Disable ctrl-alt-b?

[Per Foreby]

This is not really an fai issue, but since it is closely associated with
fai, I thought I'd ask here.

In the fai guide, the technique of always booting from the network is
described. It sounds very nice to be able to use fai-chboot to select
normal boot or install, without even having to touch the client.
But in my environment (students!), you always have to think about security
in the sence of protecting the computers from our own users.

Even if I enable all possible security in the BIOS setup, it is still
possible to press ctrl-alt-b to change the MBA settings. I'm not sure if
this is a security problem, but at least the students will be able to
change the settings and leave the computer unbootable from the network.

Does anyone know if it is possible to prevent the users from changing the
MBA settings?

If not, my backup solution is to only allow booting from C:, and password
protect all lilo/grub alternativs but local boot. This requires physical
access to the computers if I want to reinstall, but is still much better
than the bios solution (halt, enter bios, change boot order, install from
network, halt, enter bios, change boot order again, boot from disk).

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 Per Foreby     http://www.efd.lth.se/perf/