LJ Archive


diff -u: What's New in Kernel Development

Zack Brown

Issue #182, June 2009

An effort to change the license on a piece of code hit a wall recently. Mathieu Desnoyers wanted to migrate from the GPL to the LGPL on some userspace RCU code. Read-Copy Update is a way for the kernel to define the elements of a data object, without other running code seeing the object in the process of formation. Mathieu's userspace version provides the same service for user programs. Unfortunately, even aside from the usual issue of needing permission from all contributors to change the license of their contribution, it turns out that IBM owns the patent to some of the RCU code concepts, and it has licensed the patent for use only in GPLed software. So, without permission from IBM, Mathieu can get permission from all the contributors he wants and still be stuck with the GPL.

Loadlin is back in active development! The venerable tool boots Linux from a directory tree in a DOS partition, so all of us DOS users can experiment with this new-fangled Linux thing. To help us with that, Samuel Thibault has released Loadlin version 1.6d and has taken over from Hans Lerman as official maintainer of the code. The new version works with the latest Linux kernels and can load up to a 200MB bzImage. He's also migrated development into a mercurial repository. (Although not as popular as git with kernel developers, mercurial does seem to have a loyal following, and there's even a book available at hgbook.red-bean.com.) After seven years of sleep, here's hoping Loadlin has a glorious new youth, with lots of new features and fun. It loads Linux from DOS! How cool is that?

Hirofumi Ogawa has written a driver for Microsoft's exFAT filesystem, for use with large removable Flash drives. The driver is read-only, based on reverse-engineering the filesystem on disk. There doesn't seem to be immediate plans to add write support, but that could change in a twinkling, if a developer with one of those drives takes an interest in the project. Hirofumi has said he may not have time to continue work on the driver himself.

Meanwhile, Boaz Harross has updated the exofs filesystem. exofs supports Object Storage Devices (OSDs), a type of drive that implements normal block device semantics, while at the same time providing access to data in the form of objects defined within other objects. This higher-level view of data makes it easier to implement fine-grained data management and security. Boaz's updates include some ext2 fixes that still apply to the exofs codebase, as exofs originally was an ext2 fork. He also abandoned the IBM API in favor of supporting the open-osd API instead.

Adrian McMenamin has posted a driver for the VMUFAT filesystem, the SEGA Dreamcast filesystem running on the Dreamcast visual memory unit. Using his driver, he was able to manage data directly on the Dreamcast. At the moment, the driver code does seem to have some bugs, and other problems were pointed out by various people. Adrian has been inspired to do a more intense rewrite of the code, which he intends to submit a bit later than he'd first anticipated.

A new source of controversy has emerged in Linux kernel development. With the advent of pocket devices that are intended to power down when not in use, or at least go into some kind of power-saving state, the whole idea of suspending to disk and suspending to RAM has become more complicated. It's not obvious whether the kernel or userspace should be concerned with analyzing the sleep-worthiness of the various parts of the system, or how much the responsibility should be shared between them. There seems to be many opinions, all of which rest on everyone's idea of what is appropriate as well as on what is feasible. The kernel is supposed to control all hardware, but the X Window System controls hardware and is not part of the kernel. So, clearly, exceptions exist to any general principles that might be involved. Ultimately, if no obvious delineation of responsibility emerges, it's possible folks may start working on competing ideas, like what happened initially with software suspend itself.

Non-Linux FOSS

Mitch Frazier

Issue #182, June 2009

In our second Upfront installment highlighting non-Linux FOSS projects, we present SharpDevelop. SharpDevelop (aka #Develop) is an IDE for developing .NET applications in C#, F#, VB.NET, Boo and IronPython. SharpDevelop includes all the stuff you'd expect in a modern IDE: syntax highlighting, refactoring, forms designer, debugger, unit testing, code coverage, Subversion support and so on. It runs on all modern versions of the Windows platform.

SharpDevelop is a “real” FOSS project; it's not controlled by any big sinister corporation (and we all know who I'm talking about). It has an active community and is actively upgraded. At the time of this writing, version 3.0 just recently has been released.

Even if you use only Linux, you may be indirectly using SharpDevelop. If you use any Mono programs, they probably were developed using the MonoDevelop IDE. MonoDevelop was forked from SharpDevelop in 2003 and ported to GTK.

SharpDevelop Running on Vista (from www.icsharpcode.net)

LJ Index, June 2009

1. Number of projects listed on sourceforge.net: 161,671

2. Number of new projects registered on sourceforge.net during the first four days of March 2009: 278

3. Number of projects updated on sourceforge.net during the first four days of March 2009: 755

4. Number of projects on sourceforge.net found by searching for “Linux”: 10,222

5. Number of projects on sourceforge.net found by searching for “Windows”: 7,813

6. Number of projects on sourceforge.net found by searching for “Mac OS X”: 5,751

7. Percentage of time you type sourceforget.net rather than sourceforge.net the first time: 98.2%

8. Number of projects listed on ohloh.net: 275,412

9. Number of people listed on ohloh.net: 245,752

10. Start date (in UNIX time) of GCC repository, the third oldest tracked by ohloh.net (November 1988): 594,367,200

11. Start date (in UNIX time) of GNU Emacs repository, the second oldest tracked by ohloh.net (April 1985): 481,183,200

12. Start date (in UNIX time) of BRL-CAD, the oldest tracked by ohloh.net (April 1983): 418,024,800

13. Number of projects listed on freshmeat.net: 45,831

14. Number of users listed on freshmeat.net: 412,744

15. Number of projects listed on code.google.com: 50,000+

16. Number of projects listed on Microsoft's open-source project site codeplex.com: 8,030

17. Number of projects updated on codeplex.com during the first four days of March 2009: 101

18. Number of Google hits for “open source code repositories”: 47,100,000

19. US National Debt as of 03/05/09, 9:36:45am CST: $10,950,269,741,924.01

20. Change in the debt since last month's LJ Index: $174,023,143,132.25

1–6: sourceforge.net

7: Thin air

8–12: ohloh.net

13, 14: freshmeat.net

15: code.google.com

16, 17: www.codeplex.com

18: www.google.com

19: www.brillig.com/debt_clock

20: Math

Linux in a Minute

Shawn Powers

Issue #182, June 2009

Are you new to Linux? Are you an old hand, but want to brush up on your command-line skills? Heck, are you just someone who likes to learn about the tips we dream up here at Linux Journal? Our new video series on LinuxJournal.com brings you new video tips almost every day. Here are some of the topics we've recently covered:

With videos coming out almost every day, you're bound to find something of use in our short one-minute tutorials. Check them out at www.linuxjournal.com/linux-minute.

Delivering Content to Your Desktop with Miro

Shawn Powers

Issue #182, June 2009

I've been a fan of Miro since it originally came out as a program titled Democracy. This open-source, cross-platform project has evolved over the years into an almost perfect example of how to watch on-line media. Miro can play almost any non-DRM video format. What makes it really unique, however, is its ability to retrieve fresh content automatically. It supports the traditional on-line media providers, like Revision 3, but it also adds the ability to subscribe to any RSS feed of videos or even torrents of videos. Miro will download torrent files automatically with its built-in BitTorrent client from any RSS feed you throw at it. Add sites like Hulu.com to Miro's arsenal of content, and you have an almost perfect video-watching experience.

Keep watching this project, because although there isn't yet an interface that's easy to control from a couch, that's a pretty simple change that would make Miro a candidate for your living-room television portal. As it is right now, it's a great addition to anyone's computer desktop. In fact, you can subscribe to Linux Journal's videos and have them delivered to your desktop automatically. I'm not sure if being stuck with my face on your desktop every week is a very good selling point, but at least there isn't a subscription fee. Everything Miro offers, including its software, is completely free. Check it out at www.miro.org.

They Said It

Linux is a cancer that attaches itself in an intellectual property sense to everything it touches.

—Steve Ballmer, June 2001

Will we interoperate with products that come, like Linux, from the Open Source world? Yes, we will. Will we encourage people who want to do open-source development to do it on top of Windows? Yes.

—Steve Ballmer, July 2008

Sun's doing tremendous damage to the project.

—Geir Magnusson Jr, referring to a Java licensing dispute between Sun and the Apache Software Foundation

Religion-themed domains could provoke “bitter disputes” that would force ICANN into “recognizing to a particular group or to a specific organization the legitimacy to represent a given religious tradition”.

—Monsignor Carlo Maria Polvani, in a letter to outgoing ICANN chief Paul Twomey, concerning new Internet domains, such as .catholic, .islam, .muslim and so on, or as The Register called them, the dot god domains.

Just because something doesn't do what you planned it to do, doesn't mean it's useless.

—Thomas Alva Edison

The Web, Making Your Computer Obsolete

Shawn Powers

Issue #182, June 2009

As a video creator, I often try as many different video editing options I can find. I've used video editors on every platform, in every style and every design. I never thought such a resource-intensive process would be able to move to the Web, but as is all too often the case, I was wrong.

If you are like me, you never even considered searching for on-line alternatives for video editing software. You might want to reconsider. I haven't had a chance to test them all, but a simple Google search for “on-line video editor” provides a ton of options. Most of them are completely free, and a few are rather robust. Jaycut (www.jaycut.com), for example, has a look that almost rivals desktop video editing software. Although on-line video editors haven't quite surpassed the abilities of their desktop counterparts, I was more than impressed by how far they've come. Because on-line video editing means you have your tools with you wherever you go, the future of video editing might look very different. It sure beats toting around an external hard drive full of raw DV footage.

Jaycut offers some great editing features right inside your browser.


Katherine Druckman

Issue #182, June 2009

As you read through this year's Readers' Choice Award winners, I'm sure you'll find a few items you'll want to learn more about. You'll discover a wealth of information about almost anything on the list at LinuxJournal.com. With more than 15 years of articles, you'll find what you're looking for, and maybe even learn how some of these tools have progressed over the years.

Head to LinuxJournal.com, and take the search box for a spin. You'll see all your favorites like Python, Nagios and Ubuntu. To get started, check out your favorite game, Frozen Bubble. Shawn Powers gives you a little preview: www.linuxjournal.com/video/better-solitaire-frozen-bubble.

LJ Archive