Syslinux - Jun 2015 - Testing for ISO boot in init-premount

Hi

I have a scenario where I need to test for whether I have booted via a syslinux
ISO image in init-premount as opposed to (say) PXE boot. Is there any variable
that I can test for this?

thanks

vk

On Mon, Jun 22, 2015 at 7:30 PM, Varugis Kurien via Syslinux
<syslinux at zytor.com> wrote:
> Hi
>
> I have a scenario where I need to test for whether I have booted via a
syslinux ISO image in init-premount as opposed to (say) PXE boot. Is there any
variable that I can test for this?
As in you did "memdisk somecd.iso" to execute an ISO with ISOLINUX but
you want to know from within ISOLINUX if it was loaded from SYSLINUX
on a disk or PXELINUX via the network?

-- 
-Gene

Varugis Kurien via Syslinux <syslinux at zytor.com> writes:
> I have a scenario where I need to test for whether I have booted via a
> syslinux ISO image in init-premount as opposed to (say) PXE boot. Is
> there any variable that I can test for this?
I don't think you can do this without bootloader support.  And if you
can configure your boot loaders, then you can freely vary your kernel
command line or initrd contents, so this question does not arise...
So I'm not sure what you're after.  Maybe check out the IPAPPEND (or
SYSAPPEND) directive.
-- 
Regards,
Feri.

> Varugis Kurien via Syslinux <syslinux at zytor.com> writes:
> 
> > I have a scenario where I need to test for whether I have booted via a
> > syslinux ISO image in init-premount as opposed to (say) PXE boot. Is
> > there any variable that I can test for this?
> 
> I don't think you can do this without bootloader support.  And if you
> can configure your boot loaders, then you can freely vary your kernel
> command line or initrd contents, so this question does not arise...
> So I'm not sure what you're after.  Maybe check out the IPAPPEND
(or
> SYSAPPEND) directive.
> -- 
> Regards,
> Feri.
 
If the evaluation (before launching the kernel / OS / ISO image / 
whatever) consists on whether you are using either:
_ MEMDISK, vs.
_ non-MEMDISK

then there is ifmemdsk.c32. It might - or might not - be useful for 
your needs.
>From the perspective of the user, there is a "family" of c32
modules
acting as "conditionals":

_ ifmemdsk.c32
_ ifplop.c32
_ ifcpu(64).c32
_ whichsys.c32

with special attention to whichsys.c32.

The SYSAPPEND directive might be of some use to differentiate network 
booting from non-network booting, at least indirectly, because certain 
values should result in zero / null when not using network booting. 
Yet, I am not sure how such evaluation would be in use; either the 
appended boot options are relevant for network booting, or they are not 
(so, you would need to know the difference before actually booting the 
"whatever you are trying to boot").

Instead of asking whether there is something that would match the way / 
method you think your goal should be achieved, perhaps you might want 
to write what your actual goal is.

Regards,
Ady.
 
> _______________________________________________
> Syslinux mailing list
> Submissions to Syslinux at zytor.com
> Unsubscribe or set options at:
> http://www.zytor.com/mailman/listinfo/syslinux
>