Kernel configuration file in Debian/NSLU2

[Xan <DXpublica@telefonica.net>]

Hi,

I have a slug and I installed debian with the installer (following 
http://www.cyrius.com/debian/nslu2/install.html)

Now, I have the system working fine, but I want to make several things:

1) the one is securing kernel. Specifically, I want to install 
grsecurity patch to the kernel (or only pax patch)

My plan is to compile new kernel with the same configurations as the 
default kernel plus the grsecurity. By this way, because the default 
kernel is working, I "assure" that the new will work

But for that, I need to know what are the configuration file of the 
default kernel (2.6.18-4-ixp4xx)

Where can I get it?

2) Secondly, maybe I want to enable selinux that it's installed but not 
activated. For do that, I have to change and put "selinux=1" in kernel 
parameters (following the http://wiki.debian.org/SELinux), but in slug 
it's installed redboot and apex and I don't know how can I change it

3) Thirdly, I want to know how backup _all_ the contents in the slug and 
how can I restore it if the new kernel I compiled not works


In advance, I thank you all you efforts to answer me.
Xan.