APGAKeyLo

This register is present only when FEAT_PAuth is implemented. Otherwise, direct accesses to APGAKeyLo_EL1 are UNDEFINED.

Attributes

Field descriptions

Bits [63:0]

Accessing APGAKeyLo_EL1

Accesses to this register use the following encodings in the System register encoding space:

MRS <Xt>, APGAKeyLo_EL1

op0	op1	CRn	CRm	op2
0b11	0b000	0b0010	0b0011	0b000

if PSTATE.EL == EL0 then UNDEFINED; elsif PSTATE.EL == EL1 then if HaveEL(EL3) && EL3SDDUndefPriority() && SCR_EL3.APK == '0' then UNDEFINED; elsif EL2Enabled() && HCR_EL2.APK == '0' then AArch64.SystemAccessTrap(EL2, 0x18); elsif EL2Enabled() && IsFeatureImplemented(FEAT_FGT) && (!HaveEL(EL3) || SCR_EL3.FGTEn == '1') && HFGRTR_EL2.APGAKey == '1' then AArch64.SystemAccessTrap(EL2, 0x18); elsif HaveEL(EL3) && SCR_EL3.APK == '0' then if EL3SDDUndef() then UNDEFINED; else AArch64.SystemAccessTrap(EL3, 0x18); else X[t, 64] = APGAKeyLo_EL1; elsif PSTATE.EL == EL2 then if HaveEL(EL3) && EL3SDDUndefPriority() && SCR_EL3.APK == '0' then UNDEFINED; elsif HaveEL(EL3) && SCR_EL3.APK == '0' then if EL3SDDUndef() then UNDEFINED; else AArch64.SystemAccessTrap(EL3, 0x18); else X[t, 64] = APGAKeyLo_EL1; elsif PSTATE.EL == EL3 then X[t, 64] = APGAKeyLo_EL1;

MSR APGAKeyLo_EL1, <Xt>

op0	op1	CRn	CRm	op2
0b11	0b000	0b0010	0b0011	0b000

if PSTATE.EL == EL0 then UNDEFINED; elsif PSTATE.EL == EL1 then if HaveEL(EL3) && EL3SDDUndefPriority() && SCR_EL3.APK == '0' then UNDEFINED; elsif EL2Enabled() && HCR_EL2.APK == '0' then AArch64.SystemAccessTrap(EL2, 0x18); elsif EL2Enabled() && IsFeatureImplemented(FEAT_FGT) && (!HaveEL(EL3) || SCR_EL3.FGTEn == '1') && HFGWTR_EL2.APGAKey == '1' then AArch64.SystemAccessTrap(EL2, 0x18); elsif HaveEL(EL3) && SCR_EL3.APK == '0' then if EL3SDDUndef() then UNDEFINED; else AArch64.SystemAccessTrap(EL3, 0x18); else APGAKeyLo_EL1 = X[t, 64]; elsif PSTATE.EL == EL2 then if HaveEL(EL3) && EL3SDDUndefPriority() && SCR_EL3.APK == '0' then UNDEFINED; elsif HaveEL(EL3) && SCR_EL3.APK == '0' then if EL3SDDUndef() then UNDEFINED; else AArch64.SystemAccessTrap(EL3, 0x18); else APGAKeyLo_EL1 = X[t, 64]; elsif PSTATE.EL == EL3 then APGAKeyLo_EL1 = X[t, 64];

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

APGAKeyLo_EL1, Pointer Authentication Key A for Code (bits[63:0])