---
name: "ichwd"
section: "4"
platform: "freebsd"
package: "base"
version: "16.0-CURRENT-20261027-61c70dc16a79"
release: "FreeBSD 16.0-CURRENT (2026-10-27)"
platforms: ["linux", "freebsd"]
url: "https://new.carta.tech/ichwd"
---

# ichwd(4)

device driver for the Intel ICH watchdog interrupt timer

## NAME

**ichwd** – device driver for the Intel ICH watchdog interrupt timer

## SYNOPSIS

To compile this driver into the kernel, place the following line in your kernel configuration file:

**device ichwd**

Alternatively, to load the driver as a module at boot time, place the following line in [loader.conf(5)](/loader.conf/5.md):

```
ichwd_load="YES"
```

## DESCRIPTION

The **ichwd** driver provides [watchdog(4)](/watchdog/4.md) support for the watchdog interrupt timer present on all Intel ICH motherboard chipsets.

The ICH WDT counts down in ticks of approximately 0.6 seconds; the exact value depends on hardware quality and environmental factors. Supported watchdog intervals range from 2 to 63 ticks.

In QEMU, there is a dedicated watchdog implementation for x86 systems based on the Intel 6300ESB controller hub. Support for this watchdog is provided by this kernel module.

Optionally, set the *hw.i6300esbwd.x.locked=1* [sysctl(8)](/sysctl/8.md) to prevent users from disabling the watchdog timeout check after it has been enabled.

Note that on some ICH-based systems, the WDT may be present but disabled, either in hardware or by the BIOS. The **ichwd** driver attempts to detect this condition and will refuse to attach if it believes the WDT is disabled.

## SEE ALSO

[watchdog(4)](/watchdog/4.md), [watchdog(8)](/watchdog/8.md), [watchdogd(8)](/watchdogd/8.md), [watchdog(9)](/watchdog/9.md) *Using the Intel ICH Family Watchdog Timer (WDT)*, Intel Application Note AP-725, Document Number 292273-001.

## HISTORY

The **ichwd** driver first appeared in FreeBSD 5.3.

## AUTHORS

The **ichwd** driver was written by Wm. Daryl Hawkins ⟨*dhawkins@tamu.edu*⟩ of Texas A&M University and Dag-Erling Smørgrav ⟨*des@FreeBSD.org*⟩. This manual page was written by Dag-Erling Smørgrav ⟨*des@FreeBSD.org*⟩.