RE: Cannot boot from dual bios/uefi boot CD

[John Frankish]

> > 
> > 2. modified grub.cfg with "set root=(cd0)" and (perhaps not required) "set 
> > prefix=($root)/EFI/BOOT/grub"
>
> This may fail if there are several CD present and grub is not booted from the 
> first one (in firmware scan order).
> On EFI you can set prefix to ()/path (grub-mkimage ... -p "()/boot/grub"); 
> "()" as disk designation means "set root to
> whatever device I was booted from" and path is taken from prefix then.

Sorry, but I'm not sure I figured that out correctly. Taking my example above, 
should I use:

set root=()
set prefix=($root)/EFI/BOOT/grub

> Also to notice that there is no access to ESP itself  after grub is booted 
> (i.e. content of efiboot.img in your case).
> Any path should refer to path on iso9660 part. In particular, grub.cfg - if 
> any - must be on ISO, not in ESP image.

That's what I did - perhaps confusingly, the path on both the iso and in 
efiboot.img was /EFI/BOOT

> Actually it was quite educational and useful exercise. Thank you!

And for me too :)