I admit it: I’m a little obsessed with bootable flash drives. Especially multi-boot flash drives. It’s replaced my obsession with multi-boot PCs. It’s an interesting challenge, and the end result can be useful. They’re great for forensics, data recovery and operating system repair, and these days with the shift to ultrabooks and tablets, they may be the only way to install an operating system.
As I mentioned back here Bootable USB Flash Drive Tools there are tools that can help or fully automate making a bootable flash – but I prefer to roll my own. Please double-check anything I suggest below. I’ve given it my best shot, but can’t guarantee it’s all correct – or won’t b0rk your computer.
This article discusses hand-made bootable flash drives using grub2 as the bootloader that can be legacy-bootable, UEFI-bootable, multiboot, or all of the above on the same fob. Some side trips on chain loading and persistence tossed in for good measure.
Legacy bootability testing was done on a Lenovo T400, UEFI testing on a Lenovo Twist. (The Twist has some issues when booting Ubuntu. See page “Stuff that doesn’t work…” at the end of this article.) Flash drive creation, file copying, grub2 installation, etc. on whatever was handy. Ubuntu 14.04.1LTS 64-bit is the live CD ISO used, both in its entirety (as a “vanilla” live CD) and as a source for grub2. Grub2 documentation can be found here: GNU GRUB Manual 2.00
There are no doubt several ways to skin this cat, and countless articles – so please forgive one more. This is a first pass and a little disorganized. Corrections and additions welcomed. Let’s go prep the flash drive…