APMD(8)                 OpenBSD System Manager's Manual                APMD(8)

NAME
     apmd - Advanced Power Management daemon

SYNOPSIS
     apmd [-AaCdHLs] [-f devname] [-S sockname] [-t seconds]

DESCRIPTION
     apmd monitors the advanced power management device, apm(4), acting on
     signaled events and upon user requests as sent by the apm(8) program.

     For suspend and standby request events delivered by the BIOS, or via
     apm(8), apmd runs the appropriate configuration program (if one exists),
     syncs the buffer cache to disk and initiates the requested state.  When
     resuming after suspend or standby, apmd runs the appropriate configura-
     tion program (if one exists).

     When the power status changes (battery is connected or disconnected) apmd
     fetches the current status and reports it via syslog(3) with logging fa-
     cility LOG_DAEMON.

     The options are as follows:

     -A      Start apmd in automatic performance adjustment mode.  In this
             mode, when CPU idle time falls below 10%, or if the AC power is
             connected and the battery is more than 15% charged, apmd raises
             hw.setperf to 100.  Otherwise when CPU idle time is above 30% and
             the system is running on battery power, apmd lowers hw.setperf as
             much as possible to reduce power consumption.

     -a      BIOS-initiated suspend or standby requests are ignored if the
             system is connected to line current and not running from batter-
             ies (user requests are still honored).

     -C      Start apmd in cool running performance adjustment mode.  In this
             mode, when CPU idle time falls below 10%, apmd raises hw.setperf
             as much as necessary.  Otherwise when CPU idle time is above 30%,
             apmd lowers hw.setperf as much as possible to reduce heat, noise,
             and power consumption.

     -d      apmd enters debug mode, logging to facility LOG_LOCAL1, and stays
             in the foreground on the controlling terminal.

     -f devname
             Specify an alternate device file name, devname.

     -H      Start apmd in manual performance adjustment mode, initialising
             hw.setperf to 100.

     -L      Start apmd in manual performance adjustment mode, initialising
             hw.setperf to 0.

     -S sockname
             Specify an alternate socket name, sockname.  The socket is pro-
             tected to mode 0660, UID 0, GID 0; this protects access to sus-
             pend requests to authorized users only.

     -s      Current battery statistics are reported via syslog(3) and apmd
             exits without monitoring the APM status.

     -t seconds
             apmd periodically polls the APM driver for the current power
             state.  If the battery charge level changes substantially or the
             external power status changes, the new status is logged.  The
             polling rate defaults to once per 10 minutes, but may be speci-
             fied using the -t command-line flag.

     When a client requests a suspend or stand-by state, apmd does not wait
     for positive confirmation that the requested state has been entered be-
     fore replying to the client; to do so would mean the client does not get
     a reply until the system resumes from its sleep state.  Rather, apmd
     replies with the intended state to the client and then places the system
     in the requested state after running the configuration script and flush-
     ing the buffer cache.

     Actions can be configured for the following five transitions: suspend,
     standby, resume, powerup, and powerdown.  The suspend and standby actions
     are run prior to apmd performing any other actions (such as disk syncs)
     and entering the new state.  The resume program is run after resuming
     from a stand-by or suspended state.  The powerup and powerdown programs
     are run after the power status (AC connected or not) changes, as well as
     after a resume (if the power status changed in the mean time).

FILES
     /dev/apmctl           Default device used to control the APM kernel driv-
                           er.

     /etc/apm/suspend
     /etc/apm/standby
     /etc/apm/resume
     /etc/apm/powerup
     /etc/apm/powerdown    These files contain the host's customized actions.
                           Each file must be an executable binary or shell
                           script.  A single program or script can be used to
                           control all transitions by examining its argument
                           list, which is set to one of suspend, standby, re-
                           sume, powerup, or powerdown.

     /var/run/apmdev       Default UNIX-domain socket used for communication
                           with apm(8).

SEE ALSO
     syslog(3), apm(4), apm(8), sysctl(8)

     Advanced Power Management (APM) BIOS Interface Specification (revision
     1.2), Intel Corporation and Microsoft Corporation.

HISTORY
     The apmd command first appeared in NetBSD 1.3.  OpenBSD support was added
     in OpenBSD 1.2.

OpenBSD 4.7                    October 22, 2009                              2
