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APIBKeyHi_EL1, Pointer Authentication Key B for Instruction (bits[127:64])

The APIBKeyHi_EL1 characteristics are:

Purpose

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

Note

The term APIBKey_EL1 is used to describe the concatenation of APIBKeyHi_EL1: APIBKeyLo_EL1.

Configuration

This register is present only when ARMv8.3-PAuth is implemented. Otherwise, direct accesses to APIBKeyHi_EL1 are UNDEFINED.

RW fields in this register reset to architecturally UNKNOWN values.

Attributes

APIBKeyHi_EL1 is a 64-bit register.

Field descriptions

The APIBKeyHi_EL1 bit assignments are:

6362616059585756555453525150494847464544434241403938373635343332
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
313029282726252423222120191817161514131211109876543210

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 APIBKeyHi_EL1

Accesses to this register use the following encodings:

MRS <Xt>, APIBKeyHi_EL1

CRnop0op1op2CRm
0b00100b110b0000b0110b0001
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 APIBKeyHi_EL1;
elsif PSTATE.EL == EL2 then
    if HaveEL(EL3) && !ELUsingAArch32(EL3) && SCR_EL3.APK == '0' then
        AArch64.SystemAccessTrap(EL3, 0x18);
    else
        return APIBKeyHi_EL1;
elsif PSTATE.EL == EL3 then
    return APIBKeyHi_EL1;
              

MSR APIBKeyHi_EL1, <Xt>

CRnop0op1op2CRm
0b00100b110b0000b0110b0001
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
        APIBKeyHi_EL1 = X[t];
elsif PSTATE.EL == EL2 then
    if HaveEL(EL3) && !ELUsingAArch32(EL3) && SCR_EL3.APK == '0' then
        AArch64.SystemAccessTrap(EL3, 0x18);
    else
        APIBKeyHi_EL1 = X[t];
elsif PSTATE.EL == EL3 then
    APIBKeyHi_EL1 = X[t];
              


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