Bug#693891: Fails to boot in UEFI mode on Dell PowerEdge R520

["Thomas Schmitt" <scdbackup@gmx.net>]

Hi,

> We'll just have to see if we get any more feedback.

Please keep me informed about any problems which are suspicious
to come from the early boot stages when the firmware has to find
its first piece of software on the medium.
(There are potential problems with partition tables at later
 stages, but i would assume that their cause would already 
 sabotage the early steps.)


> xorriso 1.2.6 now. So all of our images should get the latest and
> greatest features (and bugs :-))...

As far as new bugs are concerned, the known ones all do not affect
single session or bootability. (My new GUI demo lured me into some
command sequences which i never performed before. This yielded two
interesting new bugs. One week after release, of course.)

I did not program much in the bootability stuff during the
last half year. So few regressions towards 1.2.4 are to fear.
The Apple features (APM, HFS+) which where introduced with 1.2.4
are still my biggest concern. I had sparse test feedback from Vladimir
Serbinenko (who provided knowledge, code, and use case) but since
then it has become quite silent about that topic.


I still riddle about your -as mkisofs options. testr5.iso seems to follow
the mjg/ISOLINUX path to include a prepared HFS+ filesystem image into
the ISO image.  (-as mkisofs ... -isohybrid-apm-hfsplus ...)
But there are deviations from what i would expect:
The only APM payload partition starts at block 120236 and bears texts
"mkdosfs" and "FAT12". (The fact that its APM partition entry says
as type "Apple_HFS" is part of the mjg stunt).
 
When looking up the file in the ISO image
  $ xorriso -indev debian-wheezy-amd64-efi-test5.iso \
             -find / -lba_range 120236 1 -exec report_lba --
i get
  Report layout: xt , Startlba ,   Blocks , Filesize , ISO image path
  File data lba:  0 ,   120236 ,      224 ,   458752 , '/boot/grub/efi.img'

According to what i learned from mjg and Vladimir Serbinenko, the
consumers of APM will not be interested in the FAT image. The APM
of mjg's layout marks the FAT image only for informational purposes.
On 
  http://mjg59.dreamwidth.org/11285.html
he states
  "[...] not all Macs understand EFI El Torito, so won't EFI boot a CD
   unless there's an Apple partition map. Why have an HFS+ partition
   at all? Because the same Macs won't boot off FAT."

So currently it seems you add APM in vain because you do not add the
HFS+ image which its consumers would want in the next step of booting.
(I can of course no know whether my description in
  http://bazaar.launchpad.net/~libburnia-team/libisofs/scdbackup/view/head:/doc/boot_sectors.txt
 is entirely correct. It is based on hearsay and own image inspection.)


Have a nice day :)

Thomas