TPIDR_EL1, EL1 Software Thread ID Register

The TPIDR_EL1 characteristics are:

Purpose

Provides a location where software executing at EL1 can store thread identifying information, for OS management purposes.

The PE makes no use of this register.

Configuration

AArch64 System register TPIDR_EL1 bits [31:0] are architecturally mapped to AArch32 System register TPIDRPRW[31:0] .

RW fields in this register reset to architecturally UNKNOWN values.

Attributes

TPIDR_EL1 is a 64-bit register.

Field descriptions

The TPIDR_EL1 bit assignments are:

6362616059585756555453525150494847464544434241403938373635343332
Thread ID
Thread ID
313029282726252423222120191817161514131211109876543210

Bits [63:0]

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

This field resets to an architecturally UNKNOWN value.

Accessing the TPIDR_EL1

Accesses to this register use the following encodings:

MRS <Xt>, TPIDR_EL1

op0op1CRnCRmop2
0b110b0000b11010b00000b100

if PSTATE.EL == EL0 then UNDEFINED; elsif PSTATE.EL == EL1 then return TPIDR_EL1; elsif PSTATE.EL == EL2 then return TPIDR_EL1; elsif PSTATE.EL == EL3 then return TPIDR_EL1;

MSR TPIDR_EL1, <Xt>

op0op1CRnCRmop2
0b110b0000b11010b00000b100

if PSTATE.EL == EL0 then UNDEFINED; elsif PSTATE.EL == EL1 then TPIDR_EL1 = X[t]; elsif PSTATE.EL == EL2 then TPIDR_EL1 = X[t]; elsif PSTATE.EL == EL3 then TPIDR_EL1 = X[t];




27/03/2019 21:59; e5e4db499bf9867a4b93324c4dbac985d3da9376

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