I've recently bought an usb3 flash drive where I've put a live kali linux distribution. When I try to boot my early 2015 mac book pro (with Yosemite) from this usb3 drive I have two options: windows or efi. If I select the efi option everything freeze and I need to hold down the power button to force a shutdown. If I select windows option instead everything works well. With an usb2 flash drive, instead, the efi option can load the live kali linux distribution.
Why this behavior? What the differences between windows and efi options?