[Miscellaneous Android Development] Yekdall:
Hi,

I'm opening this post to publish the result of some digging and struggling with a chinese device running the Spreadtrum SC6820 chip.

Details of the phone are can be found on http://www.cellphonemic.com/feiteng-a7100

EDIT: The original ROM is created from base firmware version

mt6515_c910_ht_en_4.0_v01

. Please be careful if your version is different as I have had reports of LCD display issues (greenish colors and ugly pixels). A a sensible approach, please never flash a new ROM without having a backup firmware. Chinese devices often change the chipsets without changing the device version, so it makes it hard to have an universal ROM.

So, let me try to explain the outcome of my work and how to flash the ROM into this device.

First of all, I want to say thanks to pogodancer for his help in my investigation and for providing me the software for flashing the device, as I couldn't get any version to work.

So, getting to the point, I have created 2 versions of the firmware:

Standard Stock ROM - Rooted

This is mostly a copy of the stock rom of the device with the following changes:

- SU binaries included

- SuperUser app added

- Ayu_Sales.apk (CAIVS) application removed - In case you want to know what this app is, check your mobile phone bill. If you find SMS messages sent to chinese numbers (starting by +13) that you have never sent, you now know who to blame ;)

As the ROM is rooted, you can now mount as RW the /system folder and change anything you want.

Link to the firmware: http://www.mediafire.com/?4x9ra4y3e53isjf

Modded Stock ROM - Rooted

This is a modified version of the rom I have done to clean the device from unwanted and chinese software and to add some missing apps. Details are:

- SU binaries included

- SuperUser app added

- Ayu_Sales.apk (CAIVS) application removed

- Go Keyboard (and all its language plugins) removed

- Default Launchers (there were 2) and theme removed.

- ADW Launcher added

- GMail added

- Google Talk added

- Gallery3D substituted by Cool 3D Gallery

And that should be all.

Link to firmware: http://www.mediafire.com/?8i3soi585vjvyfh

Now, for the flashing software, the link to get it is: http://www.mediafire.com/?o9km8vl287ev24j

Instructions for flashing, from pogodancer, are:

Please note that I have flashed the phone it in a Windows XP virtualbox machine and I realized I didn't need the CHANNELSERVER application, so I went directly to step 3.

And that should be all. As usual, use this at your own risk and make sure you are flashing the same device or you could get a nice bootloop.

Cheers.

NB: In case anyone is wondering why flashing the firmware instead of directly rooting it, I just want to say I have tried probably all methods that exist (even the last version of Unlock Root that claims being able to root a MocorDroid2.3.5 like this device). I have also tried to do it manually via an ADB shell, but no exploit seemed to work on this model. It is surprisingly horribly well protected. So, after many days of fighting with it I decided it could be a better solution to unpack the firmware, unmount it, modify it and remount it. And, after many attempts (failed as you may imagine) I have been able to get to these 2 working (and rooted!!) versions of the firmware.

Enjoy!!

-- EDITED --

I have just detected that there are two devices looking very similar with same SC6820 chipset, but made by two different manufacturers:

- Feiteng A7100

- TiangJI A7100

If you happen by chance to have the second one, please DO NOT USE the ROM in this post, as it won't work with your device. The TiangJI device includes a TV antenna that the Feiteng does not, so please verify it before flashing your phone (specially if you don't have a stock firmware backup for your mobile phone).