Re: GRUB doesn't recognize partitions on El-Torito image during EFI boot from CD

[Andrey Borzenkov]

On Tue, Nov 12, 2013 at 11:50 AM, Jacek Konieczny <address@hidden> wrote:
>> Could you give example how your image is seen in EFI shell?
>
> What EFI shell command should I use for that?
>

Using "map" would be a good start. You may use "map -b" to paginate.
Could you dump it to a file (use e.g. USB stick for it) and attach?

Assuming that fs2: refers to writable partition

fs2:
map -v > map.out

>
>> It is not forbidden in any way; it is just that such CD will not be
>> directly bootable by EFI.
>
> The strange thing is – my previous 'prototype', with EFI shell and
> ELILO, was bootable. And GRUB loads too, it just cannot see the other
> files on the image.
>

Could you please describe step by step how you build your CD? Exact
command line(s) would be helpful.

>
> Would [grub] see the files on ESP when it was a proper EFI El-Torito image,
> as defined by the specs (unpartitioned, no emul)? If not, would it still
> be possible to chainload any other EFI application from this image?
>

Not without special arrangements. grub-mkrescue is using xorriso which
builds hybrid ISO image containing extra partition table(s) which
results in GRUB being able to access El-Torito boot image as normal
HDD partition.

>
> I wanted to be able to chain-load other EFI applications (like the EFI
> shell) from the GRUB, so I wanted files to be available via the EFI
> services – putting the files on the 'ESP' FAT file system made them
> available to any EFI application. I could not use the 'standard CD' this
> way, as EFI cannot read ISO9660 file system directly.
>

Makes sense. Hmm ... it sounds like extending grub-mkrescue to allow
adding arbitrary content to ESP will be the most easy solution in your
case.