B used for authentication of data pointer values.

Note

The term APDBKey_EL1 is used to describe the concatenation of APDBKeyHi_EL1: APDBKeyLo_EL1.

## Configuration

This register is present only when ARMv8.3-PAuth is implemented. Otherwise, direct accesses to APDBKeyHi_EL1 are UNDEFINED.

RW fields in this register reset to architecturally UNKNOWN values.

## Attributes

APDBKeyHi_EL1 is a 64-bit register.

## Field descriptions

The APDBKeyHi_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[127:64] of the 128 bit pointer authentication key value
64 bit value, bits[127:64] 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

#### Bits [63:0]

64 bit value, bits[127:64] of the 128 bit pointer authentication key value.

This field resets to an architecturally UNKNOWN value.

## Accessing the APDBKeyHi_EL1

Accesses to this register use the following encodings:

#### MRS <Xt>, APDBKeyHi_EL1

op0 | op1 | CRn | CRm | op2
--- | --- | --- | --- | ---
0b11 | 0b000 | 0b0010 | 0b0010 | 0b011

if PSTATE.EL == EL0 then UNDEFINED; elsif PSTATE.EL == EL1 then if EL2Enabled() && !ELUsingAArch32(EL2) && HCR_EL2.APK == '0' then AArch64.SystemAccessTrap(EL2, 0x18); elsif HaveEL(EL3) && !ELUsingAArch32(EL3) && SCR_EL3.APK == '0' then AArch64.SystemAccessTrap(EL3, 0x18); else return APDBKeyHi_EL1; elsif PSTATE.EL == EL2 then if HaveEL(EL3) && !ELUsingAArch32(EL3) && SCR_EL3.APK == '0' then AArch64.SystemAccessTrap(EL3, 0x18); else return APDBKeyHi_EL1; elsif PSTATE.EL == EL3 then return APDBKeyHi_EL1;

#### MSR APDBKeyHi_EL1, <Xt>

op0 | op1 | CRn | CRm | op2
--- | --- | --- | --- | ---
0b11 | 0b000 | 0b0010 | 0b0010 | 0b011

if PSTATE.EL == EL0 then UNDEFINED; elsif PSTATE.EL == EL1 then if EL2Enabled() && !ELUsingAArch32(EL2) && HCR_EL2.APK == '0' then AArch64.SystemAccessTrap(EL2, 0x18); elsif HaveEL(EL3) && !ELUsingAArch32(EL3) && SCR_EL3.APK == '0' then AArch64.SystemAccessTrap(EL3, 0x18); else APDBKeyHi_EL1 = X[t]; elsif PSTATE.EL == EL2 then if HaveEL(EL3) && !ELUsingAArch32(EL3) && SCR_EL3.APK == '0' then AArch64.SystemAccessTrap(EL3, 0x18); else APDBKeyHi_EL1 = X[t]; elsif PSTATE.EL == EL3 then APDBKeyHi_EL1 = X[t];

AArch32 Registers | AArch64 Registers | AArch32 Instructions | AArch64 Instructions | Index by Encoding | External Registers | External Registers by Offset | Registers by Functional Group | Proprietary Notice

15/04/2019 16:47; 8c23526ba8a13a72aada4137daf3e3977b49036e

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