The ID_MMFR5_EL1 characteristics are:
Provides information about the implemented memory model and memory management support in AArch32 state.
For general information about the interpretation of the ID registers see 'Principles of the ID scheme for fields in ID registers' in the Arm® Architecture Reference Manual, Armv8, for Armv8-A architecture profile, section D10.4.1.
AArch64 System register ID_MMFR5_EL1 bits [31:0] are architecturally mapped to AArch32 System register ID_MMFR5[31:0] .
In an implementation that supports only AArch64 state, this register is UNKNOWN.
ID_MMFR5_EL1 is a 64-bit register.
The ID_MMFR5_EL1 bit assignments are:
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 |
RES0 | |||||||||||||||||||||||||||||||
RES0 | ETS | ||||||||||||||||||||||||||||||
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 |
Reserved, RES0.
Support for Enhanced Translation Synchronization. Defined values are:
ETS | Meaning |
---|---|
0b0000 |
Enhanced Translation Synchronization is not supported. |
0b0001 |
Enhanced Translation Synchronization is supported. |
All other values are reserved.
ARMv8.0-ETS implements the functionality identified by the value 0b0001.
From Armv8.0, the permitted values are 0b0000 and 0b0001.
Reserved, RES0.
Accesses to this register use the following encodings:
op0 | op1 | CRn | CRm | op2 |
---|---|---|---|---|
0b11 | 0b000 | 0b0000 | 0b0011 | 0b110 |
if PSTATE.EL == EL0 then UNDEFINED; elsif PSTATE.EL == EL1 then if IsFeatureImplemented("Morello") && !CapIsSystemAccessEnabled() && !Halted() then if TargetELForCapabilityExceptions() == EL1 then AArch64.SystemAccessTrap(EL1, 0x18); elsif TargetELForCapabilityExceptions() == EL2 then AArch64.SystemAccessTrap(EL2, 0x18); else AArch64.SystemAccessTrap(EL3, 0x18); elsif EL2Enabled() && !ELUsingAArch32(EL2) && (!IsZero(ID_MMFR5_EL1) || boolean IMPLEMENTATION_DEFINED "ID_MMFR5_EL1 trapped by HCR_EL2.TID3") && HCR_EL2.TID3 == '1' then AArch64.SystemAccessTrap(EL2, 0x18); else return ID_MMFR5_EL1; elsif PSTATE.EL == EL2 then if IsFeatureImplemented("Morello") && !CapIsSystemAccessEnabled() && !Halted() then if TargetELForCapabilityExceptions() == EL2 then AArch64.SystemAccessTrap(EL2, 0x18); else AArch64.SystemAccessTrap(EL3, 0x18); else return ID_MMFR5_EL1; elsif PSTATE.EL == EL3 then if IsFeatureImplemented("Morello") && !CapIsSystemAccessEnabled() && !Halted() then AArch64.SystemAccessTrap(EL3, 0x18); else return ID_MMFR5_EL1;
12/01/2022 09:56; 05a4944b4b04e7ab50def8c126b479d22136f35b
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