PMU(4)							   BSD Kernel Interfaces Manual 						    PMU(4)

NAME

     pmu -- support for Power Management Units found in all Apple laptops and some desktop Power Macintosh computers

SYNOPSIS

     pmu* at obio?
     nadb* at pmu?
     battery* at pmu?
     smartbat* at pmu?

DESCRIPTION

     The pmu driver provides support for the Power Management Unit found in Apple laptops and some desktop Power Macintosh computers.  Functions
     controlled by the PMU include the real time clock, ADB, power, batteries, on some laptops like the PowerBook 3400c and similar machines it
     also controls hotkeys and display brightness, on others it provides an iic(9) bus and on some it controls CPU speed.  On many older machines
     it also provides access to some non-volatile memory and thermal sensors.  Not all those features are present on all machines, for instance
     Power Macintosh G4 and later machines don't have ADB, many more recent laptops have display brightness and backlight control built into the
     graphics controller instead of the PMU, only a few older PowerBooks use the PMU for CPU speed control and newer machines use a different way
     to access non-volatile memory.  However, all known PMUs so far provide a real time clock and power control.

   Notes by model
     Real time clock and power control are present and supported on all machines that can run NetBSD/macppc, ADB is supported when present.

     PowerBook 2400, 3400c, and 3500
		   Battery status and thermal sensors found on the mainboard and in the battery pack are supported by the battery(4) driver, val-
		   ues can be read via envsys(4).  Hotkeys for brightness control are supported, CPU speed control and parameter RAM are present
		   but unsupported.

     Power Macintosh G4
		   ADB is not present, iic(9) is present but unsupported.

SEE ALSO

     battery(4), cuda(4), nadb(4), nvram(4), obio(4), iic(9)

BUGS

     Some features are currently unsupported, like the iic(9) bus, access to parameter RAM and CPU speed control.

BSD
								   May 14, 2007 							       BSD