---
name: "sdmmc"
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/sdmmc"
---

# sdmmc(4)

SD bus

## NAME

**sdmmc** – SD bus

## SYNOPSIS

**# arm64** **sdmmc\* at amlmmc?** **sdmmc\* at bcmsdhost?** **sdmmc\* at dwmmc?** **sdmmc\* at imxesdhc?** **sdmmc\* at sximmc?**

**# armv7** **sdmmc\* at bcmsdhost?** **sdmmc\* at dwmmc?** **sdmmc\* at imxesdhc?** **sdmmc\* at mvpxa?** **sdmmc\* at ommmc?** **sdmmc\* at sximmc?**

**# octeon** **sdmmc\* at octmmc?**

**# riscv64** **sdmmc\* at cdsdhc?** **sdmmc\* at dwmmc?**

**# sparc64** **sdmmc\* at wbsd?**

**# all architectures** **sdmmc\* at rtsx?** **sdmmc\* at sdhc?**

## DESCRIPTION

The **sdmmc** subsystem provides machine-independent bus support and drivers for SD/MMC devices.

Standard SD/SDHC memory devices will show up as a fake SCSI disk, using scsibus(4) and [sd(4)](/sd/4.md).

## SEE ALSO

[intro(4)](/intro/4.md), [rtsx(4)](/rtsx/4.md), scsibus(4), [sd(4)](/sd/4.md), [sdhc(4)](/sdhc/4.md)

## HISTORY

The **sdmmc** driver first appeared in OpenBSD 4.0.

## AUTHORS

The **sdmmc** driver was written by Uwe Stuehler ⟨*uwe@openbsd.org*⟩.