I'm dual-booting a late-2013 Macbook Pro with Ubuntu 14.04 x64 (vmlinuz-3.13.0-24-generic) and OSX 10.9.2 with Refind. This worked well after I installed Refind's ext4 driver.
I also have the hard-drive from my previous laptop on a USB external drive with copies of Windows and Ubuntu on separate partitions which I'd like to boot on the Mac. I can mount these partitions on OSX or Ubuntu, but as Refind didn't recognise the installations I used Gdisk to change the disk to GPT.
After that, Refind recognised the existence of the external Ubuntu and Windows installations, but doesn't give any information about the kernel and shows a penguin icon for Ubuntu. Trying to boot this leads to a pause then a blank screen with the message:
No bootable device - insert boot disk and press any key
I added a stanza in refind.conf referring to Ubuntu by UUID, and I added a refind_linux.conf to the Boot folder in the Ubuntu 13.04 x64 partition on the external drive, but this made no difference:
"Boot x64 13.04 with standard options" "ro root=31b998f7-0607-40f3-ba7f-67f297d79a2d quiet splash"
Can anyone suggest where I've gone wrong, or how to get it working?