---
name: "iosf"
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/iosf"
---

# iosf(4)

Intel OnChip System Fabric device

## NAME

**iosf** – Intel OnChip System Fabric device

## SYNOPSIS

**iosf\* at acpi?** **iosf\* at pci?**

## DESCRIPTION

The **iosf** driver provides support routines for platforms using the Intel OnChip System Fabric.

The [dwiic(4)](/dwiic/4.md) driver uses the MailBox Interface (MBI) provided by **iosf** to coordinate access to I2C devices.

## SEE ALSO

[acpi(4)](/acpi/4.md), [dwiic(4)](/dwiic/4.md), [pci(4)](/pci/4.md)

## HISTORY

The **iosf** device driver first appeared in OpenBSD 7.4.

## AUTHORS

The **iosf** driver was written by David Gwynne ⟨*dlg@openbsd.org*⟩.