I should have mentined that I did quite lot of googling before deciding to post on linuxquestions.org
Search results were basically in one of the following categories:
- Microsoft sued tomtom over fat & linux
- No linux software available for tomtom
- tomtom is built on top of linux, here is how to hack it
the opentom.org is about hacking your tomtom, including hardware modifications. Even on opentom.org they state:
1. Make a full backup of the TomToms content
Do it with TomTom HOME, but also copy really everything from the TomTom internal memory to your harddisk.
So not really a solution there.
I have found pyTOMTOM
which can be used to update GPS quickfix data or to backup and restore the GPS unit. I need to experiment with that one. Perhaps it will be the solution for my needs.