version: "1.0.0" name: xiangshan-mpt-dut description: Generate or update a compact Chisel/Scala DUT that isolates XiangShan MPT checking logic from the full core. Use when working on XiangShan MPT, MptChecker.scala, L2TLB MPT wiring, backend/decode mfence support, or the custom smmpt/mmpt CSR path, especially when asked to regenerate a simple DUT around MPT upstream/downstream logic for simulation or verification.

XiangShan MPT DUT

Workflow

Use this skill to rebuild a small DUT around XiangShan's MPT checker without dragging in the whole core.

1. Inspect the local XiangShan source before editing. Prefer rg and targeted sed reads.
2. Load references/mpt-dut-generation.md before implementing the DUT.
3. Keep the DUT focused on MptChecker and its real upstream/downstream contract:

• upstream request/response: MptReqBundle and MptRespBundle
• CSR input: TlbCsrBundle.mmpt
• flush input: SfenceBundle, including mfence when HasMptCheck
• memory side: L2TlbMemReqBundle request plus XLEN response
• PMP side: PMPReqBundle and PMPRespBundle

1. Preserve the XiangShan parameter gate: the DUT should be meaningful only with HasMptCheck = true.
2. Do not model the full backend, ROB, LSQ, PTW cluster, or complete L2TLB unless the user explicitly asks. Replace them with small drivers, arbiters, memories, or stubs that preserve handshake semantics.

Output Shape

Prefer one of these forms, matching the repository style:

• A new Chisel module such as SimpleMptDUT, MptCheckerDUT, or a project-specific name requested by the user.
• A minimal test/harness module that instantiates MptChecker, drives CSR/mfence/PMP/memory, and exposes decoupled request/response IO.
• A generator target only if the repository already has a clear pattern for standalone generators.

Keep source changes narrow. Avoid unrelated CSR, decode, or L2TLB refactors.

Validation

After generating the DUT:

• Run the narrowest available Scala/Chisel compile or generator command for the touched module.
• If no compile target exists, run a syntax-oriented check available in the repo and state the limitation.
• Recheck all Option.when(HasMptCheck) fields so the DUT does not dereference optional mfence or MPT fields when disabled.