Multiple tag transfer ID Register
Indicates the block size that is accessed by the LDGM and STGM System instructions.
This register is present only when FEAT_MTE2 is implemented. Otherwise, direct accesses to GMID_EL1 are UNDEFINED.
GMID_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 | BS | ||||||||||||||||||||||||||||||
Reserved, RES0.
Log2 of the block size in words. The minimum supported size is 16B (value == 2) and the maximum is 256B (value == 6).
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>, GMID_EL1
(op0 = 0b11, op1 = 0b001, CRn = 0b0000, CRm = 0b0000, op2 = 0b100)
if !IsFeatureImplemented(FEAT_MTE2) then UnimplementedIDRegister(); elsif PSTATE.EL == EL0 then if IsFeatureImplemented(FEAT_IDST) then if EL2Enabled() && HCR_EL2.TGE == '1' then AArch64.SystemAccessTrap(EL2, 0x18); else AArch64.SystemAccessTrap(EL1, 0x18); else UNDEFINED; elsif PSTATE.EL == EL1 then if HaveEL(EL3) && EL3SDDUndefPriority() && IsFeatureImplemented(FEAT_IDTE3) && SCR_EL3.TID5 == '1' then UNDEFINED; elsif EL2Enabled() && HCR_EL2.TID5 == '1' then AArch64.SystemAccessTrap(EL2, 0x18); elsif HaveEL(EL3) && IsFeatureImplemented(FEAT_IDTE3) && SCR_EL3.TID5 == '1' then if EL3SDDUndef() then UNDEFINED; else AArch64.SystemAccessTrap(EL3, 0x18); else X[t, 64] = GMID_EL1; elsif PSTATE.EL == EL2 then if HaveEL(EL3) && EL3SDDUndefPriority() && IsFeatureImplemented(FEAT_IDTE3) && SCR_EL3.TID5 == '1' then UNDEFINED; elsif HaveEL(EL3) && IsFeatureImplemented(FEAT_IDTE3) && SCR_EL3.TID5 == '1' then if EL3SDDUndef() then UNDEFINED; else AArch64.SystemAccessTrap(EL3, 0x18); else X[t, 64] = GMID_EL1; elsif PSTATE.EL == EL3 then X[t, 64] = GMID_EL1;
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