Samsung Avila (Tocco) GT-S5230

Here you'll find some informations about tweaking your Samsung Avila (Tocco) S5230. Note that I'm not responsible for any damage to your phone, use at your own risk.

Short review. Pros:

• very good battery life,
• nice big screen (320×400),
• good functionality for low price,
• small size,
• responsive,
• charging through USB port,
• syncing using Active Sync (Google).

Cons (mostly minor):

• inconsistencies in UI (sliding with side keys doesn't always work for lists /ex. Java apps/, reversed sliding direction for Java applications, not all applications follow orientation measured by accelerometer),
• applications (buttons) doesn't always do what you'd expect them to do (you have no idea what's happening now),
• missing arrow keys while editing (or I haven't found them),
• many Internet applications/widgets when the only option to connect to Internet is EDGE,
• lack of Thawte certificate for signing JavaME applications and there's no, official, possibility to install new certificates,
• you can use either USB port or Bluetooth not both at the same time,
• if you change something in widget list you have to set them up one more time because they're all gone,
• screen goes off and doesn't show anything (is the phone on or off), it's a good idea to off backlight and show some basic info (like in Nokia or Sony Ericsson),
• some functionality is locked when battery is low,
• some minor bugs in software (end of file list → delete → lists skips to begging),
• no mini jack connector for headphones,
• buggy (? email) active sync application,
• slow large file handling in Java (possibly not a bug),
• how to display file properties, like size, in file browser?
• Inside Java some screen „clicks” are missed (especially in dialogs like yes/no),
• some dialogs force screen to stay on even if it's not necessary.

Because newest Trekbuddy is signed with Thawte certificate and S5230 is missing that, TB will work as unsigned application but every time you start application system will ask you confirmation to access memory card. Unfortunately it is not possible to install new certificates straight from the phone, you can only view currently installed certificates, to do that go: Menu → Applications → Games and more → More (bottom bar) → Certificates → Third parties. You should see something like this:

To install Thawte (as well as any other certificate) you'll need to download firmware (currently s5230xpik5) and modify part of it. Unpack the firmware, there should be a file with .ffs extension, this is an image of TFS4 filesystem which is FAT compatible. I used WinImage software (shareware, usable for 30 days) to modify the firmware; if you're using Linux loopmount this image:

mount filesystem.ffs /mnt/samsung_image -t vfat -o loop

Please note that I didn't test it under Linux. Next step is to download Thawte root certificates (you may enter anything in the form) and find Thawte Code Signing CA.cer file. But before coping that certificate, remove one of wallpapers or any other unneeded file - for some unknown reason (probably size mismatch) flash software refuses to program if you not free some space before coping the certificate (look in SystemFS\Media\Images). Now copy certificate to Security\Domain3Certs. Save changes and flash new firmware (I didn't use that guide, but it's a good start). Now your phone should have new certificate and Trekbuddy will install correctly:

There's also tkfileexplorer which can be used to view internal memory of the phone but I was unable to find path where certificates could be stored (probably they're copied somewhere else). In settings you must guess COM port number for the phone if you're using USB (try COM3 first).