[ROM] Feiteng A7100 - Spreadtrum SC6820 - Rooted
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:
0. Be sure to have installed the correct drivers. For my SC6820-device I see 5 items in Win7-32bit-device-manager (ADB-Composite, 2 x COM-ports, 2 x USB devices: all without exclamation marks). You can use the drivers from the package folder "SCI-android-usb-driver-jungo-v4-.rar".
1. Disable just in case your Win7 firewall.
2. Launch "ChannelServer.exe" from package folder "CHANNELSERVER" and allow firewall if asked.
3. Start "ResearchDownload.exe" from package folder "ResearchDownload".
4. In ResearchDownload-application chose firmware with first button (for me: 6820_2.3.5_c910_hteng_s5_en_4.0_v01.pac).
5. Be sure that the Baudrate from Win7-Device-Manager-Comports-Settings in CHANNELSERVER equals the Baudrate-settings in ResearchDownload-Settings (second button). I recommend 115.200.
6. Press the Start (Play) button in ResearchDownload-application (third button).
7. Turn off the phone.
8. Keep holding the "- volume" key.
9. Without releasing the button "- volume" plug the usb-cord from phone to Win7 (install the driver if not done before in step 0).
10. The process of firmware-burning should start now in ResearchDownload-application and take approximately 1 Minute. You can release the Vol.Button once it starts.
11. Wait until the firmware-flashing has been finished (A green sign appeares + "Passed" is written in ResearchDownload-application).
12. Remove the battery, wait 20 seconds. Put battery back and turn on the phone (first boot may take a while but not more than 5 minutes).
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.
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.
-- 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).