Having used openwrt for a number of years I was pleased to find that I could install LEDE on my homehub5.
Following the various guides online, I managed to load the asc file over serial, upload the install image via tftp and run the prepare script.
At some point during the process I have done something wrong and when trying to run sysupgrade, I get "Nand upgrade failed". A bit of googling suggests that I need to reflash the BT firmware from the back up I made and start again. However, the USB device I used that was always a bit flakey has died and I have lost my backup.
Is there anything I can do or is the router bricked?
Its a spare one so nothing really lost but I would like to get it right before running the risk of bricking my other router.
Have you still got the serial console session open to see exactly what went on before you hit the problem?
If nobody suggests a better way forward, you could try taking a backup from your working HH5a ... and restore it onto the bricked one. The downside is that you'd have the calibration data from one router on the other one, and possibly duplicate MAC addresses too.
fwiw, core2lee has shared a nanddump from a Plusnet Hub One. You can find the link in this post:
Link deleted
I've tested restoring this nanddump to a HomeHub5 and it does work. Obviously, the admin password and wireless security passphrase are unknown, but this shouldn't be an issue if all you want to do is to use it reinstall LEDE from scratch, and avoid the potential issue of duplicate MAC addresses.
Installing LEDE does NOT overwrite the calibration data partition stored on the hub.
Imho, I think the settings specific for fine-tuning (calibrating) the wifi performance is likely to be the same for all HH5a coming off the production line, and are not end-user adjustable. As it is a mass-produced item made to the lowest possible cost for BT, I can't envisage a factory production line using equipment to individually tune the wifi of each hub as it would be time-consuming and costly. If I'm wrong, I'm sure someone more knowledgeable will correct me.
However, it is possible these performance parameters have been tweaked over the years given the first BT Home Hubs appeared more than 4 years ago.
The only other thing that will be different between each hub, is the MAC address data. If you had a backup of the caldata partition before restoring Plusnet nanddump to it, it may be possible to restore it. It's not something I've tested.
For QCA/ Atheros devices, the calibration data (ART) is typically unique to each device (or at least rather small production batches) and is never touched by firmware upgrades. It contains temperature curves for the used components, which do differ between devices.
Longshot I know as I see this was posted a while ago. I'm REALLY REALLY buggered as I'm in the same position as jonnyboy. Don't suppose you still have that backup mate do you ?
I'm in EXACTLY the same position as you cor2lees backup link is now dead
cor2lees backup link is now dead