Triple boot UEFI System Win 8.1/Kali 2016.1/ubuntu 15.10
 

I have Wins 8.1 and Kali rolling 2016.1 dual booting fine; will like to know how to get uBuntu 15.10 to show up as a selection from the Kali boot screen for a triple boot system.

I installed ubuntu without installing ubuntu grub2 bootloader.

Hi,

So, If I understand well, your grub and its configuration comes from your Kali side.

Ok, you have to boot into Kali and as root:

NOTE: you have to replace OUTPUTFILE by the file containing your configuration (e.g. /boot/grub/grub.cfg). Don't forget to make a backup of the file first.

Normally, grub must see the vmlinuz on the Ubuntu partition and add it to your grub menu.

All the best.

Since it is a UEFI system, you have several options. During POST, you can press one of the F keys to bring up the UEFI boot options screen. This will show all of your operating systems. The F key depends on the manufacturer. F8, F9, F2, etc., depending.

Another way is to set in /etc/defaults/grub and run as the previous poster said.

You could also edit /etc/grub.d/40_custom and add a chainloader stanza. But since you did not install Ubuntu bootloader, this might not work. You can also add a direct boot stanza to 40_custom which should work. But os-prober does this automatically. I have never used Kali, so I don't know if os-prober is installed by default.

Thanks guys, I was able to get the grub2 in Kali to boot the ubuntu partition. I loaded Boot-Repair ISO on a USB stick, and boot off of it. It updated the Kali grub2.

When I boot, Kali grub2 load, and allow me the option to choose the Ubuntu, Kali or Window 8.1 partition, which I really wanted, and not ubuntu grub2.

For days, I was face with the issue loading Ubuntu, when it reach with the grub install it will hang. So I decided to load Ubuntu without the grub and let Kali take control, but Kali was not seeing the Ubuntu partition.

I wish I had tried the options posted, to see how they works, as I am all about experiencing. If I reload I will sure try these options.

Thanks once again. I just love love linux and the supports here.