Build and Pave Quickstart

This document captures the common-case workflow for building and deploying Fuchsia onto a device using fx development commands. Most such commands have options for less common situations; see fx help <command> for details.

Initial Build and Deploy

The initial build and deploy workflow using fx is as follows:

  1. fx set <arch> Configures the build for : one of [x64, arm64].
  2. fx full-build Builds Zircon, then the rest of Fuchsia.
  3. fx mkzedboot <usb_drive_device_path> Builds the Zedboot media and installs to the USB drive target. See below for notes on obtaining the USB drive device path.
  4. fx pave Starts the bootserver.
  5. Attach Zedboot USB to device and reboot. Zedboot will connect to the host, download the pave image, and pave the device.

USB drive device path

Instructions for determining the correct path to your USB drive are as follows, depending on the host OS. In either case, you can run the command once with the USB drive disconnected, then run again with it connected, to see the difference.

  • Linux users:
    • sudo fdisk -l Drives are usually of the form /dev/sd[x], e.g. ‘/dev/sdc’. Select the drive rather than a specific partition.
  • Mac users:
    • diskutil list | grep external Drives are usually of the form /dev/disk[n], e.g. ‘/dev/disk2’.
    • If you see ‘ERROR: Can’t open /dev/disk[n]: Resource busy' then you will have to unmount the usb drive. For this run hdiutil unmount /dev/disk[n]. If this does not fix the error, try reformating the drive: diskutil eraseDisk JHFSX <name_of_the_usb_stick> /dev/disk[n].

Subsequent Build and Deploy

The workflow for re-building and re-deploying using fx is slightly different:

  1. Check the build waterfall dashboard. Helps ensure that HEAD is in a good state to pull.
  2. jiri update Fetches the latest code.
  3. fx full-build Builds Zircon, then the rest of Fuchsia.
  4. fx setup-macos Sets up firewall rules (Mac users ONLY)
  5. fx serve Starts a development package server on the host.
  6. Boot the device without Zedboot USB attached. Boots the device into its last-paved state.
  7. fx ota Pushes updated packages to the device.

NOTE: If desired, the device can be re-paved using Zedboot USB as per steps 4-5 in the previous section. This is slower, but may be necessary in some cases where the system handles the OTA less than gracefully.


  1. Having ‘.’ in your PATH may cause fx full-build to fail. The script will change the working directory such that it may create conflicts between the commands it uses (e.g. touch) and the binaries in the working directory.