#564509 grub2: unable to chainload a disk-/cdrom-image

Package:
grub2
Source:
grub2
Description:
GRand Unified Bootloader, version 2 (dummy package)
Submitter:
Date:
2015-05-19 07:54:14 UTC
Severity:
normal
#564509#5
Date:
2010-01-09 21:05:17 UTC
From:
To:
Hi,

grub2 is currently unable to chainload a disk or cd-rom (.ico) image. I want to be able to boot the Balder boot disk FreeDOS distribution [1]. I place the image file balder10.img into my /boot ddirectory and try to boot it from grub using the following commands (and several variations of it):

loopback (fd0) /boot/balder10.img
chainloader (fd0) +1

I always get the "invalid signature" error message. If I leave out the "+1" from the chainloader command I get the "no file specified" error.

I know it is possible to mount cdrom images (e.g. linux distribution live cds) and directly specify the kernel and initrd files relative to the loopbacked device. But that's not what I want (and it certainly only works for complete linux distributions and no other OSs). I want to be able to boot the image *as if the disc was inserted in the drive*.

For the Balder FreeDOS boot disk I currently help myself by loading syslinux-common's memdisk image via the linux16 command and the balder10.img image via the initrd16 command. But I don't favour to use a feature of another bootloader (i.e. syslinux) to actually boot a disk image from grub2.

Cheers,
Fabian

PS: Many other users have reported similar problems, e.g. <http://michael-prokop.at/blog/2009/05/25/boot-an-iso-via-grub2/#comment-14147>

[1] http://www.finnix.org/Balder
#564509#10
Date:
2010-10-17 23:17:51 UTC
From:
To:
Supporting hooking a device hook for this is pretty annoying and it
works only with OSes that only use BIOS services (which are only DOS,
and some even less used OSes). For this purpose you should use memdisk
from syslinux package (works nicely with GRUB)
#564509#15
Date:
2010-10-18 06:29:50 UTC
From:
To:
reopen 564509
thanks

I did not ask for opinions if this feature could be considered
annoying or not, I asked for its implementation. If you would have
read my entire bug report you would have known that I requested this
feature (1) because I want to boot FreeDOS from a disk image and (2)
that I currently use memdisk from syslinux-common, but find this
annoying and believe GRUB2 should provide this feature on its own.

  - Fabian
#564509#22
Date:
2010-10-18 07:04:11 UTC
From:
To:
If you supply a patch which implements this without putting an undue
strain on GRUB architecture it can be accepted. Until then FreeDOS is
just zero priority.
#564509#27
Date:
2010-10-18 07:07:56 UTC
From:
To:
Am 18.10.2010 09:04, schrieb Vladimir 'φ-coder/phcoder' Serbinenko:

I'm fine with this. Just please don't close my feature requests
stating that the requested feature would be annoying and telling me
the obvious. ;)

  - Fabian