Compile Linux Kernel in Ubuntu with KernelCheck (and Nvidia drivers)

I've always recompiled Linux kernel on all my Linux installations, starting from the kernel sources of the Ubuntu repositories. Then I've heard about the famous 200 lines kernel patch, that I wanted to try, but it doesn't seem to apply to ubuntu linux sources (or at least I had this impression), and I didn't want to try the alternatives.

Then I stumbled upon this nice article about using KernelCheck (which I didn't know) to compile the linux kernel (not from the ubuntu repositories):

a graphical user interface program designed to make the kernel-compiling process as easy as the click of a button. KernelCheck will fetch the latest information from http://www.kernel.org, which hosts the source packages for the Linux kernel, and ask the user which one they would like to compile into a .deb package (with the option of installing the kernel after the compilation).

The article also applies the 200 lines patch, so I decided to give it a try! The articles shows a video, but I'd like to blog about my experience with some screenshots.

Most important, I decided to blog about my experience because of the Nvidia drivers I have on some of my Linux computers, since the first experience with KernelCheck and nvidia drivers was really bad. I think I found a solution to deal with these drivers, so that I can compile the kernel, the patch, and have nvidia drivers work without a problem :)

After you installed kernelcheck, and run it you'll have some screens, and first of all you must retrieve available kernel information:



Then I select the custom compilation




Now, you can select some options.

At this point, it is crucial

• NOT to select the reconfiguration of X server
• NOT to install the nvidia driver
• to select "apply custom patch to the kernel" (if you want to try the 200 lines patch)
• I prefer not to install the kernel package after compilation: I'll do that myself
  

After the download of the needed packages is finished, you'll get a terminal window where you can apply manually the patch (that you can download it from here), and apply it, as it is shown in the screenshot (then you need to close the terminal window)


Then, you'll get the chance to configure the kernel before compilation. Make sure you have all the options you need set (it looks like kernelcheck starts from the current configuration, so, for instance, the processor family is already set as your current configuration).

To enjoy the 200 lines kernel patch, you must enable "Automatic process group scheduling" under "General setup", as shown in the following screenshot:


Then, the compilation starts, and, you know, it might take some time (though for my computer, and configuration it takes less than 1 hour)


Then, you'll be suggested to reconfigure the X server... DON'T DO THIS, and answer no


Then, the kernel deb packages (-image and -headers) will be ready in /usr/src, and you can manually install them.

Note that, during the installation, the Ubuntu kernel utilities will smartly compile and configure the current nvidia modules for you!

Now, reboot and enjoy :)

P.S. I cannot swear my computer is faster now with the 200 lines kernel patch... but I have the impression it is :)

Eclipse icons in menus are not showing in Ubuntu Maverick Linux

I don't like Gnome and I usually use KDE, but on a specific computer I have to use Gnome, and I noted that after switching to Ubuntu Maverick, icons on eclipse menus were not showing anymore.


I asked on some newsgroups with no luck, then on IRC I was pointed to this bug, which solved my issue :)

You need to enable icons in menus with gnome configuration. You find some ways to do that on that bug report, but I simply ran gconf-editor on the command line, and enabled that checkbox:


Now my icons in menus are back :)

Using Compiz in KDE 4

I've been using KDE 4 for some time now, and I was pretty happy with its own desktop effects. However, lately, I started to notice that kwin and xorg process were taking some CPU usage, and with graphic cards such as Intel GMA and ATI, the effects were not so smooth (while in Gnome with compiz they were much better). So I decided to try and use compiz with KDE as well; here's my (positive) installation and configuration experience.

First of all I installed all these packages

emerald libemeraldengine0 compiz compizconfig-settings-manager compiz-kde compiz-fusion-plugins-main compiz-fusion-plugins-extra fusion-icon

Then you found the compiz-fusion application in my KDE menu, in System. Run it, and you can set some configuration options with that icon, in particular, you need to change the window decoration to emerald, and the window manager (to compiz). Then you must select reload window manager.



To keep compiz as the default window manager when KDE starts, you need to change System Settings -> Default Applications -> Window Manager (by selecting Compiz).


Of course, now you can configure compiz settings with its setting manager, but I suggest you to use the simpler configuration manager, simple-ccsm, as illustrated here.

Now enjoy compiz! :)

PhpBibliography 1.1.0

This new release of PhpBibliography features some nice features:

1. First of all, themes are now supported so that the user can create his own theme (which will not be overwritten during phpbibliography updates), see this wiki page
2. icons for known file extensions are shown for uploaded papers (see the screenshot)
3. uploaded papers can be removed during editing
4. the action menu was improved with tooltips
5. search results can be shown also as bibtex

Merging Subtitles in Video Files with DivXConverter

I recently discovered this cool program, DivXConverter, which I didn't find in my Ubuntu distribution (you can download the .deb file, though, and install the required dependencies), but that's really useful and easy to use.

"DivX converter is a simple Mencoder frontend to Produce DivX Player Compatible AVI video format with the ability to merge subtitles . It support many video and audio filters and many presets."

Now, the interesting features I've just used is the ability of merging a subtitle file (typically .srt) into a corresponding AVI file.

Here's what to do (see also the following screenshot):

1. Add the avi file (and select the output folder and the compression, I left the default Normal compression)
   
2. Make sure to select Xvid in the "Video Filters" tab to make sure the resulting avi is compatible with dvd/divx readers (at least the with ones I own)
3. You can leave the default settings for Audio
4. Select the subtitle file (I set ASCII as the encoding)
5. Go back to the main window
6. Press "Convert" and enjoy the resulting AVI file

mounting none on /dev failed: No such device

If you're experiencing this error message at boot in Linux (e.g., after you recompiled the kernel in Ubuntu Lucid)

mounting none on /dev failed: No such device

don't be scared, the boot will continue and there'll be no problem (at least, I read in some posts); I never experienced problems even with this error at boot.
But if you want to get rid of it, just make sure that you have

CONFIG_DEVTMPFS=y

in your .config file of your kernel source directory.

mSoma a Qt client for SomaFM

Andrea Grandi proposed me a few weeks ago to try and develop a client for SomaFM, a streaming radio with near 16 different channels, available for free. Indeed we wanted to try to develop an application for our cool Nokia N900 smartphone. Since this phone is now based on my beloved Qt framework, I accepted with much pleasure.

The really cool thing was that, by relying on the qt-mobility APIs (new Qt APIs for mobile application developers), we could enjoy cross-platform developing: all the code that I wrote for this player was tested and debuged on my computer, as a desktop application. Then, we deployed on the Nokia N900 and tried it there (and it worked seamlessly).

For instance, this are some screenshots of msoma running as a desktop application (in Linux in this case):

And this is a screenshot of the application running in the N900 (taken from Andrea's blog post):

Which is just a recompilation targeting Maemo (with this respect, the Nokia Qt SDK, based on QtCreator, is really helpful when developing).

Of course, this is the very first version of this application, and surely the UI should be different in the desktop application with respect to the cellphone version (in order to be more usable in the mobile devices). But, as it is, it's already enjoyable (but I may be biased ;)

Source code is available on Gitorious and it's always updated with latest version we're working on. If someone want to test the application, it's available in extras-devel repository ("msoma" under Multimedia section) of N900.

In case you want to use it as a desktop application, please remember that you need qt-mobility. I blogged about the installation of qt-mobility in Linux.

We really want to thank, Rusty Hodge, SomaFM's founder, who provided so many details about SomaFM for developing our application (and of course we thank him also for SomaFM itself :)

We look forward to receiving feedback, patches, suggestions, and help! :)

Our maemo profiles:

• Andrea Grandi
• Lorenzo Bettini