l4v/spec/abstract/
This directory contains the main Isabelle sources of the seL4 abstract
specification. The specification draws in additional interface files from
design and machine.
The specification is written in monadic style. See l4v/lib/wp/NonDetMonad
for the definition of this monad.
The top-level theory file that draws the whole specification together is
Syscall_A, the top-level function in that theory is call_kernel.
This top-level function defines in-kernel behaviour. Later in the proof,
in particular in invariant-abstract, this function is further wrapped
in an automaton that describes system behaviour.
Two useful entry points for browsing the abstract specification are the
theories Structures_A and ARM_Structs_A. They define the state space
of the kernel model, including what capabilities and kernel objects are.
The theories Invocations_A and ArchInvocation_A define datatypes for
the capability invocations/operations the kernel understands.
Most theories are named after the subsystem of the kernel they specify.
The corresponding Isabelle session is ASpec. It is set up to build a
human-readable PDF document. Glossary_Doc contains definitions of common
seL4 terms.
To build, run in directory l4v/spec:
make ASpec
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Note that this specification is actually an extensible family of specifications, with predefined extension points. These points can either be left generic, as for most of the abstract invariant proofs, or they can be instantiated to more precise behaviour, such as in the theory
Deterministic_A, which is used for the information flow proofs. -
The theory
Init_Adoes not define real kernel initialisation. Instead it is a dummy initial state for the kernel to demonstrate non-emptiness of abstract kernel invariants. -
KernelInit_Ais a paused project and not currently included in the rest of the specification.