---
name: "dwmmc"
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/dwmmc"
---

# dwmmc(4)

Synopsys DesignWare MMC/SD/SDIO controller

## NAME

**dwmmc** – Synopsys DesignWare MMC/SD/SDIO controller

## SYNOPSIS

**dwmmc\* at fdt?** **sdmmc\* at dwmmc?**

## DESCRIPTION

The **dwmmc** driver provides support for various MMC/SD/SDIO controllers based on the Synopsys DesignWare SD/eMMC core. These controllers are typically found on SoCs, such as the Rockchip RK3288/RK3399 and Samsung Exynos ARM SoCs.

The [sdmmc(4)](/sdmmc/4.md) subsystem performs SD/MMC transactions to communicate with whatever MMC/SD/SDIO devices are inserted into the card slot or directly connected to the controller.

## SEE ALSO

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

## HISTORY

OpenBSD support for **dwmmc** first appeared in OpenBSD 6.2.

## AUTHORS

The **dwmmc** driver was written by Mark Kettenis ⟨*kettenis@openbsd.org*⟩.