[ubuntu] Problems with mac boot

First post time

So I new to linux, but I have used it in virtual machines and stuff like that and I finally wanted a dedicated computer. So I have an older 2008 macbook pro that has been collecting dust, so I decided to install linux on it. I installed ubuntu on a bootable disk and completely replaced mac OSX with ubuntu. I did this without realizing that mac is EFI based, not BIOS. Now ubuntu doesn't boot from the power on, but everything is partitioned correctly. I can access the files via using the bootable disk as a 'preview' for linux. Although it runs from the disk drive, it gives me full access to the internal drive and files.

So, is there anything I can do to have it boot correctly, or am I screwed? Keep in mind, I no longer have access to mac OSX. Also, after inserting the disk, it gives me BOTH options to using EFI boot (Linux install disk) or windows (blank).

Thanks guys!

Edit: Quick update, I was about to make an EFI boot partition, and it shows in the bootable options, but whenever it tries to boot, it freezes the computer.