Monday, July 06, 2009

U-Boot hacking -or- The dbox2 can boot from disk!

Thanks to a kind donator, I now own a Nokia dbox2 with IDE interface. (For those that don't know - the dbox2 is a settop box designed for german paytv 10 years ago in a way that its bootloader would only run signed software. A limitation that was put aside by some cool hackers early in this century. Nowadays it usually runs Linux on its 66MHz powerpc CPU, 32MB RAM and 8MB FLASH ROM. Later some cool guys designed an IDE interface that plugs into the memory expansion slot)

The main use of such an IDE interface for most people is to use the box as a video recorder. However, I am already doing this via the ethernet port, wich is more practical for me than a built in disk.

I would have deemed it much more useful if I was able to boot from the IDE drive, since that would make it much easier to try out new experimental code without needing to upgrade the FLASH image all the time (having the known working version in FLASH as a fallback is mandatory for good WAF).

So I pondered the problem and found out, that people had already implemented basic support for the IDE interface in U-Boot (which is used as a "second stage" bootloader), and it could already access and read the disk.

Unfortunately, U-Boot needs to be in FLASH, and this U-Boot would then only boot from disk.

So I have been hacking on making U-Boot actually read multiple boot command lines (and and option which one to boot as default) from a config file in the /var/ partition of the FLASH which makes it pretty easy to switch the device we boot from. It is now actually similar to the boot process of the Tripledragon.

The only thing that's missing now is a driver for the front panel keys, so that you can change the selection on the fly without using a serial console. That's coming next, after the summer vacation ;)

Wednesday, July 01, 2009

Back from Linuxtag 2009

I finally managed to upload my slides to the openSUSE Wiki's Linuxtag 2009 page (I actually had nothing to do with openSUSE this year, but somebody had already listed me on that page and it's actually pretty handy to host the slides there). I also uploaded it to the Linuxtag site, but after experiencing really abysmal organisation this year, I doubt that it will appear anywhere there.

The talk was not that exciting in my point of view - "Netbooks" are, in the end, a pretty boring topic to talk about - but the attending crowd seemed to like it, so apparently it was at least entertaining ;)

The event itself was better than what I had expected from the organisation flaws, I did talk to some embedded people and made many interesting contacts, e.g. with beagleboard guys, peple from the openembedded project and of course the cool hackers from coreboot.

So after a disappointing start, Linuxtag 2009 finally ended pretty successfully for me.