[syslinux] syslinux tool for Win2k and 'safeboot' option

[H. Peter Anvin]

Ole Hansen wrote:
> 
> 2.
> Is it possible to setup syslinux.cfg for some kind of safeboot, so for
> instance you could have  2 labels for kernel and if the system don't
> properly from the first, then boot from the other on next boot ?? This could
> be made with some kind of a flag in memory and a small utility to be called
> from linux to clear this flag, if boot succeded.
> We see this as a nice feature, if you want to install a new bootfile etc...,
> remotely via network.
> 
> Sorry if these subjects have been discussed before, but I haven't seen
> anything about it, when I looked in the FAQ-archive.
> 

This is all but impossible to do locally, simply because I don't believe
there is anywhere to store this flag.

I believe Microsoft has been pushing BIOS vendors into making some
location in the CMOS available for this purpose.

There *is* one way you could do it, but it would involve server-side
hacking (and thus is beyond the scope of pxelinux, but perhaps something
to consider for tftp-hpa):

When the client requests a configuration file, give it the standard
configuration file and change a setting on the server so that the next
request will give a different -- the "safeboot" configuration file.

Once Linux has booted, send a reply to the server letting it know that
the server should change back to the normal response.

This requires a TFTP server which can perform an action after a request,
in addition to delivering files.

	-hpa