.TH APM 8
.SH NAME
apm \- Advanced Power Management 1.2 BIOS interface
.SH SYNOPSIS
.I (in plan9.ini)
.B apm0=
.PP
bind -a '#P' /dev
.PP
.B aux/apm
[
.B -d
.I device
]
[
.B -m
.I mountpoint
]
[
.B -s
.I service
]
.SH DESCRIPTION
.I Aux/apm
presents at
.I mountpoint
(default
.BR /mnt/apm )
an interface to the APM 1.2 BIOS 
(see
.IR apm (3))
.I device
(the default is to try
.BR /dev/apm ,
followed by
.BR #P/apm ).
If a
.I service
is specified, the interface will be
posted at
.BI /srv/ service 
as well.
.PP
The directory contains the following files.
.TP
.B battery
Contains one line for each battery in the system.
Each line lists three fields: the status (a string, one of
.BR unknown ,
.BR high ,
.BR low ,
.BR critical ,
or
.BR charging ),
the percent charge remaining, and
an estimate of the amount of time left in seconds.
If either or both of the last two are unknown,
the corresponding field will be zero.
.TP
.B ctl
The
.B ctl
file is used to set power management modes for
various parts of the system.
Control messages are of the form
.RI `` device " " verb ,''
where 
.I device
is one of
.BR system ,
.BR display ,
.BR storage ,
.BR lpt ,
.BR eia ,
.BR network ,
and
.BR pcmcia ,
and 
.I verb is one of
.BR enable ,
.BR disable ,
.BR standby ,
and 
.BR on .
.B Enable
and
.B disable
control whether power management is active
for the device, while
.B standby
puts the device into standby mode
and
.B on
brings it back to full power.
.TP
.B event
Reads from this file will block until an APM event
has occurred.
A large enough read is guaranteed to return
an integral number of textual event descriptions, one per line.
.SH SOURCE
.B /sys/src/cmd/aux/apm.c
.br
.B /acme/bin/Battery
.SH BUGS
The verbs
.B suspend
and
.B off
should be supported but doing so requires
nontrivial help from the kernel.