harvey/sys/doc/fs/p8

.SH
9P Protocol Drivers
.PP
The file server described so far
waits for 9P protocol messages to
appear in its input queue.
It processes each message and
sends the reply back to the originator.
There are groups of processes that
perform protocol I/O on some network or
device and the resulting messages
are sent to the file system queue.
.PP
There are two sets of processes
.CW ethi
and
.CW etho
that perform Ethernet input and output on two different networks.
These processes send Ethernet messages
to/from two more processes
.CW ilo
and
.CW ilt
that do the IL reliable datagram protocol
on top of IP packets.
.PP
The last process in Emelie,
.CW con ,
reads the console
and calls internal subroutines to
executes commands typed.
Since there is only one process,
only one command can be executing at a
time.
See
.I fs (8)
for a description of the
commands available at the console.