[seaniko7]

Upgrade procedure is following:
- User holds button whilst booting reader
- Bootloader (probably) checks if button is pressed
- Second kernel is unpacked and init process of initramfs executes update script
- Update script has embedded password (ArtaTech / Different Vendor) which is used for unpacking
- If password matches, update proceeds, otherwise Boox restarts

Updates are essentially whole rootfs plus kernel, which is flashed upon update as well.

So basically, yes; copying of firmware from other device would be sufficient, but here's the trick: you cannot do this on running system. To do that you will either need to flash memory using 'raw' access (using flasher in download mode) or use 'faked' updater ( with changed password ).

If you're interested, search for "Mixed FW" for M92, which combines Booxtor FW with ArtaTech FW. Note that I used ArtaTech encryption for Mixed FW due to legal implications, thus it works only for ArtaTech devices.

I guess, Booxtor could get in touch with ArtaTech guys and ask if they are ok with extracting their changes (obviously w/o IVONA TTS, which requires commercial licence). If yes, then I can handle combining Mixed FW for different vendors.