Hi there, I'm new here.
I just tried to setup my first OpenWrt Access Point using a Sophos AP55.
I got my hands on 3 of them second hand and was confident I was gonna pull it off using this very detailed guide. First weird thing was, that all my console output was completely garbled, which I assume was due to a faulty console cable, but as I knew what the console was supposed to say, I could barely make out what happened on my screen.
Now to my surprise (and delight) these AP55s already had OpenWrt installed, however it was not reset to factory setting and thus I was left with no root password.
I tried resetting it using the failsafe mode, but that would only interrupt startup and then do nothing. (Also btw for some reason the console output stopped being garbled after it launched into OpenWrt). Now I decided that I would just reflash the firmware, naive as I was. So I set up the tftp server, which also made some issued, but I got it figured out and finally launched into the installation. Despite the outbut being garbled, my inputs seemed to be completely fine. Followed all the steps outlined in the guide, but, to my horror, I read "Bad magic number" instead of "Ok".
Now I have two questions:
Is this recoverable or can I trash this AP (I do have two more tries after all '-.-) and if, how?
What did I do wrong? I followed the guide to the letter. Was it because OpenWrt was already installed maybe?
Never continue under those circumstances.
You might have connected the serial console wrong (e.g. Vcc connected, e.g. loose contact) or your serial console might be operating at the wrong voltage, damaging your device in the process. Even if none of those were the case, you have no control over what's actually happening, so chances to damage/ brick the device are just too high (or would you do eye surgery with an ice pick and a shovel? o.k., you will need the later…).
Very unlikely, there is no getty/ password login on the serial console - if you saw that, you either saw the OEM firmware or some modified thing.
It's not at all clear what's the current situation of your device. If you can get to the bootloader prompt, fine (you might have shot your WLAN capabilities, but) continue with booting the initramfs image and investigate from there, so start all over with the configuration again.
If you can't get the bootloader prompt (ungarbled, with the correct and working usb2serial adapter), Sayonara.
Thanks for the reply.
So first thing is getting a new Serial cable, got it.
Not quite sure what you mean by this. What I meant is, I get the OS startup sequence and a login prompt, but the default root + empty password doesn't work.
I got a new cable and my console is working fine now.
The bricked router is starting U-Boot just fine, so I tried getting the firmware installed with tftpboot again. It did load the image and I followed the steps in the howto again, but got Bad magic number again.
Then I redownloaded the image and tried again. Suddenly, everything works fine. I think I either moved the wrong file to my tftp server directory or downloaded the wrong image in the first place.
Anyways, thanks a lot for your help, I hope I don't blow more things up from this point on.
Oh and one thing I forgot to mention, one of the two other AP55s I have is looking for a AP100 Image, despited clearly being an AP55 (no 3rd antenna, also labled as AP55 on the casing), so maybe someone tampered with the bootloader on this one?
Should I just take and AP55 image and name it like an AP100 image to trick it or should I try using the AP100 image? Or should I dump that one entirely, after all these are second hand and the weird bootloader makes me a bit nervous bc of that.