EL0 Read/Write Software Thread ID Register
Provides a location where software executing at EL0 can store thread identifying information, for OS management purposes.
The PE makes no use of this register.
AArch64 System register TPIDR_EL0 bits [31:0] are architecturally mapped to AArch32 System register TPIDRURW[31:0].
This register is present only when FEAT_AA64 is implemented. Otherwise, direct accesses to TPIDR_EL0 are UNDEFINED.
TPIDR_EL0 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 |
| ThreadID | |||||||||||||||||||||||||||||||
| ThreadID | |||||||||||||||||||||||||||||||
Thread ID. Thread identifying information stored by software running at this Exception level.
The reset behavior of this field is:
Accesses to this register use the following encodings in the System register encoding space:
MRS <Xt>, TPIDR_EL0
(op0 = 0b11, op1 = 0b011, CRn = 0b1101, CRm = 0b0000, op2 = 0b010)
if !IsFeatureImplemented(FEAT_AA64) then Undefined(); elsif PSTATE.EL == EL0 then if EL2Enabled() && EffectivelyAtEL0NotInHost() && IsFeatureImplemented(FEAT_FGT) && (!HaveEL(EL3) || SCR_EL3().FGTEn == '1') && HFGRTR_EL2().TPIDR_EL0 == '1' then AArch64_SystemAccessTrap(EL2, 0x18); else X{64}(t) = TPIDR_EL0(); end; elsif PSTATE.EL == EL1 then if EL2Enabled() && IsFeatureImplemented(FEAT_FGT) && (!HaveEL(EL3) || SCR_EL3().FGTEn == '1') && HFGRTR_EL2().TPIDR_EL0 == '1' then AArch64_SystemAccessTrap(EL2, 0x18); else X{64}(t) = TPIDR_EL0(); end; elsif PSTATE.EL == EL2 then X{64}(t) = TPIDR_EL0(); elsif PSTATE.EL == EL3 then X{64}(t) = TPIDR_EL0(); end;
MSR TPIDR_EL0, <Xt>
(op0 = 0b11, op1 = 0b011, CRn = 0b1101, CRm = 0b0000, op2 = 0b010)
if !IsFeatureImplemented(FEAT_AA64) then Undefined(); elsif PSTATE.EL == EL0 then if EL2Enabled() && EffectivelyAtEL0NotInHost() && IsFeatureImplemented(FEAT_FGT) && (!HaveEL(EL3) || SCR_EL3().FGTEn == '1') && HFGWTR_EL2().TPIDR_EL0 == '1' then AArch64_SystemAccessTrap(EL2, 0x18); else TPIDR_EL0() = X{64}(t); end; elsif PSTATE.EL == EL1 then if EL2Enabled() && IsFeatureImplemented(FEAT_FGT) && (!HaveEL(EL3) || SCR_EL3().FGTEn == '1') && HFGWTR_EL2().TPIDR_EL0 == '1' then AArch64_SystemAccessTrap(EL2, 0x18); else TPIDR_EL0() = X{64}(t); end; elsif PSTATE.EL == EL2 then TPIDR_EL0() = X{64}(t); elsif PSTATE.EL == EL3 then TPIDR_EL0() = X{64}(t); end;
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