APDAKeyLo_EL1, Pointer Authentication Key A for Data (bits[63:0])

The APDAKeyLo_EL1 characteristics are:

Purpose

Holds bits[63:0] of key A used for authentication of data pointer values.

Note

The term APDAKey_EL1 is used to describe the concatenation of APDAKeyHi_EL1: APDAKeyLo_EL1.

Configuration

This register is present only when FEAT_PAuth is implemented. Otherwise, direct accesses to APDAKeyLo_EL1 are UNDEFINED.

Attributes

APDAKeyLo_EL1 is a 64-bit register.

Field descriptions

The APDAKeyLo_EL1 bit assignments are:

6362616059585756555453525150494847464544434241403938373635343332
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
313029282726252423222120191817161514131211109876543210

Bits [63:0]

64 bit value, bits[63:0] of the 128 bit pointer authentication key value.

On a Warm reset, this field resets to an architecturally UNKNOWN value.

Accessing the APDAKeyLo_EL1

Accesses to this register use the following encodings:

MRS <Xt>, APDAKeyLo_EL1

op0op1CRnCRmop2
0b110b0000b00100b00100b000

if PSTATE.EL == EL0 then UNDEFINED; elsif PSTATE.EL == EL1 then if Halted() && HaveEL(EL3) && EDSCR.SDD == '1' && boolean IMPLEMENTATION_DEFINED "EL3 trap priority when SDD == '1'" && SCR_EL3.APK == '0' then UNDEFINED; elsif EL2Enabled() && HCR_EL2.APK == '0' then AArch64.SystemAccessTrap(EL2, 0x18); elsif EL2Enabled() && (!HaveEL(EL3) || SCR_EL3.FGTEn == '1') && HFGRTR_EL2.APDAKey == '1' then AArch64.SystemAccessTrap(EL2, 0x18); elsif HaveEL(EL3) && SCR_EL3.APK == '0' then if Halted() && EDSCR.SDD == '1' then UNDEFINED; else AArch64.SystemAccessTrap(EL3, 0x18); else return APDAKeyLo_EL1; elsif PSTATE.EL == EL2 then if Halted() && HaveEL(EL3) && EDSCR.SDD == '1' && boolean IMPLEMENTATION_DEFINED "EL3 trap priority when SDD == '1'" && SCR_EL3.APK == '0' then UNDEFINED; elsif HaveEL(EL3) && SCR_EL3.APK == '0' then if Halted() && EDSCR.SDD == '1' then UNDEFINED; else AArch64.SystemAccessTrap(EL3, 0x18); else return APDAKeyLo_EL1; elsif PSTATE.EL == EL3 then return APDAKeyLo_EL1;

MSR APDAKeyLo_EL1, <Xt>

op0op1CRnCRmop2
0b110b0000b00100b00100b000

if PSTATE.EL == EL0 then UNDEFINED; elsif PSTATE.EL == EL1 then if Halted() && HaveEL(EL3) && EDSCR.SDD == '1' && boolean IMPLEMENTATION_DEFINED "EL3 trap priority when SDD == '1'" && SCR_EL3.APK == '0' then UNDEFINED; elsif EL2Enabled() && HCR_EL2.APK == '0' then AArch64.SystemAccessTrap(EL2, 0x18); elsif EL2Enabled() && (!HaveEL(EL3) || SCR_EL3.FGTEn == '1') && HFGWTR_EL2.APDAKey == '1' then AArch64.SystemAccessTrap(EL2, 0x18); elsif HaveEL(EL3) && SCR_EL3.APK == '0' then if Halted() && EDSCR.SDD == '1' then UNDEFINED; else AArch64.SystemAccessTrap(EL3, 0x18); else APDAKeyLo_EL1 = X[t]; elsif PSTATE.EL == EL2 then if Halted() && HaveEL(EL3) && EDSCR.SDD == '1' && boolean IMPLEMENTATION_DEFINED "EL3 trap priority when SDD == '1'" && SCR_EL3.APK == '0' then UNDEFINED; elsif HaveEL(EL3) && SCR_EL3.APK == '0' then if Halted() && EDSCR.SDD == '1' then UNDEFINED; else AArch64.SystemAccessTrap(EL3, 0x18); else APDAKeyLo_EL1 = X[t]; elsif PSTATE.EL == EL3 then APDAKeyLo_EL1 = X[t];




30/09/2020 15:07; ccead0cb9f089f9ceec50268e82aec9e71047211

Copyright © 2010-2020 Arm Limited or its affiliates. All rights reserved. This document is Non-Confidential.