The goal is to insert device drivers in between.

I'd like to move this code, along with all recipe contents, to blk/.
It's easier if "emul-related" code is gathered at the same place.

With all this recent movements, we had a bit of a fragmentation
issue.

Not worth the complexity and space.

XPACK is more efficient than stripfc was, we can pack more stuff in 8K.
We now have enough space to fit readln.

Big bootstrapping change which greatly reduces the role of the modern
operating system in the bootstrapping process.

The way is clear for complete stage1 bootstrapping on the RC2014
target!