Why is it necessary to install EFI/rEFInd/UEFI/... on a SD Card since the Macbook Pro seems to already have it?
- by user170794
Dear askubuntu members,
I own a Macbook Pro (late 2009) and when I boot the laptop and hold the alt key meanwhile, there is a EFI screen, so EFI is installed on... the firmware?
I had a few troubles with my hard disk, so I had to change it, but I haven't installed OS X, I have only installed Ubuntu and still the EFI screen is there which is surely a good thing.
As the new hard disk is making troubles again, I am using Puppy Linux, booting from a CD each time, which is unconfortable.
So I am trying to have Ubuntu installed on a SD Card. After having spent many months on the internet grabing informations anywhere I can and trying several things, I applied this method:
http://www.weihermueller.de/mac/
I succeeded in making one SD Card recognizable by the EFI of my laptop (holding alt key @ boot), but nothing installed on it yet as I fear to lose the recognizable-by-EFI part. I haven't succeded in producing the same result on another SD Card.
I have a bootable USB key of Ubuntu (yipee) which works like a live CD, made with the help of Universal Linux UDF Creator, found there:
http://www.pendrivelinux.com/universal-usb-installer-easy-as-1-2-3/
on which I have put Ubuntu 13.04 64bit, retrieved from the official deposits.
Eventhough I have to add the "nouveau.noaccel=1" option to the grub command line launching Linux, it works (yipee again) properly as a live cd.
When installing Ubuntu I come across the "where do I wanna put Ubuntu" window, I partition another SD Card in:
the EFI part (40MB)
the Linux part (15GB< <16GB)
The installation works fine and finishes with no problem.
But at the reboot, the SD Card where Linux is installed is not recognized by the EFI, the icons are :
the CD (Puppy Linux),
the USB stick (from Linux UDF Creator),
the hard drive (the formerly-working Ubuntu 12)
but no fourth icon of the SD Card whatsoever.
As the title of this thread suggests, I am wondering:
why there is a need for EFI to be installed on the SD Card since EFI seems to be on my laptop anyway?
why EFI has to be on a different partition than the Linux's one? How do both parts communicate?
why the EFI part on the SD Card made with the help of the live-USB key isn't recognized?
on the EFI partition, there is a folder named "EFI" which contains another folder named "ubuntu" which contains a file named "grubx64.efi", why is there a thing called grub? Is it the Linux's grub where one can chose either to boot, to boot in safe mode, etc.?
Thank you for your patience,
looking forward for any kind of answer,
Julien
