apmd -- Advanced Power Management monitor daemon
apmd [-d] [-f -file] [-s] [-v]
The apmd utility monitors the occurrence of the specified Advanced Power
Management (APM) events and, if one of the events occurs, it executes the
sequence of commands corresponding to the event. Only the events specified
in the configuration file are notified to apmd; all other events are
ignored. For each event posted by the APM BIOS, apmd invokes the
sequence of commands specified in the configuration file. When apmd is
running with monitoring suspend/standby requests, the kernel will not
process those requests. Therefore, if you wish action to be taken when
these events occur, you need to explicitly configure the appropriate commands
or built-in functions in the configuration file.
The apmd utility recognizes the following runtime options:
-d Starts in debug mode. This causes apmd to execute in the foreground
instead of in daemon mode.
-f file Specifies a different configuration file file to be used in
place of the default /etc/apmd.conf.
-s Causes apmd to simulate a POWERSTATECHANGE event when a power
state change is detected (AC_POWER_STATE) but the bios of the
laptop doesn't report it. This enables you to do things like
dimming the LCD backlight when you unplug the power cord.
-v Verbose mode.
When apmd starts, it reads the configuration file (/etc/apmd.conf as
default) and notifies the set of events to be monitored to the APM device
driver. When it terminates, the APM device driver automatically cancels
monitored events.
If the apmd process receives a SIGHUP, it will reread its configuration
file and notify the APM device driver of any changes to its configuration.
The apmd utility uses the device /dev/apmctl to issue ioctl(2) requests
for monitoring events and for controlling the APM system. This device
file is opened exclusively, so only a single apmd process can be running
at any time.
When apmd receives an APM event, it forks a child process to execute the
commands specified in the configuration file and then continues listening
for more events. The child process executes the commands specified, one
at a time and in the order that they are listed.
While apmd is processing the command list for SUSPEND/STANDBY requests,
the APM kernel device driver issues notifications to APM BIOS once per
second so that the BIOS knows that there are still some commands pending,
and that it should not complete the request just yet.
The apmd utility creates the file /var/run/apmd.pid, and stores its
process id there. This can be used to kill or reconfigure apmd.
The structure of the apmd configuration file is quite simple. For example:
apm_event SUSPENDREQ {
exec "sync && sync && sync";
exec "sleep 1";
exec "zzz";
}
will cause apmd to receive the APM event `SUSPENDREQ' (which may be
posted by an LCD close), run the `sync' command 3 times and wait for a
while, then execute zzz (apm -z) to put the system in the suspend state.
+o The apm_event keyword
`apm_event' is the keyword which indicates the start of configuration
for each events.
+o APM events
If you wish to execute the same commands for different events,
the event names should be delimited by a comma. The following
are valid event names:
- Events ignored by the kernel if apmd is running:
STANDBYREQ
USERSTANDBYREQ
SUSPENDREQ should include sync in the command list,
USERSUSPENDREQ should include sync in the command list,
BATTERYLOW only zzz should be specified in the command
list.
- Events passed to apmd after kernel handling:
NORMRESUME
CRITRESUME
STANDBYRESUME
POWERSTATECHANGE
UPDATETIME
CAPABILITIESCHANGE
Other events will not be sent to apmd.
+o command line syntax
In the example above, the three lines beginning with `exec' are
commands for the event. Each line should be terminated with a
semicolon. The command list for the event should be enclosed
by `{' and `}'. The apmd utility uses /bin/sh for double-quotation
enclosed command execution, just as with system(3).
Each command is executed in order until the end of the list is
reached or a command finishes with a non-zero status code. The
apmd utility will report any failed command's status code via
syslog(3) and will then reject the request event posted by the
APM BIOS.
+o Built-in functions
You can also specify apmd built-in functions instead of command
lines. A built-in function name should be terminated with a
semicolon, just as with a command line. The following built-in
functions are currently supported:
- reject:
Reject last request posted by APM BIOS. This can be used
to reject a SUSPEND request when the LCD is closed and
put the system in a STANDBY state instead.
Sample configuration commands include:
apm_event SUSPENDREQ {
exec "/etc/rc.suspend";
}
apm_event USERSUSPENDREQ {
exec "sync && sync && sync";
exec "sleep 1";
exec "apm -z";
}
apm_event NORMRESUME, STANDBYRESUME {
exec "/etc/rc.resume";
}
# resume event configuration for serial mouse users by
# reinitializing a moused(8) connected to a serial port.
#
#apm_event NORMRESUME {
# exec "kill -HUP `cat /var/run/moused.pid`";
#}
#
# suspend request event configuration for ATA HDD users:
# execute standby instead of suspend.
#
#apm_event SUSPENDREQ {
# reject;
# exec "sync && sync && sync";
# exec "sleep 1";
# exec "apm -Z";
#}
/etc/apmd.conf
/dev/apmctl
/var/run/apmd.pid
apm(4), apm(8)
Mitsuru IWASAKI <[email protected]>
KOIE Hidetaka <[email protected]>
Some contributions made by
Warner Losh <[email protected]>,
Hiroshi Yamashita <[email protected]>,
Yoshihiko SARUMARU <[email protected]>,
Norihiro Kumagai <[email protected]>,
NAKAGAWA Yoshihisa <[email protected]>, and
Nick Hilliard <[email protected]>.
The apmd utility appeared in FreeBSD 3.3.
FreeBSD 5.2.1 June 28, 1999 FreeBSD 5.2.1 [ Back ] |
