Random Allocation Tag Seed Register.
Random Allocation Tag Seed Register.
This register is present only when FEAT_MTE2 is implemented. Otherwise, direct accesses to RGSR_EL1 are UNDEFINED.
When GCR_EL1.RRND is 1, updates to RGSR_EL1 are implementation-specific.
RGSR_EL1 is a Special-purpose register.
RGSR_EL1 is a 64-bit register.
| 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 |
| RES0 | |||||||||||||||||||||||||||||||
| RES0 | SEED | RES0 | TAG | ||||||||||||||||||||||||||||
Reserved, RES0.
Seed register used for generating values returned by RandomTag() or, if FEAT_MTE_EIRG is implemented, ChooseTag()
The reset behavior of this field is:
Reserved, RES0.
Tag generated by the most recent IRG instruction or, if FEAT_MTE_EIRG is implemented, EIRG state
The reset behavior of this field is:
| 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 |
| RES0 | SEED | ||||||||||||||||||||||||||||||
| SEED | RES0 | TAG | |||||||||||||||||||||||||||||
Reserved, RES0.
IMPLEMENTATION DEFINED.
Software is recommended to avoid writing SEED[15:0] with a value of zero, unless this has been generated by the PE in response to an earlier value with SEED being nonzero.
The reset behavior of this field is:
Reserved, RES0.
IMPLEMENTATION DEFINED.
The reset behavior of this field is:
Accesses to this register use the following encodings in the System register encoding space:
MRS <Xt>, RGSR_EL1
(op0 = 0b11, op1 = 0b000, CRn = 0b0001, CRm = 0b0000, op2 = 0b101)
if !IsFeatureImplemented(FEAT_MTE2) then Undefined(); elsif HaveEL(EL3) && !(EffectivelyAtEL0InHost() || EffectivelyAtEL0NotInHost() || PSTATE.EL == EL3) && EL3SDDUndefPriority() && !(IsFeatureImplemented(FEAT_MTE2) && SCR_EL3().ATA == '1') then Undefined(); elsif PSTATE.EL == EL0 then Undefined(); elsif PSTATE.EL == EL1 then if EL2Enabled() && !ELIsInHost(EL0) && !(IsFeatureImplemented(FEAT_MTE2) && HCR_EL2().ATA == '1') then AArch64_SystemAccessTrap(EL2, 0x18); elsif HaveEL(EL3) && !(IsFeatureImplemented(FEAT_MTE2) && SCR_EL3().ATA == '1') then if EL3SDDUndef() then Undefined(); else AArch64_SystemAccessTrap(EL3, 0x18); end; else X{64}(t) = RGSR_EL1(); end; elsif PSTATE.EL == EL2 then if HaveEL(EL3) && !(IsFeatureImplemented(FEAT_MTE2) && SCR_EL3().ATA == '1') then if EL3SDDUndef() then Undefined(); else AArch64_SystemAccessTrap(EL3, 0x18); end; else X{64}(t) = RGSR_EL1(); end; elsif PSTATE.EL == EL3 then X{64}(t) = RGSR_EL1(); end;
MSR RGSR_EL1, <Xt>
(op0 = 0b11, op1 = 0b000, CRn = 0b0001, CRm = 0b0000, op2 = 0b101)
if !IsFeatureImplemented(FEAT_MTE2) then Undefined(); elsif HaveEL(EL3) && !(EffectivelyAtEL0InHost() || EffectivelyAtEL0NotInHost() || PSTATE.EL == EL3) && EL3SDDUndefPriority() && !(IsFeatureImplemented(FEAT_MTE2) && SCR_EL3().ATA == '1') then Undefined(); elsif PSTATE.EL == EL0 then Undefined(); elsif PSTATE.EL == EL1 then if EL2Enabled() && !ELIsInHost(EL0) && !(IsFeatureImplemented(FEAT_MTE2) && HCR_EL2().ATA == '1') then AArch64_SystemAccessTrap(EL2, 0x18); elsif HaveEL(EL3) && !(IsFeatureImplemented(FEAT_MTE2) && SCR_EL3().ATA == '1') then if EL3SDDUndef() then Undefined(); else AArch64_SystemAccessTrap(EL3, 0x18); end; else RGSR_EL1() = X{64}(t); end; elsif PSTATE.EL == EL2 then if HaveEL(EL3) && !(IsFeatureImplemented(FEAT_MTE2) && SCR_EL3().ATA == '1') then if EL3SDDUndef() then Undefined(); else AArch64_SystemAccessTrap(EL3, 0x18); end; else RGSR_EL1() = X{64}(t); end; elsif PSTATE.EL == EL3 then RGSR_EL1() = X{64}(t); end;
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