Bricked router?

[kcobain1992]

Hi,

As I was playing with my RT-AC56U, I was following this tutorial: http://forums.smallnetbuilder.com/showthread.php?t=15528 to run some stuff in Debian chroot at startup.
Unfortunately, at reboot, it seems that my router executes /jffs/scripts/services-start, but never gets out of it.
If I remember correctly, it was something like this:

ln -s /jffs/configs/profile.add /home/root/.profile
ln -s /jffs/configs/.vimrc /home/root/.vimrc
sleep 10
/usr/bin/debian-mount

The first two commands worked, but I think it didn't like the sleep command. FWIW, the "debian-mount" script looks like this:

mount -o bind /dev/ /opt/debian/dev/
mount -o bind /proc/ /opt/debian/proc/
mount -o bind /sys/ /opt/debian/sys/

Similar stuff was happening in the services-stop script:

/usr/bin/debian-umount

but I don't think it gets until there.
Well, as I said, now, after reboot, it never completely starts, the lights don't go on (only the power light), and I can't ssh into it. I tried unplugging the USB stick that was mounted as /opt, and rebooting again, but no succes that way either. I also reset the NVRAM (I think) by holding the reset button for 30 seconds. What can I do?

 

[kcobain1992]

Well, the actual question is:
What scripts are executed by the OS before /jffs/configs/services-start?
Which of these scripts source any other script mounted in /opt? I only know of /etc/profile that sources /opt/etc/profile if it exists.
What I have to do is create /opt/etc/profile (or whatever other script that starts before services-start) on the USB stick, and make it remove that ugly script before it gets executed.

 

[Hexabion]

I'm able to telnet into my router many times before services-start is initiated, so I don't think your services start is the problem here.

You could try a reset by turning off, holding in wps/radio button (and/or reset button) in 30 secs, then turning it on while still holding the reset/wps button, then keep pressing it for 30 seconds more, then let go, then let the router brreathe for a couple of minutes, then turn if on/off like normal again.

Eventually you can put a huge HDD into the USB-slot, which should make it try to scan the disk on bootup for errors like normal, in which it will give you time to telnet in before services-start is initiated.

I always make my startup scripts check for the presence of a "stop" file or dir on the external disk I have mounted on USB, making it exit the script immediatly e.g. if it finds the directory mnt/system/stop (i cant post the code here due to smallnetbuilder blocking it.

I use a neverneding services-start loop instead of crond, without any problems, containing a sleep 5 on each loop. I can still use my router like normal, and access everything, webgui, telnet etc. I dont see how a running or stuck services-start would brick or prevent your router from actually booting or running.

 

[kcobain1992]

Ok, how else can I diagnose what's wrong? I disabled telnet login, as it was unencrypted.

 

[Hexabion]

Ok, how else can I diagnose what's wrong? I disabled telnet login, as it was unencrypted.

Do you have entware installed? If so you can insert a command directly in /opt/etc/init.d/rc.unslung if you have rc.unslung started from another script in /jffs/scripts/ (e.g. post-mount etc.)

Then you could insert "rm /jffs/scripts/services-start" directly in rc.unslung since rc.unslung is a sh-script just like services-start is. rc.unslung is reachable on whatever external hdd you have connected aswell if you have entware installed, so connect it physically to your pc/windows, edit rc.unslung in notepad++ from there, save and reconnect hdd, and restart router.

If you don't have entware installed, then you need to go into recovery mode.

Check this: https://code.google.com/p/rt-n56u/issues/detail?id=54

And google: N56u recovery mode.

I'm 100% confident you'll get your router back. Hard-bricking a NXXu is very very seldom, those whom have managed to do so actually deserve a medal.

 

[kcobain1992]

Thanks.
After repeatedly holding the reset and WPS button pressed, it did boot eventually.