November 9, 2008 ACPITZ 4

### NAME

acpitz - ACPI Thermal Zone

### SYNOPSIS

acpitz* at acpi?

### DESCRIPTION

The acpitz driver supports ACPI Thermal Zones.

The temperature can be monitored by the envsys(4) API or the envstat(8) command.

### EVENTS

The acpitz driver knows about the active cooling levels, the current temperatures, and critical, hot, and passive temperature thresholds (as supported by the hardware). The driver is able to send events to powerd(8) when the sensor's state has changed. When a Thermal Zone is critical, a critical-over event will be sent or if the Thermal Zone is hot, a warning-over event will be sent to the ```/etc/powerd/scripts/sensor_temperature` script.

The critical temperature is the threshold for system shutdown. Depending on the hardware, the mainboard will take down the system instantly and no event will have a chance to be sent. The passive temperature is the passive cooling temperature threshold. Passive cooling means the Thermal Zone hardware doesn't have any software control. On capable hardware, active cooling can power on and off fans, for example.

### SEE ALSO

acpi(4), envsys(4), envstat(8), powerd(8)

### HISTORY

The acpitz driver appeared in NetBSD2.0.

### BUGS

Any policy control such as fan control is not implemented.