[syslinux] Question on Kernel boot options

[Nazo]

On 1/8/06, Murali Krishnan Ganapathy <gmurali at cs.uchicago.edu> wrote:
> Since you have a CD there should not be any immediate space issues. In
> my opinion the best solution will be to build only the absolutely
> essential things into the kernel and keep everything else as modules. At
> boot time, you can pass options to the boot command line to
> enable/disable certain modules. All the options passed at boot time not
> understood by the kernel is available in /proc/cmdline. So your init
> scripts can use them and to decide whether to load certain kernel modules.
>
> All your users need is to pass in the right boot time options. But even
> that can be simplified by creating a menu of commonly used combinations
> and let the expert users to try various combinations. This way you will
> need very few kernels (in the ideal world only one).
>
> - Murali
>
> Michael D. Setzer II wrote:
> > -----BEGIN PGP SIGNED MESSAGE-----
> > Hash: SHA1
> >
> > I have a project that uses syslinux to load the kernels from the CD to create
> > disk and/or partition images. The process works great, but as I have been
> > building newer kernel images with new disk and nic drivers, I have had users
> > run into problems.
> >
> > Example: one users machine would fail at hotplug detection, creating a
> > kernel with this feature off worked. Another user had a problem wth the
> > cs8900 nic, and a  few others. Not many since I had 9,000 downloads of the
> > program in November for the last release, but I don't know how many of
> > those were downloads to use it, and how many mght have had problems,
> > and just not contacted me.
> >
> > I was wondering is using the isolinux.cfg to setup kernal boot options to have
> > a limited number of kernels, but provide additional configurations. Each
> > kernel is about 5MB, so limiting number cuts down on the image file.
> >
> > I've tried this by adding the debugboot option, but didn't see much differece
> > in the boot process, perhaps a few additional message lines, but my
> > machines don't get an error.
> >
> > Thanks for any information.
>
> _______________________________________________
> SYSLINUX mailing list
> Submissions to SYSLINUX at zytor.com
> Unsubscribe or set options at:
> http://www.zytor.com/mailman/listinfo/syslinux
> Please do not send private replies to mailing list traffic.
>
>
Two projects that use this method you can take a look at to get an
idea how it's done would be Finnix (www.finnix.org) and System Rescue
CD (sysresccd.org)  Both are live cd distros designed to be used for
system diagnostics and repairs, and, as such, have to be designed to
work on a maximum number of system.  Each has a myriad of options you
can specify to enable/disable various features (such as an option to
disable the automatic hardware detection you mentioned one user having
a problem with.)  I personally recommend looking at Finnix first as
it's a lot less complicated and even I can understand a fair bit of
the init scripts used.  I manged to get a vague idea of System Rescue
CD's inner workings, but, in the end I felt overwhelmed and never
really managed to do much.  Also, Finnix is still alive while System
Rescue CD seems to be stagnant now, so, you can actually speak to the
author to ask for some help with this or that.

BTW, I second the idea of using a menu.  Only a few combinations are
going to be used for a majority of systems, so it shouldn't be too
hard to build a simple menu for it.  Plus, the user can always just
hit tab and add any needed options to whatever menu item works best
for them when the options common enough to warrant their own menu item
fail.