Syslinux - Jun 2011 - Chainload isohybrid image from extlinux

Hi,

I'm trying to boot Debian-Installer image from extlinux with chain.c32;
i.e.:

- I'm doing this from a loopback device (loop0) which later will be
dumped to an USB stick.
- GPT disklabel.
- Partition 15 (loop0p15) contains extlinux info, and partition 12
contains Debian multi-arch installer image *dumped*[1], and its
corresponding menu entry for extlinux is something like:

LABEL debian
MENU LABEL Debian-Installer
COM32 chain.c32
APPEND hd0 12

Using qemu to boot off /dev/loop0, after selecting this option from
extlinux's menu the message stored in isohybrid MBR is displayed:
"isolinux.bin missing or
corrupt", but booting from /dev/loop0p12 displays the Debian's splash
screen and works.

I have found no way to chainload this isohybrid image from extlinux. There is a
way to do that?

In the Syslinux Wiki about chain.c32 module, one can read the following text:
"chain.c32 is a COM32 module for Syslinux. It can chainload MBRs, 
partition boot sectors, Windows bootloaders (ntldr, setupldr.bin and 
bootmgr), MS-DOS and PC-DOS io.sys, Freedos kernel.sys, isolinux.bin 
(only from ISOLINUX) [...]", so the answer is no?

Thanks.

[1] cat debian-[...]-netinst.iso > /dev/loop0p12

On 06/11/2011 05:12 PM, Emilio Lazo Zaia wrote:
> Hi,
> 
> I'm trying to boot Debian-Installer image from extlinux with chain.c32;
> i.e.:
> 
> - I'm doing this from a loopback device (loop0) which later will be
> dumped to an USB stick.
> - GPT disklabel.
> - Partition 15 (loop0p15) contains extlinux info, and partition 12
> contains Debian multi-arch installer image *dumped*[1], and its
> corresponding menu entry for extlinux is something like:
> 
> LABEL debian
> MENU LABEL Debian-Installer
> COM32 chain.c32
> APPEND hd0 12
> 
> Using qemu to boot off /dev/loop0, after selecting this option from
extlinux's menu the message stored in isohybrid MBR is displayed:
"isolinux.bin missing or
> corrupt", but booting from /dev/loop0p12 displays the Debian's
splash screen and works.
> 
> I have found no way to chainload this isohybrid image from extlinux. There
is a way to do that?
> 
You have to use the version of isohybrid that supports being loaded off
a partition.

	-hpa