[syslinux] Booting firmware harddisk image with memdisk fails

[Miller, Shao]

Very un-simple answer: Most sincere apologies.  I wasn't using your
isobar nor your patch for geteltorito, it turned out that _my_ image
extractor was broken, so I figured that Nero had put something bad in
the .ISO.  My extracted image only partly worked in VMWare, with the
corruption I mentioned.  DDing from the .ISO allowed the image to be
complete.  Using your geteltorito patch, I can confirm that the only
difference is the empty space in the .ISO, like you said.  So again,
sorry.

In the meanwhile, do other DOSes work?  What about a DOS "superfloppy"
image with the files all copied over?  Do other MEMDISK images work?  If
so, can the unit boot a MEMDISK HDD image of the exact same size with a
different DOS on it?  If the last test fails, perhaps it's a size
limitation.  A disadvantage that we currently have is that we don't have
any drive mapping abilities.  Booting an ODD, the optical disc is the
backing store for the emulated HDD.  Booting with MEMDISK, RAM is the
backing store, and maybe something critical is unfortunately up there.
If you're using a USB stick, you could try GRUB4DOS' mapping
functionality to see if the image works when its backing store is the
USB disk.

For the PXE case, where we have no media (heh), I'd _really_ be
interested in whether or not the SAN-boot works.  Because the SAN-boot
would have a mapping, instead of memory, this could also give some
clues.  If you want to try the SAN-boot method on this unit, but don't
have an iSCSI service resource, I could provide assistance there for
your test.

:S

- Shao Miller

-----Original Message-----
From: syslinux-bounces at zytor.com [mailto:syslinux-bounces at zytor.com] On
Behalf Of Dag Wieers
Sent: Sunday, May 24, 2009 16:42
To: For discussion of Syslinux and tftp-hpa
Subject: Re: [syslinux] Booting firmware harddisk image with memdisk
fails

On Sun, 24 May 2009, Miller, Shao wrote:

> Very simple answer: The .ISO was created with Nero, and the HDD
"image"
> is actually just enough to boot, then the rest of the sectors are on
the
> rest of the .ISO.  Extracting just this truncated HDD "image" does not
> have everything in it.  Is has some of the files in the image's
> partition's root directory, but nothing in the Flash\ directory, plus
> some of the root files might be corrupted.  To _really_ extract this
HDD
> image, do:
>
> dd if=6duj 08uc.iso of=thinibm.fat skip=108
>
> (108 is the HDD image's starting sector, 27, times 4 times as many
> 512-byte sectors in a 2048-byte ODD sector.)

Shao,

I extracted the image as explained in this thread using isobar or 
geteltorito (both provide me with exactly the same image) _and_ the
image 
boots fine from Qemu so I don't think there is anything wrong with the 
image at all.

If I compare both images, yours contains a series of nulls (about
317440).

--
--   dag wieers,  dag at wieers.com,  http://dag.wieers.com/   --
[Any errors in spelling, tact or fact are transmission errors]

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