Looking for help with BQ Cervantes 4 stock flash

[Piecho]

Hello,
I just get second hand e-book reader with a good screen. I was very happy discovering, that there is possibility to use open source firmware on it.

There is a good news - it is still possible to flash it with KOReader and all the files are here. The bad, the documentation here is not clear for a nooby user.

Devs firmware guide
KOReader install instruction

I do have issues with the first instruction I posted.
1) How do you connect? You remove the cover, find the pads and what next? Is there any standard I should follow while connecting to Arduino? This is easy place to burn something in my experience.
2) The firmware for the Arduino or any other interface that should be used
3) As I understood you start the device and then send a signal ESC? What does it mean?
4) Then console in the device should appear and you input 'init=/bin/bash', then boot. By pressing power button again or other kind of signal?
5) etc

The more I read, the more I lost trust in my electronic and bash skills. The second guide is clear and files are still available in the webarchive. I will backup them and post here.

I believe that leaving this info for any other users still running stock may be good for all, as open source software should be spread. Especially when the producer does not support the device or the registration anymore.

For mods - mother thread is closed, I do not see a way to contact with author in PM either.

[pazos]

Originally Posted by Piecho

There is a good news - it is still possible to flash it with KOReader and all the files are here.

That's not what it is documented on the official wiki: https://github.com/koreader/koreader...-on-BQ-devices

Originally Posted by Piecho

The bad, the documentation here is not clear for a nooby user.

Even for an user that's familiar with the software involved and the materials required doing a hardware jailbreak might be cumbersome. It isn't the easiest device to open.

Originally Posted by Piecho

1) How do you connect? You remove the cover, find the pads and what next?

You need a USB to serial adaptor, using TTL @ 3.3v. Look at FTDI or Prolific chips. Please do your own research. There are thousands of resources online.

Originally Posted by Piecho

2) The firmware for the Arduino or any other interface that should be used
Is there any standard I should follow while connecting to Arduino? This is easy place to burn something in my experience.

On Linux and Mac the USB ttl should work out of the box. On Windows I'm not sure but certainly, if there's drivers required, it will be easily available somewhere.

You need to hook 3 wires. Tx, Rx and GND. Again, google is your friend. There's a lot of knowledge available online. If you don't get the pinout you'll also need a multimeter.

Originally Posted by Piecho

3) As I understood you start the device and then send a signal ESC? What does it mean?

You use a software like screen, minicom or putty to use the USB serial adaptor you bought. When you power the e-ink device you'll see debug messages on the program you're using.

Since the connection is bidirectional you are also able to "send" keystrokes. That means, pressing ESC while the bootloader is launching. Like entering in the BIOS on a regular computer.

Originally Posted by Piecho

4) Then console in the device should appear and you input 'init=/bin/bash', then boot. By pressing power button again or other kind of signal?

The bootloader launches the linux kernel and passes some arguments to it. The bootloader is u-boot and the arguments can be queried and modified from the u-boot prompt while you're at it. You need to modify the entire cmdline so it looks the original, but with that 'init=/bin/bash', to bypass the "normal" booting stage and get yourself a passwordless shell.

Originally Posted by Piecho

The more I read, the more I lost trust in my electronic and bash skills. The second guide is clear and files are still available in the webarchive. I will backup them and post here.

I have a backup for the Cervantes 2013, 3 and 4. That's not a problem.

The kind of questions you asked tell me you'll need to do some research before attempting to do the job. It shouldn't be too hard but it could be time consuming.

The more sensitive part is to open the device without broken it. If you have an electronics shop available there I would go and ask how much money its required for them to open the device, figure out the pinout and solder a header.

Originally Posted by Piecho

I believe that leaving this info for any other users still running stock may be good for all, as open source software should be spread. Especially when the producer does not support the device or the registration anymore.

I agree 100%. Unfortunately even with a 100% documented step-by-step guide it would be something unfeasible for some users. Still better than we have now.