cloudparts

Renode

Antmicro’s simulator for embedded hardware: it runs unmodified firmware on virtual boards, CPUs, peripherals and the wired or wireless links between them, so firmware can be tested in CI without devices.

What it is
Local cloud emulators
Used for
Automated testing
Type
Open source
Made by
Antmicro
License
MIT (its CPU translation library, tlib, is derived from QEMU and is LGPL 2.1)
Facts checked
24 October 2026
Website Source code

What it is

Renode is a hardware emulator, not a cloud API emulator: what it fakes is the board your firmware runs on. A platform is described in a text file (.repl) that places a CPU, memory and peripheral models such as UARTs, timers, GPIO, I2C sensors and radios at their bus addresses. You load the same ELF file you would flash, start the machine, and the firmware boots: Zephyr, Contiki, U-Boot or Linux, on Arm Cortex-M, -R and -A, RISC-V, x86, SPARC, POWER, Xtensa or MSP430X. Instructions are translated by tlib, a library derived from QEMU’s code, and the peripherals are models in Renode’s .NET codebase. Antmicro lists more than 1,200 supported boards and 800 peripheral models.

It is built for more than one device. Several machines can run in one emulation, joined by simulated wired or wireless links, and a virtual clock keeps them in step: time advances in quanta, and between quanta the nodes exchange data, so a mesh of Bluetooth LE or Thread devices behaves the same on every run. You drive it from the Monitor, an interactive console, or from .resc scripts, and you can attach GDB to any CPU. For tests, Renode ships a Robot Framework keyword library: renode-test starts a headless instance, runs .robot files that load firmware, wait for lines on a UART or press virtual buttons, and writes reports for CI. A GitHub Action, Docker images and portable packages make it easy to run on CI runners.

Renode is MIT-licensed and needs .NET 6 or newer; portable packages for Linux, macOS and Windows bundle the runtime. It can also co-simulate hardware still under design, by connecting HDL models in Verilator, Questa or VCS, or SystemC models, to the emulated system. Antmicro develops it and sells modelling work and support around it. The latest release is 1.17.0, from September 2026.

Why teams pick it

  • Runs the same binaries you flash to the device, so tests exercise real drivers and the real OS rather than a host-compiled build
  • Multi-node systems on one virtual clock: networked and wireless devices can be tested together, with the same timing on every run
  • Made for CI: renode-test with Robot Framework, a GitHub Action, Docker images and snapshots of failed tests
  • Models are text and C#: a new board is often a .repl file that reuses existing CPUs and peripherals

Watch out for

  • A functional simulator, not a cycle-accurate one: it shows what the firmware does, not exact timing or power use
  • Peripheral support varies by chip; the docs warn that your board may need its description or models extended, which Antmicro sells as a service
  • Needs the .NET runtime, and the Python-based test tooling needs Cygwin on Windows
  • It emulates hardware, not cloud services: it won’t stand in for AWS or Azure APIs the way cloud emulators do

Alternatives

What all local cloud emulators have in common →Compare side by side →
FlociOpen sourceA young, MIT-licensed family of local emulators for AWS, Azure, Google Cloud and Oracle Cloud, built as a free drop-in for LocalStack and pitched at AI coding agents.LocalStackCommercialThe best-known AWS emulator: one Docker container that answers more than 100 AWS APIs on localhost:4566, now free only for non-commercial use.MiniflareOpen sourceA local simulator for Cloudflare Workers that runs your code in the real workerd runtime and fakes the platform around it: KV, R2, D1, Durable Objects, Queues, the Cache API and more.

How it fits with other technologies

zephyr_shell.robot: boot Zephyr on a virtual nRF52840 and talk to its shell · text

*** Settings ***
Suite Setup     Setup
Suite Teardown  Teardown
Test Teardown   Test Teardown
Resource        ${RENODEKEYWORDS}

*** Test Cases ***
Zephyr Shell Should Answer On UART
    Execute Command           mach create
    Execute Command           machine LoadPlatformDescription @platforms/cpus/nrf52840.repl
    Execute Command           sysbus LoadELF @https://dl.antmicro.com/projects/renode/renode-nrf52840-zephyr_shell_module.elf-gf8d05cf-s_1310072-c00fbffd6b65c6238877c4fe52e8228c2a38bf1f
    Create Terminal Tester    sysbus.uart0
    Start Emulation
    Wait For Prompt On Uart   uart:~$
    Write Line To Uart        demo ping
    Wait For Line On Uart     pong

# $ renode-test zephyr_shell.robot     (writes log.html, report.html, robot_output.xml)

See it in a real stack

No architecture uses Renode yet. Drop it into the playground and wire it up yourself.Open playground →
Where it came from2017–2026

Antmicro, an embedded-systems company, kept seeing the same problems in IoT projects: development setups that were hard to reproduce across a team, “lack of repeatability, obscurity of the execution environment”, and debugging that got much harder once several cores or devices were involved. It built Renode as an internal tool to design and test such systems, emulating whole SoCs so unmodified binaries could run on virtual devices instead of flashed boards.

On 17 August 2017 Antmicro released Renode as open source, presenting it as a framework for building, debugging and testing software for multi-node device systems. It was already used with the Zephyr Project for a CI environment that tested Zephyr’s networking stack, and integrated with Robot Framework, Jenkins and GitLab CI. Renode 1.1 added Windows in November 2017, alongside Linux and macOS packages.

Support kept growing. Renode 1.14 in September 2023 brought ARMv8-A and Cortex-R52 support plus co-simulation with HDL simulators such as Verilator and Questa. Antmicro also runs continuously updated dashboards that test Zephyr and U-Boot on its supported boards in Renode, and worked with Silicon Labs on 2.4 GHz radio simulation for Bluetooth LE, Zigbee, Thread and Matter meshes. Version 1.17.0 shipped in September 2026.

Why it’s built this way

Emulate whole SoCs and boards, not just CPUs
Firmware talks to timers, UARTs, sensors and radios. Without models of them, the same binary that ships on the device can’t run, and tests would need special builds.
Several machines on one deterministic virtual clock
Bugs in IoT systems often appear only when devices talk to each other. Synchronising nodes in time quanta makes multi-node runs repeatable, which real radios on a desk are not.
Robot Framework as the test interface
Hardware tests mostly read like “wait for this line, press this button, expect that reply”. A keyword-driven framework lets those tests run unattended in CI and produce readable reports.
Reuse QEMU’s translation code for CPUs
Instruction translation for many architectures already existed in QEMU’s code. tlib is based on it, so Renode’s own work goes into peripherals, timing across nodes and testing.

Timeline

  1. 2017

    Released as open source by Antmicro in August; Windows support in 1.1 in November

  2. 2023

    Renode 1.14 adds ARMv8-A, Cortex-R52 and HDL co-simulation

  3. 2025

    Renode 1.16.0 in August

  4. 2026

    Renode 1.17.0 in September

Sources15 · facts checked 24 October 2026

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