.\" LP (Laptop Package)
.\"
.\" Copyright (c) 1994 by HOSOKAWA, Tatsumi <hosokawa@mt.cs.keio.ac.jp>
.\"
.\" This software may be used, modified, copied, and distributed, in
.\" both source and binary form provided that the above copyright and
.\" these terms are retained. Under no circumstances is the author
.\" responsible for the proper functioning of this software, nor does
.\" the author assume any responsibility for damages incurred with its
.\" use.
.\"
.Dd September 30, 2026
.Dt APM 4 amd64
.Os
.Sh NAME
.Nm apm
.Nd power management interface
.Sh DESCRIPTION
.Nm
is an interface to power management on i386 and amd64.
This interface was originally designed to support the Advanced Power Management
(APM) BIOS extension on i386.
However, the interface is now implemented by
.Xr acpi 4.
.Pp
.Nm
exports an application interface as a character device.
Applications such as
.Xr apm 8
can control APM, or retrieve APM status information via this interface.
The following
.Xr ioctl 2
commands are defined in
.In machine/apm_bios.h :
.Bl -tag -width 4n -offset indent
.It Sy APMIO_SUSPEND
Suspend system (typically using S3).
.It Sy APMIO_GETINFO
Get power management information.
.It Sy APMIO_STANDBY
Suspend system (typically using S1).
.It Sy APMIO_GETPWSTATUS
Get per battery information.
.El
.Sh FILES
.Bl -tag -width "/dev/apm" -compact
.It Pa /dev/apm
.El
.Sh SEE ALSO
.Xr apm 8 ,
.Xr zzz 8
.Sh AUTHORS
.An Tatsumi Hosokawa Aq Mt hosokawa@jp.FreeBSD.org