Possible Gen 4 Unbricking Using Amlogic Flash Tool

[tpaine]

Coby generation 4 devices use an amlogic cpu. Amlogic provides a flash tool to reload the firmware on these devices from a desktop pc. There is some documentation of the process, but it requires a special image specific to the device.

Researching the issue, there is documentation of the process for other devices. Generating a coby device specific image file is the goal of this thread.

This thread got me interested:

http://www.androidtablets.net/forum...d-bricked-novo-10-hero-have-one-question.html

This thread at slatedroid has more info:

Amlogic Low level flashing tool - SlateDroid.com

The goal is to create recovery images for gen 4 devices (perhaps thu firmware dumps) as a last chance tool like livesuite is for gen 3 devices. As coby is gone, this may be the last chance for some gen 4 devices.

update- Vampirefo has posted a thread with instructions for Amlogic cpu's here:

http://www.androidtablets.net/forum...3-7035-7065-7060-so-repair-tablet-sdcard.html

Anyone interested in repairing their tablet should read that thread for more info.

 

[tpaine]

No coby specific files yet found in my searches, but here is a link to a discussion of the process for some Ainol devices with Amlogic CPUs

Using AML Flash - SecureInstrument

http://www.slatedroid.com/topic/35629-how-to-unbricking-the-elf-ii/page__p__391280#entry391280

Does anyone know if the u-boot.bin file is the bootloader ? I know uImage_recovery is the recovery image. Does the bootloader look at the ex-sd card first on boot ?

It seems if one could load the bootloader, a recovery from ext-sd would be possible.

 

[vampirefo.]

You aren't going to find any files for Coby tablets. All files will either have to be pulled from device, made or used from a similar device.

Sent from my SPH-D710 using Android Tablet

 

[vampirefo.]

The post by fards is the most interesting one, seems he used open source generic version that seems like the best direction to start in.

Sent from my SPH-D710 using Android Tablet

 

[tpaine]

The trick from the hero thread is to get the cpu in usb recover mode. As Vampirefo pointed out, he probably had a bad/wrong bootloader. He had to short 2 pins on the motherboard. This puts the tablet in usb recover mode, allowing the flashing of a new bootloader from the desktop without access to adb.

Looks like fards did much of this thru linux...

 

[vampirefo.]

Yes, the Linux part is what most interested me, I am not really interested in using Windows method.

Sent from my SPH-D710 using Android Tablet

 

[tpaine]

I'm trying to move to linux. It sure made rooting the 8065 easier. took me a while to get the drivers right in windose. Still need it for livesuite, tho.

That what makes this technique desireable. We can experiment without too much fear.

 

[vampirefo.]

I'm trying to move to linux. It sure made rooting the 8065 easier. took me a while to get the drivers right in windose. Still need it for livesuite, tho.

That what makes this technique desireable. We can experiment without too much fear.

I think I got it figured out, all the files needed are on the tablets, but the config_progress.xml my guess on that one we would just use one already made.

the Amlogic Low level flashing tool simply flashes the bootloader, then the bootloader reads the sdcard and finds either a recovery.img or boot.img, if it finds a recovery.img the recovery can be booted, if it finds a boot.img then the tablet can be booted either from regular mode or from sdcard, if system and data are installed on sdcard.

 

[tpaine]

I have another broken 8065 on the way (bad display, touch ok). Gonna make 1 good one. The other will make a good test device.

I'm tempted to try a boot.img in the flashtool imager. I;ve booted a stock recovery from sd (renamed to uImage_recovery). Can this be done with the boot.img renamed to uImage_recovery ?

Luckily, ainol has provided several AML flashtool images we can look over for the config_progress.xml files.

 

[vampirefo.]

I have another broken 8065 on the way (bad display, touch ok). Gonna make 1 good one. The other will make a good test device.

I'm tempted to try a boot.img in the flashtool imager. I;ve booted a stock recovery from sd (renamed to uImage_recovery). Can this be done with the boot.img renamed to uImage_recovery ?

yes rename boot.img to uImage_recovery it will boot.

 

[vampirefo.]

Ok I made a recovery sdcard, I like it, works as it should.

The method I used is done in Linux I guess it can be done in windows also, someone with windows would need to post the equivalent of dd and hexeditor program.

I will just link to the blog I used.

Aditya Gilra: Unbricking & Upgrading the Gadmei E8HD

 

[tpaine]

Ok I made a recovery sdcard, I like it, works as it should.

The method I used is done in Linux I guess it can be done in windows also, someone with windows would need to post the equivalent of dd and hexeditor program.

I will just link to the blog I used.

Aditya Gilra: Unbricking & Upgrading the Gadmei E8HD

Great news on your recovery sdcard. Just now skimmed the linked blog, Needs more study, later today I hope.

I won't spend any time trying for a windows solution now when the linux method works. Gparted works period. Later the windows method can be worked.

 

[tpaine]

Posting for example purposes only sample.aml (taken from the update package from Vamps link above)

--update_package=/sdcard/g11refE8-ota-eng.bestidear.zip
--update_patch=/sdcard/patch_gadmei_e8t3cn.zip
--wipe_data
--wipe_cache
--wipe_media

This file is part of the sdcard update for a non coby amlogic based device. Its named factory_uodate_param.aml- Possible template for automated repair/reinstall/upgrade?

Following the upgrading and unbricking link, created a bootable ext-sd with bootloader and boot.img !

Vampirefo is working on a generic recovery for use on ex-sd recovery card, so things are looking promising. Here's his thread:

http://www.androidtablets.net/forum...3-7035-7065-7060-so-repair-tablet-sdcard.html

 

[tpaine]

Vampirefo's method of recovery and running the operating system:

http://www.androidtablets.net/forum...-7035-7065-7060-so-repair-tablet-sd-card.html

is continuing to progress. Its looking likely his work will produce a universal method for recovery for all Gen 4 devices. The best part is, its all done thru a micro sdcard.


That method does not use the AMlogic flash tools and the method of connecting to a desktop computer configured with those tools.

It still seems there may be some utility in persuing this method. Below is a photo of the 8065 system board:




This shows the AML8726-mx. To the right is the Micron chip that is the location of the reset pins for deep brick reset. The 4 ram chips sit near the bottom of the board. Notice the 8060 marking on the board.

Please post any comments ideas you may have.