Android Emulator Quick Boot

The first time I tried starting the android emulator, I quit it and never used it again. Starting up took about 5 minutes already and it wasn't too responsive afterwards. Now Matthew Casperson posted a nice howto for using the snapshot feature of the android emulator to start it up quickly. Now all I need is a trick to have it running faster as well... But that's not going to happen as long as it relies on qemu to first translate everything from x86 to arm code.  ;)

Being based on Java, you'd think it would be possible to create a much faster emulator by just leaving out the arm cpu emulation. And it seems some people have done that with youwave. Unfortunately, that's windows-only.

Another line of improvements would be to speed up the graphics, as reportedly displayed with impressive results at Google I/O 2011.

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Optimizing Code for Small Size

Many people know the -Os flag of gcc to reduce the code size. Now a while ago Benno posted some tipps to reduce the size of a compiled program for ARM, which give a good hint what to look for in any case. His Summary

"Compile to Thumb instructions.
Use -Os to optimise for space.
Look for unnecessary code.
Look for examples of registers used in the wrong place."

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GnuPlot Cheat Sheet

This wasn't done by me, but it's a good cheat sheet for this nice, but difficult to use piece of software: http://www.gnuplot.info/docs_4.0/gpcard.pdf.

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Must Read Article on the Issues of Ubuntu, Open Source and Linux

http://www.omgubuntu.co.uk/2010/06/many-hands-make-light-work-few-make-it.html

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Resynthesize Tutorial

Resynthesizing can lead to unwanted results sometimes, especially if you have uneven and complicated surfaces. This tutorial shows you step by step how to get the results you want!

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Command Line Output Redirection

Check out this nice article with all the major redirections explained, including the important stderr to stdout redirection.

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Windows Emulator

Check out these great comics by Shane Collinge about a woman writing a windows emulator.

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While I'm busy... List of Ubuntu Blogs

I found an extensive list of ubuntu blogs.

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Limiting CPU Usage of a Program

Interesting article.

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Booting Linux over the Network

Here's a quick how to.

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Circumventing Censorship - Evading the "20th Century's Berlin Wall"

The New York Times presents the status quo in censorship evasion with examples of Iran and China. A quite interesting read. Don't expect a how to, though.

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Some useful CLI Commands

Tuxradar has put up a nice list of useful CLI commands and other tipps. For tip #36 to work in KDE 4, you need to type e.g. =4*5+4. I also recommend tip #49, locate will help you find the file, for me it was /etc/openoffice/sofficerc.

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Make your Firewall Safer with Knockd

Here's a nice howto. It describes how to install, configure and test knockd.

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Linux Kernels 2.6.24 - 2.6.29 Benchmarked (Phoronix)

I've read the newest Phoronix benchmark of all kernels 2.6.24 through 2.6.29 and if you don't follow the link now, I'll spoil it for you in the next paragraph...

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Okay, so besides some normal fluctuations there is a significant speed gain for OpenSSL (+99%) and the OpenCL-backed Graphicsmagick (up to +73% and +80%) and a regression in 7-zip compression (-27%).

Wow - fascinating stuff. I wonder how much potential kernel code optimization has. I still remember the extreme difference between 2.4.x and 2.6.x. I had just bought a new computer because my old one was... getting old. And I felt completely cheated. The new kernel had brought me much more increase in responsiveness and "felt performance" than the new computer (AMD Duron 700 Mhz -> Athlon XP 2500+). If I could I probably would've brought it right back to the store. Well, they don't take returns on self-build computers here.

I really wonder how much difference the intel compiler compiled kernel makes in comparison to gcc. Maybe Phoronix could compare that one, too? Oh yeah "... boost up to 40% for certain kernel parts and an average boost of 8-9% possible" quotes LJ.

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Automatic Backups on Linux (IBM)

Darn them. They just wrote the article I was planning to write and get famous with: Automatic backups over SSH with Keychain and Scp... well, I suggest to use rsync instead. That way it's fast enough to regularly run over internet without even using a lot of bandwidth. (See "Tiny Backup Script with Rsync" under "You might also like".)

By the way, look at their crontab:

34 3 * * * /home/backups/remote_db_backup.sh
34 20 * * * /home/backups/remote_db_backup.sh

Could've simply written:

34 3,20 * * * /home/backups/remote_db_backup.sh

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How the Linux Kernel Works

Tuxradar has a great article entitled "How the Linux Kernel Works". Great for beginners!

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How To Add Knoppix to your USB Stick

If you've got a large USB stick, there's a high chance you will have some space left for installing a current Knoppix on it. That way you can save a few CD-Rs as you need not write a new CD when a new Knoppix comes out.

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Install Daily Fresh Ubuntu Directly over the Web

If you're doing a fresh installation and you don't have a CD downloaded yet, I can recommend the netboot installer. It let's you download and install the freshest packages from a mirror near you. All you need as preparation is e.g. a USB-Stick that boots into grub. Checkout this howto.

Basically all you need to do is copy the kernel "linux" and the initrd "initrd.gz" to your stick. Then boot them from Grub and you can start your installation.

The great thing about it: During the installation you can chose whether to install Kubuntu, Xubuntu, Ubuntu, etc. And you will automatically get the newest available packages right away. There's no need to fetch and install updates after the installation.

And getting the newest packages right away might save you a lot of trouble because of bad packages in the installation cd. And the network installer itself also gets updated regularly.

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Extensive List of Great Ubuntu Repositories

The I been to Ubuntu blog just posted a great and extensive list of excellent Ubuntu repositories.

I especially recommend medibutu: (mplayer, codecs, etc.)
deb http://packages.medibuntu.org/ intrepid free non-free
(install the medibuntu-keyring package)

Wine:
deb http://wine.budgetdedicated.com/apt intrepid main
install the key:
wget http://wine.budgetdedicated.com/apt/Scott%20Ritchie.gpg -O - | sudo apt-key add -

Opera:
deb http://deb.opera.com/opera/ stable non-free

VLC:
deb http://ppa.launchpad.net/c-korn/ubuntu intrepid main

and Google: (Picasa, Google Earth, etc.)
deb http://dl.google.com/linux/deb/ stable non-free
deb http://dl.google.com/linux/deb/ testing non-free # for beta versions like picasa 3
wget https://dl-ssl.google.com/linux/linux_signing_key.pub -O - | sudo apt-key add -

There's a great way to install the missing keys: E.g. for Opera just use this command:
sudo apt-key adv --recv-keys --keyserver keyserver.ubuntu.com 033431536A423791
Replace the number with the one from the error message on sudo apt-get update (without the leading "0x")

Or all in one:
/etc/apt/sources.list.d/custom.list:
#medibuntu
deb http://packages.medibuntu.org/ intrepid free non-free
#wine
deb http://wine.budgetdedicated.com/apt intrepid main
#google
deb http://dl.google.com/linux/deb/ stable non-free
deb http://dl.google.com/linux/deb/ testing non-free
#opera
deb http://deb.opera.com/opera/ stable non-free
#vlc
deb http://ppa.launchpad.net/c-korn/ubuntu intrepid main

And then the keys:
wget https://dl-ssl.google.com/linux/linux_signing_key.pub -O - | sudo apt-key add -
wget http://wine.budgetdedicated.com/apt/Scott%20Ritchie.gpg -O - | sudo apt-key add -
sudo apt-key adv --recv-keys --keyserver keyserver.ubuntu.com 033431536A423791
(...)

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What packages are installed in Debian/Ubuntu

Howtoforge has a nice article on how to install the packages you've installed on another computer. It's written for debian and ubuntu systems, including step by step screen shots for doing it in Ubuntu with Synaptic. Here's how you can do the same thing in CLI(also in that article):

sudo dpkg --get-selections "*" > package_list
and
sudo dpkg --set-selections < package_list && sudo apt-get -u dselect-upgrade

Oh and from the article's comments: The method only works well if you use the exact same version of Ubuntu on both computers. Let me add that it only works at all if you have the same /etc/apt/sources.list and sources.list.d/* files on both computers.

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