---
name: "obio"
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/obio"
---

# obio(4)

landisk onboard I/O bus device

## NAME

**obio** – landisk onboard I/O bus device

## SYNOPSIS

**obio0 at mainbus?**

## DESCRIPTION

The **obio** interface serves as an abstraction used by the autoconfiguration system to help find and attach devices (e.g. the disk controllers) connected to the landisk onboard I/O bus.

OpenBSD provides support for the following devices:

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

  power switch

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

  WD100x compatible hard disk controller driver

## SEE ALSO

[intro(4)](/intro/4.md), [mainbus(4)](/mainbus/4.md)

## HISTORY

The **obio** driver first appeared in OpenBSD 4.1.