TPIDRRO

Provides a location where software executing at EL1 or higher can store thread identifying information that is visible to software executing at EL0, for OS management purposes.

Configuration

AArch64 System register TPIDRRO_EL0 bits [31:0] are architecturally mapped to AArch32 System register TPIDRURO[31:0].

This register is present only when FEAT_AA64 is implemented. Otherwise, direct accesses to TPIDRRO_EL0 are UNDEFINED.

Attributes

Field descriptions

ThreadID, bits [63:0]

Accessing TPIDRRO_EL0

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

MRS <Xt>, TPIDRRO_EL0

op0	op1	CRn	CRm	op2
0b11	0b011	0b1101	0b0000	0b011

if !IsFeatureImplemented(FEAT_AA64) then UNDEFINED; elsif PSTATE.EL == EL0 then if EL2Enabled() && !ELIsInHost(EL0) && IsFeatureImplemented(FEAT_FGT) && (!HaveEL(EL3) || SCR_EL3.FGTEn == '1') && HFGRTR_EL2.TPIDRRO_EL0 == '1' then AArch64.SystemAccessTrap(EL2, 0x18); else X[t, 64] = TPIDRRO_EL0; elsif PSTATE.EL == EL1 then if EL2Enabled() && IsFeatureImplemented(FEAT_FGT) && (!HaveEL(EL3) || SCR_EL3.FGTEn == '1') && HFGRTR_EL2.TPIDRRO_EL0 == '1' then AArch64.SystemAccessTrap(EL2, 0x18); else X[t, 64] = TPIDRRO_EL0; elsif PSTATE.EL == EL2 then X[t, 64] = TPIDRRO_EL0; elsif PSTATE.EL == EL3 then X[t, 64] = TPIDRRO_EL0;

MSR TPIDRRO_EL0, <Xt>

op0	op1	CRn	CRm	op2
0b11	0b011	0b1101	0b0000	0b011

if !IsFeatureImplemented(FEAT_AA64) then UNDEFINED; elsif PSTATE.EL == EL0 then UNDEFINED; elsif PSTATE.EL == EL1 then if EL2Enabled() && IsFeatureImplemented(FEAT_FGT) && (!HaveEL(EL3) || SCR_EL3.FGTEn == '1') && HFGWTR_EL2.TPIDRRO_EL0 == '1' then AArch64.SystemAccessTrap(EL2, 0x18); else TPIDRRO_EL0 = X[t, 64]; elsif PSTATE.EL == EL2 then TPIDRRO_EL0 = X[t, 64]; elsif PSTATE.EL == EL3 then TPIDRRO_EL0 = 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
ThreadID
ThreadID

TPIDRRO_EL0, EL0 Read-Only Software Thread ID Register