I own a Macbook Pro thats original HDD has been replaced with a SSHD, and the optical drive removed and replaced with a second SSHD. I have OS X installed to the drive in the optical bay, and Windows installed to the main bay. I can boot between them using the Bootcamp stuff or by holding Option during boot, there are no problems.
I just installed Ubuntu 14.04 to some extra space on the Windows/main bay drive, with a single ext4 partition. (I plan on using a swap file instead of partition) However, I haven't been able to successfully set up any bootloaders to triple boot. Here's what I've tried:
1. OS X Startup Manager
This menu only lists OS X, Recovery and Windows systems to boot into. I think this is because Ubuntu is installed on an ext4 partition. Can Apple's built-in Startup Manager see ext4 partitions?
rEFIt didn't work at all with multiple-drive setups, as their website says.
This is where things start to get weird. When rEFInd first shows up, it displays nothing but OS X (and OS X Recovery) If I first go into OS X's Startup Manager, then into rEFInd, it shows up with all three of my operating systems and boots into them properly. (With Ubuntu, I accidentally installed GRUB so it goes through ANOTHER step, but that can be removed)
Should I install GRUB to OS X? Would that work? Any help would be much appreciated.