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TPIDR2_EL0: EL0 Read/Write Software Thread ID Register 2

Purpose

Provides a location where SME-aware software executing at EL0 can store thread identifying information, for context management purposes.

The PE makes no use of this register.

Configuration

This register is present only when FEAT_SME is implemented. Otherwise, direct accesses to TPIDR2_EL0 are UNDEFINED.

Attributes

TPIDR2_EL0 is a 64-bit register.

Field descriptions

6362616059585756555453525150494847464544434241403938373635343332
313029282726252423222120191817161514131211109876543210
Thread ID
Thread ID

Bits [63:0]

Thread identifying information stored by software running at this Exception level.

The reset behavior of this field is:

Accessing TPIDR2_EL0

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

MRS <Xt>, TPIDR2_EL0

op0op1CRnCRmop2
0b110b0110b11010b00000b101

if PSTATE.EL == EL0 then if HaveEL(EL3) && EL3SDDUndefPriority() && SCR_EL3.EnTP2 == '0' then UNDEFINED; elsif !ELIsInHost(EL0) && SCTLR_EL1.EnTP2 == '0' then if EL2Enabled() && HCR_EL2.TGE == '1' then AArch64.SystemAccessTrap(EL2, 0x18); else AArch64.SystemAccessTrap(EL1, 0x18); elsif ELIsInHost(EL0) && SCTLR_EL2.EnTP2 == '0' then AArch64.SystemAccessTrap(EL2, 0x18); elsif EL2Enabled() && !ELIsInHost(EL0) && IsFeatureImplemented(FEAT_FGT) && (!HaveEL(EL3) || SCR_EL3.FGTEn == '1') && HFGRTR_EL2.nTPIDR2_EL0 == '0' then AArch64.SystemAccessTrap(EL2, 0x18); elsif HaveEL(EL3) && SCR_EL3.EnTP2 == '0' then if EL3SDDUndef() then UNDEFINED; else AArch64.SystemAccessTrap(EL3, 0x18); else X[t, 64] = TPIDR2_EL0; elsif PSTATE.EL == EL1 then if HaveEL(EL3) && EL3SDDUndefPriority() && SCR_EL3.EnTP2 == '0' then UNDEFINED; elsif EL2Enabled() && IsFeatureImplemented(FEAT_FGT) && (!HaveEL(EL3) || SCR_EL3.FGTEn == '1') && HFGRTR_EL2.nTPIDR2_EL0 == '0' then AArch64.SystemAccessTrap(EL2, 0x18); elsif HaveEL(EL3) && SCR_EL3.EnTP2 == '0' then if EL3SDDUndef() then UNDEFINED; else AArch64.SystemAccessTrap(EL3, 0x18); else X[t, 64] = TPIDR2_EL0; elsif PSTATE.EL == EL2 then if HaveEL(EL3) && EL3SDDUndefPriority() && SCR_EL3.EnTP2 == '0' then UNDEFINED; elsif HaveEL(EL3) && SCR_EL3.EnTP2 == '0' then if EL3SDDUndef() then UNDEFINED; else AArch64.SystemAccessTrap(EL3, 0x18); else X[t, 64] = TPIDR2_EL0; elsif PSTATE.EL == EL3 then X[t, 64] = TPIDR2_EL0;

MSR TPIDR2_EL0, <Xt>

op0op1CRnCRmop2
0b110b0110b11010b00000b101

if PSTATE.EL == EL0 then if HaveEL(EL3) && EL3SDDUndefPriority() && SCR_EL3.EnTP2 == '0' then UNDEFINED; elsif !ELIsInHost(EL0) && SCTLR_EL1.EnTP2 == '0' then if EL2Enabled() && HCR_EL2.TGE == '1' then AArch64.SystemAccessTrap(EL2, 0x18); else AArch64.SystemAccessTrap(EL1, 0x18); elsif ELIsInHost(EL0) && SCTLR_EL2.EnTP2 == '0' then AArch64.SystemAccessTrap(EL2, 0x18); elsif EL2Enabled() && !ELIsInHost(EL0) && IsFeatureImplemented(FEAT_FGT) && (!HaveEL(EL3) || SCR_EL3.FGTEn == '1') && HFGWTR_EL2.nTPIDR2_EL0 == '0' then AArch64.SystemAccessTrap(EL2, 0x18); elsif HaveEL(EL3) && SCR_EL3.EnTP2 == '0' then if EL3SDDUndef() then UNDEFINED; else AArch64.SystemAccessTrap(EL3, 0x18); else TPIDR2_EL0 = X[t, 64]; elsif PSTATE.EL == EL1 then if HaveEL(EL3) && EL3SDDUndefPriority() && SCR_EL3.EnTP2 == '0' then UNDEFINED; elsif EL2Enabled() && IsFeatureImplemented(FEAT_FGT) && (!HaveEL(EL3) || SCR_EL3.FGTEn == '1') && HFGWTR_EL2.nTPIDR2_EL0 == '0' then AArch64.SystemAccessTrap(EL2, 0x18); elsif HaveEL(EL3) && SCR_EL3.EnTP2 == '0' then if EL3SDDUndef() then UNDEFINED; else AArch64.SystemAccessTrap(EL3, 0x18); else TPIDR2_EL0 = X[t, 64]; elsif PSTATE.EL == EL2 then if HaveEL(EL3) && EL3SDDUndefPriority() && SCR_EL3.EnTP2 == '0' then UNDEFINED; elsif HaveEL(EL3) && SCR_EL3.EnTP2 == '0' then if EL3SDDUndef() then UNDEFINED; else AArch64.SystemAccessTrap(EL3, 0x18); else TPIDR2_EL0 = X[t, 64]; elsif PSTATE.EL == EL3 then TPIDR2_EL0 = X[t, 64];