[qemu-edu] Replace hard-coded path with search.

Update qemu-edu driver client and system test to recursively search
devfs for the matching device file instead of relying on the fully
qualified path as a hard-coded constant.

Bug: 114888
Change-Id: Ic7ef84e0d005b2f09440e3064bcdb897d2cb42b8
Reviewed-on: https://fuchsia-review.googlesource.com/c/sdk-samples/drivers/+/758724
Reviewed-by: Suraj Malhotra <surajmalhotra@google.com>
Reviewed-by: Wayne Piekarski <waynepie@google.com>
Commit-Queue: Dave Smith <smithdave@google.com>
2 files changed
tree: 5eacde276f80b52b756059d5db028bea84962b64
  1. scripts/
  2. src/
  3. third_party/
  4. tools/
  5. .bazelrc
  6. .clang-format
  7. .gitignore
  8. .gitmodules
  9. AUTHORS
  10. CONTRIBUTING.md
  11. driver-samples.code-workspace
  12. LICENSE
  13. OWNERS
  14. PATENTS
  15. README.md
  16. WORKSPACE.bazel
README.md

Fuchsia samples using the Fuchsia SDK

This repository contains instructions and source code to build, package and run Fuchsia samples using only the Fuchsia SDK.

Requirements

  1. Make sure this repository has the required submodules:

    git submodule update --recursive --init
    
  2. Run the bootstrap script that downloads the appropriate Bazel binary:

    scripts/bootstrap.sh
    
  3. Ensure that there are Fuchsia SSH keys in your host machine. You will need them for running the Fuchsia emulator.

     [[ -f "${HOME}/.ssh/fuchsia_ed25519" ]] || ssh-keygen -P "" -t ed25519 -f "${HOME}/.ssh/fuchsia_ed25519" -C "${USER}@$(hostname -f) Shared SSH Key for Fuchsia"
    
     [[ -f "${HOME}/.ssh/fuchsia_authorized_keys" ]] || ssh-keygen -y -f "${HOME}/.ssh/fuchsia_ed25519" > "${HOME}/.ssh/fuchsia_authorized_keys"
    

Build, run and test the samples

The repository is ready to build the samples.

Note: in order to use an SDK produced by a local Fuchsia platform tree, you can set an environment variable named LOCAL_FUCHSIA_PLATFORM_BUILD as described in https://fuchsia.googlesource.com/sdk-integration/+/0503b02c059a6de76242280b467898358ba30ae3

  1. If using an emmulator:

    1. Fetch the system images

      tools/ffx product-bundle get workstation_eng.qemu-x64 --repository workstation-packages
      

    Note: if the command above fails with an error message that states that there are multiple product bundles with the same name, you can either specify the full qualified URL as printed in the error message, or you can wipe out old and unused product bundles in the pbms storage, which should be located in ~/.local/share/Fuchsia/ffx/pbms on Linux, or ~/Library/Fuchsia/ffx/pbms on MacOS.

    1. Start the emulator

      tools/ffx emu start workstation_eng.qemu-x64 --headless \
         --kernel-args "driver_manager.use_driver_framework_v2=true" \
         --kernel-args "driver_manager.root-driver=fuchsia-boot:///#meta/platform-bus.cm" \
         --kernel-args "devmgr.enable-ephemeral=true"
      
    2. The product bundle comes with on-demand packages in a separate repository. Use the following command to register it with the emulator:

      tools/ffx target repository register -r workstation-packages --alias fuchsia.com --alias chromium.org
      
  2. If using a physical device like a Pixelbook Go:

    1. Fetch the system images

      tools/ffx product-bundle get workstation_eng.qemu-x64-dfv2 --repository workstation-packages
      
    2. Prepare and connect the Pixelbook Go, by flashing and/or paving it (not covered here), and connect using Ethernet.

    3. The product bundle comes with on-demand packages in a separate repository. Use the following command to register it with the device:

      tools/ffx target repository register -r workstation.qemu-x64-dfv2 --alias fuchsia.com --alias chromium.org
      
    4. Update (OTA) the device to the version of the SDK:

      tools/ffx target update check-now --monitor
      
  3. (optional) watch the device log in a separate window

    tools/ffx log
    
  4. Load the sample drivers

    Now you are ready to register a driver. Starting with the example driver:

    First, let's confirm that the driver is not loaded:

    tools/ffx driver list | grep example_driver
    

    The command above should not return any driver named “example_driver” because it has not been registered.

    Now register the driver:

    tools/bazel run --config=fuchsia_x64 src/example_driver:pkg.component
    

    The driver now should show in the list of loaded drivers:

    tools/ffx driver list | grep example_driver
    fuchsia-pkg://bazel.pkg.component/example_driver#meta/example_driver.cm
    

    You can also watch in the log to see if the driver is loaded correctly. The ffx log window should show a message similar to:

    [88.961][bootstrap/driver_manager][driver_manager.cm][I] Loaded driver 'fuchsia-pkg://bazel.pkg.component/example_driver#meta/example_driver.cm'