1. Computers
  2. Display Drivers
  3. Graphics Cards
  4. Memory
  5. Motherboards
  6. Processors
  7. Software
  8. Storage
  9. Operating Systems


Facebook RSS Twitter Twitter Google Plus


Phoronix Test Suite

OpenBenchmarking.org

Wayland's Weston Brought To The Raspberry Pi

Wayland

Published on 07 November 2012 04:46 PM EST
Written by Michael Larabel in Wayland
1 Comment

Pekka Paalanen has published initial patches that allow Wayland's Weston reference compositor to run from the popular low-cost Raspberry Pi ARM computer.

Pekka's patches for Weston allow for a configurable Weston back-end at build time, contains a small fix to the OpenGL ES 2.0 support, and introduces a Raspberry Pi back-end for the compositor. The "RPI" back-end is around 2,000 lines of new code for Weston.

With the open-source Raspberry Pi graphics driver being lackluster, the Wayland/DRM back-end isn't applicable here so a Raspberry Pi specific back-end was written for Weston. Here's Pekka's description for how this new back-end functions:
This backend uses the DispmanX API to initialise the display, and create an EGLSurface, so that GLESv2 rendering is shown on the "framebuffer". No X server is involved. All compositing happens through GLESv2.

The created EGLSurface is specifically configured as buffer content preserving, otherwise Weston wouuld show only the latest damage and everything else was black. This may be sub-optimal, since we are not alternating between two buffers, like the DRM backend is, and content preserving may imply a fullscreen copy on each frame.

Page flips are not properly hooked up yet. The display update will block, and we use a timer to call weston_output_finish_frame(), just like the x11 backend does.

This backend handles the VT and tty just like the DRM backend does. While VT switching works in theory, the display output seems to be frozen while switched away from Weston. You can still switch back.

Seats and connectors cannot be explicitly specified, and multiple seats are not expected.

Udev is used to find the input devices. Input devices are opened directly, weston-launch is not supported at this time. You may need to confirm that your pi user has access to input device nodes.

The Raspberry Pi backend is built by default. It can be build-tested without the Raspberry Pi headers and libraries, because we provide stubs in rpi-bcm-stubs.h, but such resulting binary is non-functional. If using stubs, the backend is built but not installed.

VT and tty handling, and udev related code are pretty much copied from the DRM backend, hence the copyrights. The rpi-bcm-stubs.h code is copied from the headers on Raspberry Pi, including their copyright notice, and modified.
These Weston patches are currently floating on the Wayland-devel list.

About The Author
Michael Larabel is the principal author of Phoronix.com and founded the web-site in 2004 with a focus on enriching the Linux hardware experience and being the largest web-site devoted to Linux hardware reviews, particularly for products relevant to Linux gamers and enthusiasts but also commonly reviewing servers/workstations and embedded Linux devices. Michael has written more than 10,000 articles covering the state of Linux hardware support, Linux performance, graphics hardware drivers, and other topics. Michael is also the lead developer of the Phoronix Test Suite, Phoromatic, and OpenBenchmarking.org automated testing software. He can be followed via and or contacted via .
Latest Linux Hardware Reviews
  1. Acer B286HK: A 28-inch UHD LED 4K Monitor For As Low As $350
  2. Intel Xeon E5-1680 v3 & E5-2687W v3 Compared To The Core i7 5960X On Linux
  3. Intel 120GB 530 Series SSD Linux Performance
  4. Btrfs/EXT4/XFS/F2FS RAID 0/1/5/6/10 Linux Benchmarks On Four SSDs
Latest Linux Articles
  1. Mesa Git Yields Performance Improvements For Newer AMD GPUs
  2. Apple OS X 10.10 vs. Ubuntu 14.10 Performance
  3. Mesa 10.5-devel Brings Some Intel Haswell HD Graphics Changes Over Mesa 10.3
  4. NVIDIA vs. Nouveau Drivers With Linux 3.18 + Mesa 10.4-devel
Latest Linux News
  1. NVIDIA Posts Tegra Gallium3D Patch For K1+ Support
  2. Ubuntu 14.10 MacBook Air Tests With Linux 3.18, Mesa 10.5
  3. AMD Richland APU Support Added To Coreboot
  4. 2014 Holiday Shopping Reminder, Happy Thanksgiving
  5. Python 3 Support Added To The GNOME Shell
  6. ReactOS Lands Its New Explorer Shell
  7. Weston's IVI Shell Sees New Version
  8. IMP Launches As Another Open-Source Computer Attempt
  9. Git 2.2.0 Released With 550+ Changes
  10. GNOME 3.15.2 Released
Latest Forum Discussions
  1. Updated and Optimized Ubuntu Free Graphics Drivers
  2. Hurrican SDL Port
  3. Roadmap to Catalyst 14.10 ?
  4. how to configure module phoromatic ?
  5. PulseAudio 6.0 Is Coming & Other Linux Audio Plans For The Future
  6. Debian Developer Resigns From The Systemd Maintainership Team
  7. Cant get working Kaveri APU - A10-7850k
  8. Script for Fan Speed Control