> Can I do something in the kernel command line > to mount it automatically, so I can get my root fileystem from there?
If the command line contains 'readparts= bootargs=local!/dev/sdXX/fossil' and the kernel is built with partfs and fossil in the bootdir section, this should work automatically (with no need for sdB0part=). However I've just tried this and it doesn't work for me either. I will investigate further...