Video #4: How I reflash the Librem 5


I made a video of how I reflash my Librem 5.
I hope this might help someone :slight_smile:


It would help many if it was in English.

Yes, that’s true, but you can activate subtitles, this can help :slight_smile:

1 Like

Why one has to pullout the battery before starting to write the image to the phone?

I don’t know exactly, but inserting the battery triggers the next step in the flash process. I cannot answer you whether this has a deeper meaning that there should be no battery in the uBoot flashing.

It’s just so you start from known valid state. The only thing that actually needs to be done to put the phone into flashing mode is to hold Vol+ while it boots (or reboots).

The problems start when, say, your phone gets into a locked up state where the SoC is on and needs full reset, but it appears off to the user - so you need to hold the power button for ~16 seconds to reset it. BUT… because of the way full reset it implemented in the battery charger controller, it doesn’t work when there’s USB plugged in, so you need to plug it out. HOWEVER… when you plug it back in when there’s not enough juice in the battery, you may trigger a condition on early batches where USB-C port becomes unoperational until another full reset. This combined with the fact that there’s no indication that the phone went into flashing mode and it still appears off to the user can lead to a lot of confusion and walking in the dark trying to make it work.

So… it’s just easier to recommend taking your battery off even if you don’t really have to do it :slight_smile:


Looking at the steps more generally, it could also be considered a security feature that it would be very difficult for a remote attacker to simulate the steps i.e. can only flash with local access. :wink:

In other words, even if your operating system is completely pwned, an attacker may not be able to escalate that attack to make it more persistent by changing the firmware - and conversely you have a guaranteed way to regain control of the operating system by reflashing.