- Got rid of dummy proc[0]. Now proc[0] is init.
- Added initcode.S to exec /init, so that /init is
just a regular binary.
- Moved exec out of sysfile to exec.c
- Moved code dealing with fs guts (like struct inode)
from sysfile.c to fs.c. Code dealing with system call
arguments stays in sysfile.c
- Refactored directory routines in fs.c; should be simpler.
- Changed iget to return *unlocked* inode structure.
This solves the lookup-then-use race in namei
without introducing deadlocks.
It also enabled getting rid of the dummy proc[0].
Also remove all calls to memcpy in favor of
memmove, which has defined semantics when
the ranges overlap. The fact that memcpy was
working in console.c to scroll the screen is not
guaranteed by all implementations.
