[syslinux] Boot fails in a VMware player VM - syslinux 6.03

Ady
Tue, 11 Nov 2014 01:55:51 -0000

>  > You are probably imitating / following some procedure used by
>  > Slackware to create EFI-compatible ISO images. The problem, as
>  > mentioned in a recent email this last week, is the particularities of
>  > the documents regarding, in this case, grub2 as EFI bootloader (as
>  > oppose to documents covering EFI bootloaders in general and clearly
>  > indicating the specifics about one particular bootloader).
>
> That's right, what I did imitates the procedure used by Slackware that
> uses grub2 as EFI bootloader.

But you have not considered the (requirements', features',...)
differences between grub2 and syslinux.efi.

>
>  > Currently, Syslinux is not capable of booting optical media in EFI
>  > mode. So your VM, when being set to use EFI and this ISO image as
>  > virtual boot media, will fail.
>
> I assumed that post-precessing the ISO image with "isohybrid -u"
(as I do
> when using grub2 as EFI bootloader would work the same when using syslinux
> as an EFI bootloder.
>
> So that was a wrong assumption... Maybe a warning about that in this
> wiki page:
> http://www.syslinux.org/wiki/index.php/Isohybrid
> wouldn't be useless, then...

No warning needed (it would be inappropriate). The problem is not in
the isohybrid command, neither related to it.

If syslinux.efi were capable of booting optical media in EFI mode,
then booting your EFI VM with some (correctly built) ISO image would
work. The isohybrid command is relevant for non-optical media, i.e.
booting your EFI VM with the virtual HDD and not with the ISO image
as virtual optical media.

>
>  > I don't know how exactly you are building your virtual HDD to
boot in
>  > EFI mode. In /EFI/BOOT/syslinux.cfg, you could:
>  > _ comment out the FONT directive;
>  > _ comment out the DISPLAY directive;
>  > _ comment out the TIMEOUT directive;
>  > _ keep using "PROMPT 1" and _no_ UI directive (as it is
already).
>  >
>  > If your HDD image and the VM are built adequately for booting in EFI
>  > mode, then commenting out these directives should at least give you a
>  > Syslinux "boot:" prompt when booting to the virtual HDD
image (in EFI
>  > mode). If such initial test is successful, then you could move on to
>  > additional testing steps. If it fails too (i.e. you don"t get to
the
>  > boot prompt), then some additional info would be needed.
>
> I'm using an hybrid ISO image. I tried to comment out those dierctives
> in /EFI/BOOT/syslinux.cfgto no avail: I still get the same error message
> at (failed) boot in vmplayer:
>         "The firmware encountered an unexpected exception"

Your isohybrid ISO image will fail, as the GPT EFI bootloader that
you built in your mksiofs command is inadequate.

>
>  > If you are really trying to boot your EFI VM with a (either real or
>  > virtual) USB drive (instead of using a virtual fixed HDD), then some
>  > additional considerations might be necessary.
>
> I tried that too with a real USB stick, but still get a black screen
> with a message (herd to read as it disappears quicly):
>    "Failed to read block: ox2"

Again, dd'ing your isohybrid image onto your (virtual or real) drive
will fail to boot in EFI mode. Your "syslinux.efi-based"
"/isolinux/efiboot.img" will not be capable of booting. This is one
of the steps that corresponds to grub2, not to whichever other EFI
bootloader you use (e.g. syslinux.efi).

>
> I'll give more information in my answer to Thomas.
>
> Thanks and best regards,
>
> Didier
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There is one additional consideration. You are building a x86_64
isohybrid image. Some virtualization software might not be capable of
running a 64-bits guest if the host doesn't have virtualization
available in its own firmware.

Regards,
Ady.