8,3 MacBook Pro 2011, running Ubuntu 11.10 amd64.
Here's the situation. Screen backlight and a few other things only work if booting in EFI, so I need to boot Ubuntu in EFI to get things working.
If I hold down Alt while booting and start Linux that way, then I boot into EFI just fine to my existing GRUB2 setup with screen brightness working.
I'd like to make this a bit more "automatic." I'm currently using rEFIt to allow me to boot into the various operating systems I've got on the machine. Unfortunately, rEFIt doesn't boot Linux in EFI mode, it uses a legacy mode, I believe, which seems to be equivalent to BIOS.
Thus, I installed a GRUB2 EFI module to rEFIt and I can now see that in my boot menu just fine. The problem is that I'm having boot problems. With the following GRUB command, I can see the kernel boot, but it hangs at
*ERROR* failed to get supported _DSM functions
and never actually completes. Here's my GRUB configuration file:
set debug=fg
insmod efi_uga
insmod font
if loadfont ${prefix}/unicode.pf2
then
insmod gfxterm
set gfxmode=auto
set fgxpayload=keep
terminal_output gfxterm
fi
menuentry "Linux (BIOS)" {
search --file --no-floppy --set=root /vmlinuz
loadbios /boot/vbios.bin /boot/int10.bin
linux /vmlinuz root=/dev/sda4 video=efifb
initrd /initrd.img
}
I basically have two questions.
Is there a way to enable EFI booting to Linux in rEFIt? If that were possible, I could avoid having to mess with GRUB altogether.
What am I doing wrong with GRUB? If I can't get rEFIt to play nice, how should I be booting my kernel in the EFI GRUB configuration file? I tried using the one on my system at
/boot/grub/grub.cfg
, but that didn't work either.
Why can I use Apple's "alt" loader to boot into Linux with EFI support, while I can't use rEFIt to boot into Linux with EFI support?
grub.cfg
which just loads the kernel normally (noloadbios
orvideo=efifb
entries).