howto interact with HW-detection of installer

["Geronimo Ma. Hernandez" <geronimo013@gmx.com>]

Hello,

I read the wiki of DebianInstaller and DebianCustomCD, as well as "debian 
installer internals", but I stil didn't get rid of how to interface with 
HW-detection part of the installer.

I would like to have different package-lists installed, based on the detected 
hardware.

So how can I determine the result of hw-detection? Does the installer use 
environment  variables or the /proc filesystem, or ... ?

Or do I have to build my own udeb for the hw I like to detect? 
... and if I do that, how can I switch the packagelist for the base installer?

There's a lot of information out there, but the installer is quite complex ...

Any hint is appreciated.

kind regards
Geronimo