# VM Architecture Mirror Policy

The Prometeu runtime repository is the normative authority for PBX binary
layout, Core ISA, loader behavior, verification, and PVM execution semantics.
The files in this directory are convenience mirrors for Studio-side compiler
and integration work; they are not an independent architectural authority.

Canonical runtime sources:

- `../runtime/docs/vm-arch/ARCHITECTURE.md`
- `../runtime/docs/vm-arch/ISA_CORE.md`
- `../runtime/docs/vm-arch/INTRINSICS.csv`

When these mirrors are retained, an integration change that updates a canonical
runtime source MUST update the corresponding Studio mirror in the same logical
change. Verify synchronization from the Studio repository root with:

```bash
diff -u docs/vm-arch/ARCHITECTURE.md ../runtime/docs/vm-arch/ARCHITECTURE.md
diff -u docs/vm-arch/ISA_CORE.md ../runtime/docs/vm-arch/ISA_CORE.md
diff -u docs/vm-arch/INTRINSICS.csv ../runtime/docs/vm-arch/INTRINSICS.csv
```

All three commands MUST exit successfully with no output before a change claims
that the mirrors are synchronized. If the runtime repository is not available
in the same checkout, synchronization evidence must be produced against the
canonical runtime revision before merging.

Compiler-owned transformation contracts remain under `docs/specs/compiler`.
Those specifications define `IRBackend -> IRVM -> PBX` emission, but they MUST
conform to the runtime-owned PBX and ISA contracts and MUST NOT redefine runtime
execution semantics.