Add -u to usage message.
Make usage power off.
Print kernel command line at start up.
Update docs.
Include constants.h into all source files with a -include directive.
Update.
Skeleton for students to use.
Reorder.
#include <stdint.h>
backtrace utility
Update docs.
Update.
Merge 16550a.h into serial.c.
Invent tid_t data type and use it in many places where we current use
struct thread *.
Remove thread_name() argument.
Make thread_unblock() on a thread that isn't blocked an error.
Move pagedir stuff into userprog.
Move flags into their own header.
Update docs.
Add thread priority support.
Add threads tests.
Clarify strtok_r() description.
Bug fixes.
Only destroy pages up to PHYS_BASE.
Update docs.