SD device drivers issue commands to the host controller by calling the SD bus library routines, and then the library generates the appropriate SD commands for the host controller. SD device drivers cannot directly access the host-controller register set, nor can they embed pass-through commands for the host controller in I/O request packets (IRPs). The following diagram depicts the SD driver stack that the system creates when it enumerates an SD controller and accompanying cards: SD drivers must link to this library when they compile. If a user inserts an SD card with a different kind of function, such as GPS or wireless LAN, Windows loads a vendor-supplied driver for the device.Īll device drivers in the SD stack, whether native or vendor-supplied, must communicate with the SD bus driver by calling routines in the static SD bus library ( sdbus.lib). If a user inserts an SD memory card, Windows loads a native SD storage class driver ( sffdisk.sys) and storage miniport driver ( sffp_sd.sys) on top of the bus driver. When the system enumerates an SD host controller, it loads a native SD bus driver ( sdbus.sys). The operating system provides support for SD host controllers that connect directly to the PCI bus. Windows manages these devices with the USB mass storage driver ( usbstor.sys) and the native storage class driver ( disk.sys), as depicted in the following diagram:įor a more complete description of the device stack that Windows creates for a memory card that connects to the USB bus, see Device Object Example for a USB Mass Storage Device. This document explains how the operating system supports the card function extensions to SD technology.Ĭard readers for many early SD storage devices were designed to connect to the USB bus. Secure Digital (SD) card technology began with portable, miniature memory cards, but with the release of the Secure Digital I/O (SDIO) specification, the Secure Digital Association (SDA) has broadened the definition of SD technology to include a large variety of card functions, such as Bluetooth devices, video cameras, Wireless LAN devices, and Global Positioning System (GPS) receivers.

Intel sd host controller driver