[Tutorial] Recovering GRUB in HC2

[Vallefor 4]

Hello.

 

I wanted post it here: https://forum.fibaro.com/forum/129-other-solutions/ but i have no rights for it.

 

First of all I want to say that it is totally not recommended to do it. If you have similar problems - ask for support first!
DO IT ON YOUR OWN RISK! Probably this will end your warranty (but my already ended).

 

Two days ago a need to do some electric works and I shutdown my HC2 by pressing power button.

Then, when I finished - I switch it on leds start to blinking... but nothing hapened. I tried to boot to recovery but it did not boot also.

 

I unscrewed left panel of HC and attach monitor to see whtats hapening. And I sawed that it is immediatly reboot after selcecting a boot device. 

 

It was a GRUB problem. This tutorial is for linux users.

Btw, my HC2 version is  4.550.

 

1. You need:

>=1Gb flash drive

Keyboard

Monitor with VGA connector

Linux PC (you can prepare USB drive on Windows, but I do not know how, sorry)

 

2. Preparing flash drive

Download Debian 6 image:

https://cdimage.debian.org/mirror/cdimage/archive/6.0.10-live/amd64/usb-hdd/debian-live-6.0.10-amd64-rescue.img

And flash it to usb drive (this will erase all your data on flash drive):

dd if=debian-live-6.0.10-amd64-rescue.img of=/dev/sdc

/dev/sdc - is your USB Flash.

 

3. Boot with prepared flash drive

Power off HC2.

Insert USB Flash.

Remove fibaro recovery usb-drive.

Press F10 like crazy after power on.

Select your USB flash in menu.

 

4. Fixing grub

When GRUB of flash drive appering - select failsafe mode and press enter

After boot sequence will compleate you have about 5 minutes to fix your problem (after sometime something will reboot your HC2).

 

Determine system drive device:

ls -al /dev/disk/by-label

 

You will see something like: 

...
lrwxrwxrwx 1 root root  10 Nov  9 14:38 SystemFS -> ../../sdb2
...

So, sdb is your target drive.

 

Mount SystemFS with write permissions:

sudo mount /dev/disk/by-label/SystemFS /mnt -rw

Install GRUB to your target device.

sudo /usr/grub/grub-install --root-directory=/mnt /dev/sdb

Now you need to fix grub.cfg

vi /mnt/boot/grub/grub.cfg

grub.cfg should become like this:

set default="0"
set timeout="5"

menuentry "Buildroot" {
        set root=(hd0,msdos2)
        linux /boot/bzImage
        initrd /boot/initramfs
        boot
}

5. Reboot

Do not forget to remove your flash drive.

It shodl boot normaly now.