I accidentally deleted my EFI partition on OS X. It is completely gone. I need to fix it ASAP, so I have a few questions about this... 1) What exactly does the EFI partition do?2) Is the EFI partition necessary?3) How do I restore/repair/remake it? I have a Macbook Pro (13-inch, mid 2010) 2.4 GHz running OS X Yosemite 10.10.2. PLEASE HELP...more