Indicates the number of LORegions and LORegion descriptors supported by the PE.
This register is present only when FEAT_LOR is implemented. Otherwise, direct accesses to LORID_EL1 are UNDEFINED.
If no LORegion descriptors are implemented, then the registers LORC_EL1, LORN_EL1, LOREA_EL1, and LORSA_EL1 are RES0.
LORID_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 | LD | RES0 | LR | ||||||||||||||||||||||||||||
Reserved, RES0.
Number of LORegion descriptors supported by the PE. This is an 8-bit binary number.
This field has an IMPLEMENTATION DEFINED value.
Access to this field is RO.
Reserved, RES0.
Number of LORegions supported by the PE. This is an 8-bit binary number.
If LORID_EL1 indicates that no LORegions are implemented, then LoadLOAcquire and StoreLORelease will behave as LoadAcquire and StoreRelease.
This field has an IMPLEMENTATION DEFINED value.
Access to this field is RO.
Accesses to this register use the following encodings in the System register encoding space:
MRS <Xt>, LORID_EL1
| op0 | op1 | CRn | CRm | op2 |
|---|---|---|---|---|
| 0b11 | 0b000 | 0b1010 | 0b0100 | 0b111 |
if PSTATE.EL == EL0 then UNDEFINED; elsif PSTATE.EL == EL1 then if HaveEL(EL3) && EL3SDDUndefPriority() && SCR_EL3.TLOR == '1' then UNDEFINED; elsif EL2Enabled() && HCR_EL2.TLOR == '1' then AArch64.SystemAccessTrap(EL2, 0x18); elsif EL2Enabled() && IsFeatureImplemented(FEAT_FGT) && (!HaveEL(EL3) || SCR_EL3.FGTEn == '1') && HFGRTR_EL2.LORID_EL1 == '1' then AArch64.SystemAccessTrap(EL2, 0x18); elsif HaveEL(EL3) && SCR_EL3.TLOR == '1' then if EL3SDDUndef() then UNDEFINED; else AArch64.SystemAccessTrap(EL3, 0x18); else X[t, 64] = LORID_EL1; elsif PSTATE.EL == EL2 then if HaveEL(EL3) && EL3SDDUndefPriority() && SCR_EL3.TLOR == '1' then UNDEFINED; elsif HaveEL(EL3) && SCR_EL3.TLOR == '1' then if EL3SDDUndef() then UNDEFINED; else AArch64.SystemAccessTrap(EL3, 0x18); else X[t, 64] = LORID_EL1; elsif PSTATE.EL == EL3 then X[t, 64] = LORID_EL1;