I wrote back:
This removal of sigma0 need, happens at the L4::N1 implementation or is it a very recent l4:Pistachio improvemnet?
Now I'm a little more confused than last time. When you mean that you've removed the sigma0 need, you mean that it is not a provileged thread anymore?, giving freedom of implementation for memory management, so there is no thread memory space asingment at kernel level, and that task is now performed at a user level, at same level of memory manager? which makes sense. If so, would it be better having memory manager implementations wich will do both deliver memory for threads(sigma0) and manage memory?, is your simple sigma0 implementation http://www.ertos.nicta.com.au/software/kenge/sigma0/devel/, a demo of it?.
Just as a reminder, I havent found any information about the l4::N1, I'll have to search some more.