---
name: "fhc"
section: "4"
platform: "openbsd"
package: "man"
version: "8.0-current-20261101"
release: "OpenBSD 8.0-current (2026-11-01)"
platforms: ["openbsd"]
url: "https://new.carta.tech/fhc"
---

# fhc(4)

SPARC64 FireHose controller

## NAME

**fhc** – SPARC64 FireHose controller

## SYNOPSIS

**fhc\* at central?** **fhc\* at mainbus0**

## DESCRIPTION

The **fhc** device provides support for the FireHose controllers found on Sunfire, Starfire, and Wildfire UltraSPARC systems. These devices are used for board level functions on these systems. This device also controls an LED for each slot. This LED can be made to blink based on the load average on most systems by setting the [sysctl(2)](/sysctl/2.md) variable *machdep.led\_blink* to a non-zero value.

## HARDWARE

OpenBSD includes the following **fhc** drivers, sorted by driver name:

- [clkbrd(4)](/clkbrd/4.md)

  SPARC64 Clock Board

- [clock(4)](/clock/4.md)

  real-time clock

- [environ(4)](/environ/4.md)

  SPARC64 temperature sensor

- [zs(4)](/zs/4.md)

  Zilog 8530 (ZSCC) serial communications driver

## SEE ALSO

[sysctl(2)](/sysctl/2.md), [central(4)](/central/4.md), [intro(4)](/intro/4.md)

## HISTORY

OpenBSD support for the **fhc** first appeared in OpenBSD 3.7.