DCT-4 CPU's and CPU of Nokia 6310

[BlackDragon2003]

I decided to seriously reverse engineer Nokia flashing in order to change some menu options and other things, but I know nothing about CPU of Nokia DCT-4, it's instruction set, it's internal architecture... There are anybody who knows this info and can share it?

[wumpus]

I decided to seriously reverse engineer Nokia flashing in order to change some menu options and other things, but I know nothing about CPU of Nokia DCT-4, it's instruction set, it's internal architecture... There are anybody who knows this info and can share it?
There is little known, as the flash images for DCT-4 are encrypted...

[wumpus]

I've heard about some patched DCT4 firmware images though, does anyone have an idea how they did that when the images are encrypted?

[BlackDragon2003]

Interestingly, if I unsolder the flash chip from phone and read the image from it, it will be encrypted or not?

[kaos]

Interestingly, if I unsolder the flash chip from phone and read the image from it, it will be encrypted or not?

Yes, coz the flashpack is encrypted. I suppose the phone's CPU or sg decodes it in realtime. Even DCT4 phones flash can't be read out by flashers.

DID ANYBODY LOOK INSIDE THE DCT-4 FLASH FILES?
SOME PARTS OF THEM ARE UNENCRYPTED:
8910 - MCU1
6310 - MCU1
6310i - MCU1
7210 - PPM

I've found out that the encrypted blocks has the id "PeaK" in it's header, so it can be easily find where it starts. (TRUE ONLY FOR MCU FLASHFILES, NOT FOR PPM)

BR,
KAoS

[complete_phreak]

Hello,

I am not currently trying to reverse engineeer. Only learn how to reflash my Nokia 7210 myself so that i don't have to wait a week for my Nokia dealer to do it. And maybee also upgrade to a newer version of the formware.

Can anyone tell me a good starting point?

1. I have managed to find a side to download the firmware files (probably the hardest step) but i cannot find a download link for phoenix which the file requires to reflash my phone.

2. Have also managed to download DCT4 flasher 1.7 from the same site but there is no instuction or any info on what type of cable. Can I use the simple unlocking cable to reflash.

[kaos]

You can't use normal cable, you have to build/buy a flasher for dct4 phones. The easiest way is to backup your data and go to a nokia service point with your phone. If you need only sw upgrade, its about 15-45 minutes.