Debricking (another) Linksys EA8300

Installing and Using OpenWrt
1

Another tale of woe about debricking a EA8300. This is my first time installing and use OpenWRT, so generally excited to give it a whirl.

All operations are done via direct ethernet connection to the device with the device not connected to the internet and my host PC being disconnected from wifi.

Following the instructions on the device page , I successfully flashed the device, loaded up LuCI, and confirmed operation, browsed around a bit. I then moved on to the section about upgrading, performed the kernsize as written, and typed 'reboot', and the device does not come back online. The on start, the device flashes each port in sequence, flashs the Linksys logo twice, then goes dark. It does not provide an address to my machine, so I have to assume its not booting.

I've performed the Recovery (Automatic) but have not observed any change in boot behavior after several attempts and no IP is being assigned so still assuming it's bricked.

Anything else I can try or am I out of luck?

2

serial port?
it's described on the wiki page ...

3

By any change did you type = in the kernel size change command? I have read several cases doing so here in the forum.

If so the device hangs early in the boot process, whatever partition it is trying to boot. You must connect via serial, interrup boot process, restore the kernsize value within U-Boot console.

EDIT : once the serial link is done, you should read something like this
Hit any key to stop autoboot: 0

Press any key to enter U-Boot console. Type

setenv kernsize 500000
boot

Your device should now boot. As you can see it's not such a big deal. Also consider that the kernel size change is to be done only once in the lifetime of the device. You would not worry about this anymore.You can proceed to upgrade to 23.05.4. DO NOT keep settings while upgrading (DSA).

1 Like
4

Yes, I see that, but from what the device pages implies, that's potentially a couple of hours of investment (not sure what it entails, but I'm imagining I need to solder some connectors and use my raspi). My experience doing work over serial is pretty limited (and often unsuccessful), so I need to figure out all of that before I can even start on the instructions on the page.

So figured I'd stop here and see if maybe there's something obvious I'm missing first.

I mean, it doesn't say to do that in the command, and it explicitly says DON'T do that right under it. So no, I don't believe so

But unless someone comes along and has a "oh, this totally happened to me, here's how I fixed it" story, it sounds like I need to get the thing talking to something over serial, so I guess my next stop will be watching some u-boot videos and cracking the thing open as a side project with managed expectation

5

Alright, happy ending.

So I broke out my raspi and pinned the following:

Raspi       <-> router
TXD(pin 8)  <-> RXD (pin 3)
RXD(pin 10) <-> TXD (pin 2)
GND(pin 6)  <-> GND (pin 5)

This was a bit of a pain because the serial "pins" on the side of the board were actually just pads, so keeping the connections was a bit of a task. I also didn't have any experience running a serial terminal like this before, but after some consultation with Gemini and giving screen and minicom a whirl, I found that ttyS0 would output things to screen.

I spent an hour or so playing with different comments, trying to boot either partition, but both were failing which led me to believe I'd somehow destroyed both firmwares (!?). After getting nowhere, I went back to comparing the printenv I was seeing on the device, and the sample on the device page.

That's when the variable that started the whole thing grabbed my eye...

kernsize=50000

... wait a minute ... :: looks at the device page :::

kernsize=500000

Oh... damn.

With a setenv and a saveenv, bootpart2 was spinning and moments later I was looking at LuCI.

1 Like
6

Hence just a typo error in the very precise place you shouldn't make it :wink:
Glad you'd have been able to recover.
In case of trouble, have a look to the MR8300 page (yes MR, not EA). Its page is up to date.

I have read threads here where users typed =, while they MUST NOT. So I assumed you made the same mistake.

7

This topic was automatically closed 10 days after the last reply. New replies are no longer allowed.