Branch to sealed capability pair checks the capabilities have the correct properties to be used as a sealed pair, unseals the source Capability registers, branches to an address in the first Capability register and writes the second Capability register to C29.
| 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 |
| 1 | 1 | 0 | 0 | 0 | 0 | 1 | 0 | 1 | 1 | 0 | Cm | 1 | 0 | 0 | 0 | 0 | 1 | Cn | 0 | 0 | 0 | 0 | 0 | ||||||||
| opc<1> | opc<0> | ||||||||||||||||||||||||||||||
integer n = UInt(Cn); integer m = UInt(Cm); BranchType branch_type = BranchType_INDIR;
| <Cn> |
Is the capability name of the first source register, encoded in the "Cn" field. |
| <Cm> |
Is the capability name of the second source register, encoded in the "Cm" field. |
CheckCapabilitiesEnabled(); Capability sealed_target = C[n]; Capability sealed_data = C[m]; if !IsInRestricted() && !CapCheckPermissions(sealed_target, CAP_PERM_EXECUTIVE) then sealed_target = CapWithTagClear(sealed_target); Capability target; if CapIsTagSet(sealed_target) && CapIsTagSet(sealed_data) && CapIsSealed(sealed_target) && CapIsSealed(sealed_data) && UInt(CapGetObjectType(sealed_target)) > CAP_MAX_FIXED_SEAL_TYPE && CapGetObjectType(sealed_target) == CapGetObjectType(sealed_data) && CapCheckPermissions(sealed_target, CAP_PERM_BRANCH_SEALED_PAIR) && CapCheckPermissions(sealed_data, CAP_PERM_BRANCH_SEALED_PAIR) && CapCheckPermissions(sealed_target, CAP_PERM_EXECUTE) && !CapCheckPermissions(sealed_data, CAP_PERM_EXECUTE) then target = CapUnseal(sealed_target); C[29] = CapUnseal(sealed_data); else target = CapWithTagClear(sealed_target); C[29] = sealed_data; BranchXToCapability(target, branch_type);
Internal version only: isa v32.13, AdvSIMD v29.04, pseudocode morello-2022-01_rc2, capabilities morello-2022-01_rc2 ; Build timestamp: 2022-01-11T11:23
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