APAS
Associate PA space
when FEAT_RME_GPC3 is implemented and FEAT_AA64 is implemented
Associate a location with a specified PA space, for locations that are protected by a memory-side PAS filter.
Root
APAS is a 64-bit System instruction.
NS
63
63
63
Together with the NSE field, selects the target physical address space.
NSENSMeaning
0b00b0When Secure state is implemented, Secure. Otherwise reserved.
0b00b1Non-secure.
0b10b0Root.
0b10b1Realm.
NSE
62
62
62
Together with the NS field, selects the target physical address space.
For a description of the values derived by evaluating NS and NSE together, see APAS.NS.
61
56
61:56
Reserved, RES0.
PA
55
6
55:6
Bits [55:6] of the Physical Address.
Bits of Xt corresponding to physical address bits above the implemented physical address size indicated in ID_AA64MMFR0_EL1.PARange are RES0. For example, if 44 bits of PA space are implemented, then Xt[55:44] are RES0.
5
3
5:3
Reserved, RES0.
TargetAttributes
2
0
2:0
The Target Attributes field is encoded as follows:
0b000
Default behavior applies.
0b001..0b111
IMPLEMENTATION DEFINED.
This instruction is not subject to any translation, permission checks, or granule protection checks.
This system instruction is an alias of the SYS instruction.
APAS <Xt>
if !(IsFeatureImplemented(FEAT_RME_GPC3) && IsFeatureImplemented(FEAT_AA64)) then
Undefined();
elsif PSTATE.EL == EL0 then
Undefined();
elsif PSTATE.EL == EL1 then
Undefined();
elsif PSTATE.EL == EL2 then
Undefined();
elsif PSTATE.EL == EL3 then
AArch64_APAS(X{64}(t));
end;
2026-03-26 20:27:25
2026-03_rel