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 the fx vdl
command, or using the fvdl
command in the Fuchsia SDK.
FEMU is based on the Android Emulator (AEMU){:.external}, which is a fork of QEMU{:.external} – in some instances, such as emulating Zircon, you need to use QEMU instead.
Due to legacy issues, there may be references to AEMU in the code and documentation.
If you only want to emulate Zircon, you must 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 this workflow.
FEMU looks and behaves like a Fuchsia device, except that no paving or flashing is required with FEMU.
The features of FEMU include:
--headless
argument).To see full list of supported flags:
fx vdl start --help
The Fuchsia SDK's fvdl
command supports the same flags as fx vdl
.
When setting up FEMU using fx set
, FEMU supports the following boards:
qemu-x64
qemu-arm64
With the Fuchsia SDK, FEMU supports the following pre-built images:
qemu-x64
workstation.qemu-x64-release
qemu-arm64
ARM64 support (qemu-arm64
) is very limited and not recommended.
On Linux, FEMU should generally be run with the -N
flag that provides networking through an emulated NIC.
Note: Instructions for setting up networking for FEMU is in the Start the Fuchsia Emulator guide.
Without -N
, your emulator is not discoverable using ffx target list
(orfx list-devices
). However, you can manually set the SSH address and use fx
tools to interact with your emulator.
If starting the emulator without -N
(that is, fx vdl start
), an available TCP port from the host is picked and forwarded to the emulator's SSH port. When the emulator launches successfully, an additional instruction, which uses fx set-device
with the correct SSH port, is printed in the terminal output:
fx set-device 127.0.0.1:{{ '<var>' }}SSH_PORT{{ '</var>' }}
Using ths command above, you can manually set the SSH device.
To verify that your fx
tool is using the correct port, run the following command:
fx status
You should see the SSH address printed next to Device name
.
To SSH into the emulator, run the following command:
fx ssh
FEMU currently does not run on:
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.
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 tasks: