So, to summarize, some suggestions for Fairphone if they want to help customers prevent bricking their phones:
- Bundle a Linux version of fastboot, as is done by both /e/OS and iodéOS
- Order the flashing commands in the flash_FP5_factory script so that the critical partitions (the ones which must be present so the bootloader still functions) are flashed right after each other, as is done by iodéOS
- Only flash one slot (A or B) at a time and only proceed to flash the second slot after a reboot
- Change the error message to warn the user of the danger that their phone might now be in an unbootable state and to retry with another computer whilst NOT turning the phone off
- Even better would be to not have to download anything manually at all, but instead have a website such as https://flash.android.com/ to restore Fairphone OS
Even more ideas on how unbricking could work, as Fairphone are clearly not able to release a signed firehose loader to the public for security/legal reasons:
- Motorola-style “Blank Flash” image that can only be used to load bootloader to RAM for next boot
- SD card image that can load the bootloader. This would require a correct boot path in low-level firmware.
- As an online service where one can have this restore performed over the Internet without having to send the device in – perhaps using WebUSB
- By distributing to the angels or official local repair partners under NDA where you can just bring your phone to reflash. This would at least save from shipping across Europe. Murena seems to have the firehose loader as well (according to this report)