Sony Vaio Z21 DSDT fun

My wife urged me today to work on her new Sony Vaio Z21, which is, as anyone able to use Google will know, not particularly well supported by any recent Linux distribution. This is not exactly due to the completely fancy hardware components, rather by the completely undocumented methods of how to switch them on and off.

As an example, the Z21 has a builtin 3G modem, an Option Globetrotter, which is connected to an internal PCIe slot, which means it should just show up on the USB bus. Unfortunately it does not, not under Linux at least. The reason is that Sony chose to switch the modems power supply through an embedded controller chip on the motherboard. This embedded controller is nonstandard and therefore not managed through standard ACPI methods you would find under /proc/acpi, however there is a small kernel module, sony-laptop.ko, which provides an interface to some of the Sony proprietary device functions. The Z21 is unfortunately not supported yet by this module.

Well, it was not difficult to make the module detect the Z21, but the fun just started at this point: None of the functions provided by this module worked. Nada. Zero. OK. Turned out that while the Z21 contains the same "Sony Notebook Controller" as other Vaios, it did not react to any of the known ACPI method calls. So, I started looking deeper into the DSDT. I had never done that in depth before, but looking at the decompiled DSDT ASL, knowing that the DSDT is really not a table but rather byte code, it wasn't difficult to understand that the "SN07" method of "SNC" device was the key to switching the modem on and off. After traversing several levels of If/Else statements I found that calling "SN07" with 0x9f070803 as argument switches on the 3G modem, while 0x00000803 turns it off again.

Unfortunately this is not the end of the story. While the modem is now accessible via USB and even recognized by the hso.ko driver module, and even while we're able to talk AT commands via ttyHS0, we have yet to make the first data connection.

The biggest challenge will however be to understand the weird inner workings of the graphics adapters. The Z21 has two of them, an Intel GM45, and and some Nvidia with a name that I currently cannot remember. Under Vista you can dynamically switch between them, and unfortunately the BIOS lacks any preset, so when you cold boot into Linux, both of them are active which completey confuses the drivers and disables direct rendering. I know the answer is somewhere inside the DSDT devices and methods, but it's hard to understand this from reading the disassembled bytecode, without comments or sensible variable names.

Digital photography, a new passion..

Ready!
Originally uploaded by thinkfat

Since we got our new digital camera I have been using it quite regularly and I got very much interested again in digital photography and everything around it. I used to shoot lots of photos when I inherited my grandfathers Cosina SLR, despite the tedious act of having the film developed and paying for prints just to throw lots of them away.

I don't quite remember why I never picked up a digital SLR camera when they became fashionable, but they were quite expensive back then and anyway I spent most of my money (and most of my time) on amateur radio equipment. Today the situation has changed. DSLR cameras today are mass market products, not just for photography enthusiasts.

So, I familiarized with the Lumix G1 quickly and today I carry it with me almost constantly. The photo in this blog post links back to my flickr account, you're welcome to have a look at some results of my early ventures into digital photography.

Interestingly, this camera got me back to KDE programming again. Of course I started using various 'K' programs like KPhotoAlbum or DigiKam to keep track of my growing collection. And sure enough, once you start using a 'K' program, you find lots of small annoyances that demand fixing. So I hacked kflickr to upload resized pictures with an adjustable quality instead of some default value, digikam to recognize the lens description of the Lumix G1, the flickr export plugin to allow uploading to the photostream only instead of requiring a set and I'm now trying to automatize lens defect correction using information embedded in the RW2 files this camera generates when shooting 'RAW'.

First motobike trip of the year

p1020151.jpeg
Originally uploaded by thinkfat

If the motorbike virus has you, somehow it's not a question of convenience any more to go for a quick ride or not. So right after lunch today we took out our bikes for the first time this year. It was sure a bit chilly still at 5°C but with the right clothing it was bearable. We drove up to Neunkirchen, had a coffee and apple pie and went back home again.

I also took the opportunity to see if the camera setup I envisioned for our summer vacations would work out, and I'm happy to report that the Lumix G1 fits nicely into the tank pack as planned and is easy enough to operate while on the bike.

I also experimented with the geotagging feature of digikam, which worked quite nicely. I downloaded the trip log from my GPS after the ride and told digikam to correlate the images I had taken. It added a set of tags to the EXIF information that show the location where the photo was taken - well, to be precise, the location where the GPS receiver was when the photo was taken, but since it's mounted on the bike, that's not going to be too far off.

Now if I only could get flickr to consistenly import the location data. It's working only sometimes and I don't know why.

Lumix G1 - some first pictures

Of course the weather did not improve over the weekend and there wasn't much point in going outside "hunting". But this night the temperature fell below freezing point and today morning everything outside had a nice glaze of frost. I did a quick walk through the garden to take a few pictures. This rose came out particuarly nice. I didn't play around with the program, probably I could have achieved a more blurred background with a wider aperture:



Another nice shot, some latent Hibiscus buds:


I'm hoping for nicer weather now ...

New Gadget: Panasonic Lumix G1

So eventually, after a one-day intermezzo with the D40 (which is definitely a very nice camera!) we settled on the Panasonic Lumix G1. I didn't have much time to play with it yet, but it's really quite a nice camera. It's tiny, and solidly built. It's a huge difference to the D40, which feels a lot more plastic-y. But that's somewhat expected, after all the D40 costs about half of the G1.

I've shot a few test photos indoors and it's not a bad performer there. The view finder is a bit noisy in low light but it doesn't influence usability much. Still, if it gets really dark the frame rate of the view finder decreases a lot. Not sure why, I guess the camera then averages across several frames to keep the noise down.

The auto focus is fast. I have no comparison to DSLR cameras in the same price range, but it's easily as fast as the D40 (which probably doesn't say much).

The flashlight seems a bit weak. Where the D40 tended to overexpose, the G1 is more into underexposing images shot with the flash. Might be a configuration issue, I haven't figured out all the settings yet.

I'm very pleased. I'll try to make a few outdoor shots during the weekend. Hope the weather improves over night, it just started raining again.