Roadmap to Birds Memory Layout

----prot lo----
lddata
gsdata
gsbss
sheap
...
for(running procs)
{
  ...
  pheap
  gpdata
  gpbss
  args
  pstack
  ...
}
for(all procs)
  process descriptor (2W)
for(all procs)
  istack (32W)
----prot hi----
