nvram(4)

nvram4

Driver for reading pc nvram contents

Usage

pseudo-device nvram 1

Overview

The nvram device provides read-only access to the non-volatile memory contained in the MC146818 real-time clock.

This data is provided as a seekable character device, /dev/nvram. Checksums of the NVRAM contents are calculated over bytes 2 to 31 and stored in byte 32. A valid checksum is required for the driver to initialize.

Files

/dev/nvram

History

nvram support was originally included in OpenBSD 3.7.

From man 8.0-current-20261101 in OpenBSD 8.0-current (2026-11-01). Parsed by carta from the page's mdoc source.