---
name: "ioapic"
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/ioapic"
---

# ioapic(4)

I/O Advanced Programmable Interrupt Controller

## NAME

**ioapic** – I/O Advanced Programmable Interrupt Controller

## SYNOPSIS

**ioapic0 at mainbus0**

## DESCRIPTION

**ioapic** is an I/O Advanced Programmable Interrupt Controller (APIC). It provides interrupt management for systems with multiple I/O subsystems and can distribute interrupts across multiple processors.

## SEE ALSO

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

## STANDARDS

**ioapic** is based on Intel's 82093AA I/O Advanced Programmable Interrupt Controller (I/O APIC) specification.

## HISTORY

The **ioapic** driver first appeared in OpenBSD 3.5.

## AUTHORS

The **ioapic** driver was written by Bill Sommerfield.