ENVCTRL(4) | Device Drivers Manual (sparc64) | ENVCTRL(4)

# NAME

`envctrl` — Sun Ultra Enterprise 250 and 450 environmental monitoring

# SYNOPSIS

`envctrl* at ebus?`

# DESCRIPTION

The `envctrl` driver provides thermal monitoring of processors and power supplies, as well as automatic fan regulation. The driver attaches to the ‘`SUNW,envctrl`’ subsystem found on Ultra Enterprise 450 systems, and to the ‘`SUNW,envctrltwo`’ subsystem found on Ultra Enterprise 250 systems.

On Enterprise 450 systems, the following sensors can be queried with envstat(8):

Sensor | Units | Description
`CPU0` | degC | Processor 0 temperature
`CPU1` | degC | Processor 1 temperature
`CPU2` | degC | Processor 2 temperature
`CPU3` | degC | Processor 3 temperature
`PS0` | degC | Power supply 0 temperature
`PS1` | degC | Power supply 1 temperature
`PS2` | degC | Power supply 2 temperature
`ambient` | degC | Ambient temperature
`cpufan voltage` | V | Voltage used to drive processor fans
`psfan voltage` | V | Voltage used to drive power supply fans
`ps failed` | count | Number of failed power supplies
`fans failed` | count | Number of failed fans

whilst the following sensors can be queried on Enterprise 250 systems:

Sensor | Units | Description
`PDB` | degC | Power distribution board temperature
`SCSI` | degC | SCSI temperature
`CPUFAN` | V | CPU relative fan speed
`CPU0` | degC | Processor 0 temperature
`CPU1` | degC | Processor 1 temperature
`MB0` | degC | Motherboard temperature 0
`MB1` | degC | Motherboard temperature 1

# SEE ALSO

envsys(4), envstat(8)

# BUGS

Environmental interrupts are not supported.

July 24, 2026 | NetBSD 11.99