The Fuchsia emulator (FEMU) is the default emulator for Fuchsia. FEMU allows you to test Fuchsia components and applications without a physical Fuchsia device.
FEMU is included in the Fuchsia source tree. FEMU is downloaded (or updated) by
jiri, as part of
jiri update or
jiri run-hooks, and is fetched into the
/prebuilt/third_party/aemu directory of your Fuchsia source tree.
You can launch FEMU using
FEMU, AEMU, and QEMU
Due to legacy issues, there may be references to AEMU in the code and documentation.
Debugging Zircon Kernel
If you want to debug the Zircon kernel, you should use
fx qemu instead. Read
Debugging the Kernel using QEMU to learn
more. This is for kernel developers. Most Fuchsia developers do not need to use
FEMU looks and behaves like a Fuchsia device, except that no paving or flashing is required with FEMU.
The features of FEMU include:
- GUI Support: You can run Fuchsia with the GUI (by default) or without
the GUI (using the
- GPU Support: You can run with the host's GPU (by default) with full Vulkan support, or you can choose software rendering using SwiftShader.
- Remote Development: You can use a remote desktop with FEMU over Chrome Remote Desktop.
To see full list of supported flags:
ffx emu start --help
Image and board support
When setting up FEMU using
fx set, FEMU supports the following boards:
With the Fuchsia SDK, FEMU supports pre-built images, including:
ARM64 support (
qemu-arm64) is very limited and not recommended.
ffx --machine product list --version <SDK_VERSION> to see the full list of
products available from the SDK and the corresponding transfer manifests, and
ffx product download <TRANSFER_MANIFEST_URL> to download those products.
--net flag specifies the networking mode for the emulator.
requires a value to indicate which kind of networking to implement.
--net has the following possible values:
tap: Attaches a Tun/Tap interface.
user: Sets up mapped ports through SLiRP.
none: Disables networking.
auto: Checks the host system's capabilities and selects
tapif it is available or
userif a Tap interface is unavailable.
autois the default.
On Linux, FEMU should generally be run with the
--net tap flag that
provides networking through an emulated NIC.
--net tap and
--net user allow the emulator to be discoverable
ffx target list.
--net none disables networking, which causes
the emulator to not be discoverable after running
ffx target list.
If starting the emulator with
ffx emu start --net user, an available TCP
port from the host is picked and forwarded to the emulator's SSH port.
You can manually set the SSH address and use
fx tools to interact
with your emulator by running the following command:
ffx emu start --net user --port-map PORT-NAME:PORT-NUMBER
Replace the following:
- PORT-NAME: The chosen name for the port. An example port name could be
- PORT-NUMBER: The number of the port. An example port number is
Any named ports can be set the same way. The ports that can be mapped are named in the virtual device specification.
To verify that your
fx tool is using the correct port, run the
ffx target get-ssh-address
You should see the SSH address printed next to
To SSH into the emulator, run the following command:
FEMU currently does not run on:
- ARM64 processors, including the Apple M1 processor.
- AMD processors.
Supported hardware for graphics acceleration
FEMU currently supports a limited set of GPUs on macOS and Linux for hardware graphics acceleration. FEMU uses a software renderer fallback for unsupported GPUs.
|Operating System||GPU Manufacturer||OS / Driver Version|
|Linux||Nvidia Quadro||Nvidia Linux Drivers 440.100+|
|macOS||Intel HD Graphics||macOS version 10.15+|
|macOS||AMD Radeon Pro||macOS version 10.15+|
To launch FEMU, complete the Get started with Fuchsia guide.
Alternatively, you can use the Fuchsia SDK and use pre-built system images.
Once you're able to launch FEMU, you can perform the following task: