.xsil·reproducible·RISC-V

The pre-silicon bridge for RISC-V extensions

Reproducible .xsil packages for simulator, toolchain, and optional FPGA/RTL evaluation.

Operated as an open registry and interim technical steward — not a marketplace. We coordinate publication and technical work; we do not hold funds or process payments. Governance · Contributing

or build a runnable .xsil skeleton in the wizard

Try a runnable extension in one command.

quickstart — xsil

The xsil CLI is published on crates.io. Resolved dependencies are fetched, hash-verified, and cached locally.

Pre-silicon evaluation

Execution pipeline

From source code to reproducible runs on the RISC-V targets your package declares.

Write

Author your RISC-V extension with a manifest.json and a RISC-V toolchain

manifest.json

Package

The CLI bundles your RISC-V extension into a .xsil archive with SHA-256 checksums

.xsil

Publish

xsil publish uploads to the registry — indexed and discoverable instantly

xsil publish

Install

Install from the registry with one command, verified by checksum

xsil install

Evaluate before RTL/FPGA/ASIC

Use Spike, QEMU, FPGA, or other declared targets — hands-on evaluation before heavier RTL/ASIC commitments

xsil run

Why ExtenSilica?

Built for RISC-V

Designed specifically for packaging, distributing, and running RISC-V ISA extensions.

Package registry

Every .xsil package has a canonical name, version history, and a discoverable metadata page — install with xsil install when you are ready to run it locally.

Versioned publishing

Publish new versions with xsil publish. Each version is immutable and permanently addressable by slug@version.

Flexible reproducibility

Publish with bundled, resolved, or host-dependent resolution modes. Optional registry checks help when you mirror tool artifacts on ExtenSilica; host-provided toolchains stay in your README.

Run from the CLI

xsil run, xsil install, and xsil test work with registry slugs, local .xsil files, or unpacked directories.

RV32I| RV64GC| RVV 1.0| Zbkb| Custom ISA

Latest extensions

Browse registry

Ship your extension

Define your manifest.json, register your tool artifacts in ExtenSilica, then run xsil publish. Publish is gated until every declared dependency is verified. Need help coordinating an implementation? Use open requests — funding stays off-platform.

$ cargo install xsil# one-time

$ xsil login && xsil publish ./my-pkg/