.TH HXFS 4
.SH NAME
hxfs  \- hexamite active badges file system
.SH SYNOPSIS
.B hxfs
[
.B -A
]
[
.B -d
]
[
.B -s
.I srv
]
[
.B -m
.I mnt
]
[
.B -n
.I addr
]
[
.B -c
.I config
]
[
.B -V
.I volspec
]
.I iofile
.SH DESCRIPTION
Hexamite provides active badges that can be used to provide location
for users and devices. There are ultrasound microphones intalled in the
space that receive sound beacons from the active badges carried by users.
The only button on each badge adjusts the interval between beacons. It cycles
between a power-off state and different intervals. The led on the badge blinks
on each beacon.
.PP
.I Hxfs
services a file system that includes a file per badge. Each file contains the
current location (or locations) for the badge. There can be more than one
active location if several receivers are in range with the badge. Only the
three most recent locations are kept, sorted from newest to oldest.
.PP
Names for badges and locations are configured in
.BR /sys/lib/hxconf ,
or
.I config
when supplied. This file contains a series of
.B id=name
expressions, which map the
hexamite identifier
.B id
(printed on the badge)
to
.BR name .
.PP
Note that this driver is not intended to provide location information for
programs,
.BR /who ,
.BR /where ,
and
.B /what
should be used instead for that purpose. Other processes can use
.I hxfs
to update such directories according to heuristics acceptable for the users
involved.
.PP
Hexamite receivers are networked using telephone cable and
gatewayed through a serial port to the rest of the system. The
.I iofile
parameter is the file used
to obtain raw sensor data, usually a serial port.
.PP
Other options determine debug and how to export the file system and announce the
volume, like said in
.IR planb (4).
.SH SOURCE
.B /sys/src/cmd/hxfs.c
.SH FILES
.B /sys/lib/hxconf