Plugable UD-160-A driving 1920x1080 display and more, all from a humble Nexus One phone

This setup uses the udlfb DisplayLink Linux driver work from here (git.plugable.com) and a bunch of other components Sven has developed or pulled together, to turn the phone into a full computer with display, keyboard, audio and more. His video of this has gone viral (over 85,000 views). You can see the video and full instructions at Sven’s site. Very cool.

The photo above is of the Plugable UD-160-A Universal Docking Station, in use at Sven’s desk (the dock is laying on its side to better fit in the photo – Sven has removed the weighted bottom stand).

The Plugable dock is perfect for this kind of application with the Nexus One phone — it includes all the USB devices in one place, all with open source drivers. The dock has its own 2.5A AC power (see the USB dual-power Y cable plugged into the front USB A and back USB B ports), along with driving the 1920×1080 monitor (the big DVI cable in the back), and providing ethernet (above the DVI) and audio (in the front – he doesn’t have them plugged in in the pic).

So this all is great for geeks, but when will this work out of the box? Several comments on Sven’s work are messages like “Google! Integrate this into Android now!”

With Google offices near here, and with related USB terminal work on the same Plugable dock being funded as a Google Summer of Code project, it would be great to demo this and get things moving… Whatcha say, Google!?

Last year, he demoed turning your router into a full-fledged computer.

This year, it’s the Google Nexus One phone as a full computer — with attached external keyboard, mouse, display, and more.

The Nexus One demo is using the udlfb Linux kernel module to talk with the DisplayLink device, and it will work with any DisplayLink device, including Plugable’s.

Note the version of udlfb in the 2.6.34 staging tree unfortunately didn’t work for Sven. So he’s now using the latest udlfb from http://git.plugable.com/, which will likely get merged in for kernel 2.6.36.

Also, he used a dual headed cable to get enough power. A powered hub or a docking station/terminal like the UD-160-A won’t need that — it supplies its own power from AC – all the hardware needed is in the one package.

It’s exciting to have all this open source work come together in interesting demos like this.

There was a question recently why udlfb doesn’t use the same compression technique as the Windows drivers. Among other reasons, one is that the RL compression used by udlfb scales down to devices like the ones Sven has been working on — it’s as light as possible on CPU load, while getting decent compression.

Stepping back, it’s clear Apple (and now Microsoft) are making a mistake by limiting the hardware ecosystem around their devices. Android and the other Linux variants have an opportunity here — and considering the Apple juggernaut, they definitely need every advantage.

Sven’s demos show how powerful these scenarios can be. The hardware is ready. Devices like Plugable’s are designed with these scenarios in mind. Now we need to get the software refined and included in standard distributions, so normal consumers can take advantage of all the possibilities and benefits here.

The goal of their project was to get an embedded platform working on Centos 5.3. You can read more in their release note for the work.

To make the contributions easier to diff, they’ve been checked into a git branch from a (best guess) of the code Endurance started from.

The changes are available here for the kernel driver and here for the X server.

To actually build it, you may need their full package.

It’s unclear what of these changes might get picked up, as things have moved on since. One of the main features of this code is providing a default EDID blob in udlfb. The plan for udlfb at this point is to allow the edid sysfs interface of udlfb to be written to, to allow (and give responsibility) to a user-mode entity to supply a default edid, if one isn’t available from hardware.

Thanks again to Endurance for being diligent about contributing changes back.

We’re very excited about the Google funded project to refine USB multiseat on Linux, with the winning proposal from Lucas Nascimento Ferreira at the Federal University of Parana in Brazil.

In addition to providing mentoring, Plugable is also providing donated hardware for this project. Two Plugable Universal Docking stations with recent enhancements for use as a terminal, were just picked up by Lucas in Brazil today. By next month, we expect to have updated versions of the UGA-125-HUB for terminal use to send down.

For those interested in learning more and potentially following Lucas’ work:

• Google’s SoC 2010 Timeline
• Lucas’ winning USB Multiseat Proposal

And we’ll post periodic status updates here.

We do this because we know you use a mix of machines, or may be thinking about switching one way or another. And when you invest in a collection of USB devices, you want them to be useful beyond your current computer. That’s what we expect, too.

All this activity can get a little noisy, though. A little too much information.

That’ll be especially true for some exciting but technically involved work that’s happening over the next few months on Linux with the Google Summer of Code project for USB multiseat, which makes use of some of our Plugable hardware.

So if you’re interested in just one platform or another, here is a way to get just the news that you care about, and get rid of the rest of the noise:

•  Subscribe – Windows News From Plugable
•  Subscribe – Mac News From Plugable
•  Subscribe – Linux News From Plugable

And for those wanting an even more customized view — just append /feed to the tail end of any category view on the site, to get an even more specific feed, if you’re interested.

Linux hasn’t had that support — it would try to set the highest mode the monitor is capable of, often resulting in a black screen. Especially common for the DL-125 chip, with its mode limits of 1440×900/1280×1024.

That’s a shame because the DL-125 chip is a smart choice in many cases – by limiting itself to those lower modes, it stays more consistently within the limits of the USB 2.0 bus, resulting in more consistent performance.

So coinciding with the launch of Plugable’s DisplayLink DL-125 based products (UGA-125 and UGA-125-HUB), changes have been implemented to bring Linux roughly up to the level of Windows and Mac in this area for DisplayLink devices. This also helps devices like the UD-160-A when running on monitors greater than its limit of 1920×1080.

The kernel framebuffer driver udlfb has been enhanced to read the resolution limit from the firmware descriptors of the device, and adhere to it.

On the X server side, we needed a driver which would limit itself to the resulting reduced mode list. Unfortunately, the existing displaylink X server reads EDID directly, and assumes the adapter can do whatever the monitor can do.

We’ve been wanting to get rid of the need for a displaylink-specific X server, and the standard xf86-video-fbdev driver runs with the best existing mode, rather than trying to set a higher one in EDID. So this was a good trigger for converting over.

So xf86-video-fbdev has been enhanced with X Damage protocol support, ported from Roberto’s displaylink driver. This is still a little in-flux from an interface perspective, but from a functional perspective it’s done and fully performant.

So it’s now possible to run with a modified generic fbdev driver, which talks to udlfb, with full performance and without needing defio (although there’s also some good news in the defio space, which will be posted about later).

You can grab the latest udlfb kernel module with a “git clone http://git.plugable.com/webdav/udlfb”. Compile with “make && sudo make install && sudo depmod -a”

And you can grab the latest modified xf86-video-fbdev with a “git clone http://git.plugable.com/webdav/xf86-video-fbdev”. Compile with “./autogen.sh && make && sudo make install”

You’ll need a very recent xorg-macros version (1.4), which in package “sudo apt-get install xutils-dev”

To use the new X server, you must turn on the new “ReportDamage” option to fbdev. Modify your existing xorg conf like this:

Section "Device"
  Identifier "dl"
  Driver "fbdev"
  Option "ReportDamage" "true"
  Option "fbdev" "/dev/fb0"
EndSection

And you should be all set to go. This new X server should work with the existing udlfb in the staging tree of kernel 2.6.31+ for now, as it’s re-using the same original ioctl. But may require modeset changes that are only in 2.6.34+.

The main focus is USB multiseat, and the details are on the xorg wiki for SoC 2010

With all the pieces that are just coming together now, there is a potential here to do a project with huge impact, without a massive amount of engineering. There is already a very solid proposal coming from a student in Brazil who has previously been involved with the MDM multiseat project.

Google’s deadline for applications is now just a few days away: April 9th.

If there’s interest from other parties, we’ll get everyone talking – or there are other related proposals that we might be able to get in at the last minute. Foremost among those is conversion of the DisplayLink USB driver udlfb and matching X server from a fbdev driver to the KMS model.

Here’s the basics of the USB multiseat opportunity:

USB Multiseat Refinement

Linux Multiseat setups have potential to significantly reduce the cost of computing, but can be hard to configure. Some progress has been made on USB multiseat, where all components of the “terminal’ (display, keyboard, mouse, and more) are on USB, so configuration can be fully plug and play – you can just assume that all devices on the same USB hub constitute a terminal.

Some early prototypes of this are working (see http://plugable.com/2009/11/16/setting-up-usb-multiseat-with-displaylink-on-linux-gdm-up-to-2-20/). The underlying kernel drivers and X servers are largely in place.

But recent changes to the X Server, ConsoleKit, and other components open the possibility for a cleaner implementation.

This SoC project would constitute the refinement/creation of configuration scripts to enable a standard Linux or *nix computer to automatically launch additional seats when a USB terminal is plugged in

* udev rules to detect hubs/devices which should be collectively treated as terminals
* udev attributes to label the set of devices with a common seat id
* udev triggers for on-demand generation of the appropriate Xorg config files, to allow seats to coexist with the primary display/devices.
* ConsoleKit scripts to launch independent GDM/X sessions for each USB terminal seat
* InputClass rules to cause the primary X session to ignore multiseat-assigned devices, and the appropriate seat to use them
* udev rules and X init scripts to grant access to audio, storage, and other devices to the person logged into the matching seat

The one-sentence goal of this project: To make USB multiseat fully plug and play for the end-user, and ready for any distro to safely and cleanly drop in at any time.

Know any aspiring software engineering students that might be interested? Check SoC info from Google and the SoC guidelines from xorg.

There will still be some bugs and issues to resolve — but this release has most of the features, specifically related to input handling and udev-based dynamic configuration, of a more solid USB multiseat solution.

In short:

• udev rules, which already can detect a grouping of USB devices that constitute a terminal, can now tell X to ignore or use particular devices more easily through udev attributes and more dynamic/independent xorg.conf.d scripts.
• udev is now the default configuration mechanism (the torch has been passed from the less flexible hal)

So the challenges to explore are now more in the area of ConsoleKit integration and whether we can use these new capabilities support not just pure-USB multiseat setups, but also a mix of seats with PCIe attached graphics, and with fully USB seats.

You can read more about the new 1.8 configuration features which multiseat will use at Peter Hutterer’s blog.

And read more about the RC itself at Phoronix

We use NTFS-3G on Mac OS 10.4 here, in combination with the Plugable USB 2.0 SATA All-in-one Storage Dock and large TB+ SATA drives. Along with built-in NTFS support on Windows XP and up, and all recent Linux distros, this lets us easily swap a single USB cable between Windows, Mac, and Linux and have all three be able to read and write the drive(s).

Overall, this is a good solution for developers who have to span multiple platforms, for people who use boot camp to switch between Mac and Windows, or for increasingly common multi-platform offices that are using external storage docks for backup.

And it’s nice having a both an open source and a (better performing) commercially supported option.

It used to be that the venerable FAT32 filesystem was best way to format a drive to make sure you could easily read and write it from Windows, Mac, and Linux. But FAT32 has some limits that are especially problematic for today’s large drives 1 TB and up:

• Hard limit of 4GB on any individual file (think home movies of 30 mins or more)
• FAT32 needs large cluster size for large disks – which means wasted disk space in the case of many small files
• Partition size limits that can get as small as 32GB, and certainly hit at 2TB

There are various ways to read and write filesystems native to one OS on another. But there are also lots of pitfalls. All things considered, NTFS is the best compromise today.

For more background:

• Windows FAT32 filesystem limits
• Windows NTFS filesystem limits
• Mac HFS+ filesystem limits
• Linux Ext filesystem limits