Comment 118 for bug 1355698

I've managed to successfully install elementary with UEFI mode turned on with the UEFI 7 ISO above after messing around with it a little, having previously being unable using DD alone. After using DD to copy over the Linux Mint ISO, and then the elementary ISO, I noticed that - at least under gparted's interpretation - the USB stick produced by the elementary ISO didn't have any real/recognised partitioning ( although it worked fine to boot under BIOS compatibility mode), whereas the Linux Mint stick had two partitions, one containing the boot files, and one containing the rest of the system.

With that in mind, I completely zeroed out the USB stick I was using, and using gparted created a GPT partition table and filled up all the remaining space with a single fat32 partition. This is important from what I'm aware of because UEFI looks for the first fat32 partition it can find to find the boot files, so if the partition wasn't fat32 then it wouldn't be bootable at all, it's not essential for there to be a seperate boot partition either so having just one main partition simplifies things. Once a GPT partition table with one partition on it in with a fat32 filesystem has been created, just copy and paste the files from the elementary ISO over to the USB stick and it will work completely fine for the purposes of UEFI. Obviously copying and pasting the files could be done by any program capable of extracting the ISO, local loopback, etc.

After that's been done, I was successfully able to install the elementary uefi 7 ISO above in uefi mode on the computer, and it works perfectly. It won't solve any incompatibilities with Ubuntu/Derivatives mentioned above, but does boot and otherwise work exactly as expected.

I'm not exactly sure how the ISO image is generated in the first place, one potential trick to get more testing on this would be to create the usb stick as I described, use DD to create an image of the USB, and then ship that alongside the main ISO for this specific purpose of getting uefi capable computers to work, but creates unnecessary confusion and isn't ideal when shipping the stable ISO.