Development

Rants about application development technologies.

Xperience F2FS

/ Development, Mobile

Starting with early March 2015, CyanogenMod for the whole original line of Sony’s Xperia Z devices support F2FS, a filesystem optimized for flash memory. Tests have shown it to outperform the default ext2/3/4 that we used previously, so definitely a nice thing to have.

However, if you want to benefit from F2FS, you need to manually convert your phone. Be aware that this needs some understanding of how to use ADB and the conversion process will DELETE all you user data/settings!

First, you need to have CyanogenMod 12 or higher installed on your phone, and be using the official recovery. Also, you need ADB installed and ready to use on your computer.

This is how you convert to F2FS:
– Connect your phone via USB and boot into recovery mode
– Open a command line and type “adb shell”
– Type “mkfs.f2fs /dev/block/platform/msm_sdcc.1/by-name/cache”
– Type “mkfs.f2fs /dev/block/platform/msm_sdcc.1/by-name/userdata”
– Reboot the device

Xperience F2FS Read More »

CyanogenMod Fusion

/ Development, Mobile

In January, I’ve been added as a device maintainer for Sony’s fusion3 platform on CyanogenMod. That platform includes the original Xperia Z line of devices (Z, ZL, ZR, Tablet Z, Tablet Z Wifi). Most of my work went into the platform and the 2 tablets, since I actually own one of these. By now, I greenlighted the tablets for CM12, and they are now official CyanogenMod nightlies. , they are my main target of development. The phones will trail a bit, since I need to rely on others to test fixes and features for me, mainly through a thread on XDA.

CyanogenMod Fusion Read More »

Smart phone RIL

/ Development, Mobile

After tinkering with cameras and solar power systems, it was time to play around a bit with Android – in the form of CyanogenMod. After setting up a build environment for my i9100 (a Galaxy S2 in marketing terms), I decided to help figure out a problem with open-sourcifying one of the libraries for it, namely libril (part of the radio interface layer).

This device has a history of freaking out OSS people, and libril was no different, as can be seen in the code review for the library. While the same code would work perfectly fine on similar devices with similar radios, it kept crashing on the i9100 upon dialing out. After some debugging, I found out that the UUS (user-to-user signaling) handling was causing the crash – a MEMMAP SIGSEV error!

Namely, it was memset(&uusInfo, 0, sizeof(RIL_UUS_Info)); that caused the kernel to freak. Intermediate solution? Remove the UUS information, as it is not really mandatory. The question remains: why can’t the phone allocate the (little) memory required for this struct? Might have something to do with heap/stack allocation…

Smart phone RIL Read More »

B,C,D,F

/ Development, Mobile

Today, the updated CHDK code for IXUS 970 has been uploaded to the project’s official source code repository. This new version fixes a problem with the detection of the play mode, and most prominently adds support for firmware revision F, so now all dumped revisions are covered. The firmware addon can be downloaded at the CHDK autobuild server.

B,C,D,F Read More »

Vis Solis

/ Development, Tools

Another piece of contract work completed: this one involved solar power panels and inverters from Austrian manufacturer Fronius. Developed a generic, object oriented data fetching backend and set it up to transmit the data to a database over a HTTP tunnel. One visible outcome of the project can be found here: VS Seeham.
Enjoyed working with the guys responsible for the project and the web frontend development, here’s hoping we will have some future projects together.

Vis Solis Read More »

ARM Success

/ Development, Mobile

Work on the Canon camera is finished by now, with all features seemingly working. As an added bonus, due to a recent update, exposure times can now exceed 64 seconds. If you own a Ixus 970 and want to enhance your camera functionality, pay a visit to the CHDK Downloads page and give it a try.

ARM Success Read More »

1 equals 1?

/ Development

Back to .NET: amazing what you stumble across when writing software. Assume you have 2 arrays and want to compare them:
byte[] array1 = new byte[] { 1, 2, 3 };
byte[] array2 = new byte[] { 1, 2, 3 };
array1.Equals(array2);

All you want to do is determine if the two arrays contain the same elements. The problem with above pseudo-code: it returns “false” as result! The arrays are considered to be different instances of the same data – and thus not equal.

Quick and dirty workaround for small arrays: convert both arrays to a Base64 string and compare their values.

1 equals 1? Read More »

Part Time Assembly

/ Development, Mobile

What if you are a sworn in C and C#/VB.NET coder working mostly on x86/x64 architectures who is looking for a past time occupation? Of course, you go with ARM CPUs, assembly language, and intercepting functions of an embedded system’s innards!
The target of choice: the Canon Ixus 970 digital camera. As mentioned in the article Fiddling with an Ixus, it’s firmware was dumped to contribute it to the community. However, no volunteer stepped forth to port the Canon Hackers Development Kit over. Consequently, the port has been started and shows some success, a beta version is already available for download. Some technical info and the download can be obtained at the CHDK Wiki.

Part Time Assembly Read More »

Fiddling with an Ixus

/ Development, Mobile

In the best spirit of looking beyond Windows/Linux development, the recently acquired digicam Canon DIGITAL IXUS 970 IS seemed to be a good target for some practicing. They sport ARM based processors, which we gathered some experience on when working on dumping tools for the Dreamcast.
The main goal is to help the CHDK community to port their enhancements over to the Ixus 970. Obviously the first step in doing so is to dump the original firmware, and it seems there was no dump of a PAL device with version GM1.00C available yet. Things have changed, and the firmware has been made available to the public by vware!

Fiddling with an Ixus Read More »

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