Each of these functions assumes that the user address has already been
verified to be below @code{PHYS_BASE}. They also assume that you've
-modified @func{page_fault} so that a page fault in the kernel causes
-@code{eax} to be set to 0 and its former value copied into @code{eip}.
+modified @func{page_fault} so that a page fault in the kernel merely sets
+@code{eax} to 0 and copies its former value into @code{eip}.
@node Project 2 Suggested Order of Implementation
@section Suggested Order of Implementation
@deftypefn {System Call} int open (const char *@var{file})
Opens the file called @var{file}. Returns a nonnegative integer handle
called a ``file descriptor'' (fd), or -1 if the file could not be
-opened. All open files associated with a process should be closed
-when the process exits or is terminated.
+opened.
File descriptors numbered 0 and 1 are reserved for the console: fd 0
is standard input (@code{stdin}), fd 1 is standard output
@end deftypefn
@deftypefn {System Call} void close (int @var{fd})
-Closes file descriptor @var{fd}.
+Closes file descriptor @var{fd}.
+Exiting or terminating a process implicitly closes all its open file
+descriptors, as if by calling this function for each one.
Consider implementing this function in terms of @func{file_close}.
@end deftypefn