Home
QNX Software Development Platform
QNX SDP is a cross-compiling and debugging environment, including an IDE and command-line tools, for building binary images and programs for target boards running the QNX OS 8.0.
Utilities & Libraries
Devctl and Ioctl Commands
DCMD_SDIO_*
DCMD_SDIO_ATTACH_DEVICE
Attach a device

QNX Momentics IDE User's Guide
This User's Guide describes version 8.0 of the Integrated Development Environment (IDE) that's part of the QNX Tool Suite.
QNX Software Development Platform
QNX SDP is a cross-compiling and debugging environment, including an IDE and command-line tools, for building binary images and programs for target boards running the QNX OS 8.0.
- Quickstart Guide
- System Architecture
  The System Architecture guide accompanies the QNX OS and is intended for both application developers and end-users.
- OS Components & Operations
- Graphics
- Programming
- System Security Guide
  The QNX System Security Guide is intended for both system integrators who are responsible for the security of a QNX OS system and developers who want to create a QNX OS resource manager free from vulnerabilities.
- Utilities & Libraries
  - C Library Reference
  - Devctl and Ioctl Commands
    - BIOC*
    - CAN_DEVCTL_*
    - DCMD_ALL_*
    - DCMD_BLK_*
    - DCMD_CAM_*
    - DCMD_CHR_*
    - DCMD_DUMPER_*
    - DCMD_F3S_*
    - DCMD_FSYS_*
    - DCMD_IP_*
    - DCMD_MEMMGR_*
    - DCMD_MISC_*
    - DCMD_MMCSD_*
    - DCMD_PROC_*
    - DCMD_PROF_*
    - DCMD_PTPD_*
    - DCMD_SDIO_*
      - DCMD_SDIO_ATTACH_DEVICE
        Attach a device
      - DCMD_SDIO_CFG_IOMEM
        Configure I/O memory
      - DCMD_SDIO_CLR_IOREG
        Clear some bits in an I/O register
      - DCMD_SDIO_DETACH_DEVICE
        Detach a device
      - DCMD_SDIO_DEV_START
        Start a device handler
      - DCMD_SDIO_DEV_STOP
        Stop a device handler
      - DCMD_SDIO_GET_HCCAP
        Get the host controller capabilities
      - DCMD_SDIO_INTR_DISABLE
        Disable a function interrupt
      - DCMD_SDIO_INTR_ENABLE
        Enable a function interrupt
      - DCMD_SDIO_READ_IOREG
        Read an I/O register
      - DCMD_SDIO_SET_IOREG
        Set some bits in an I/O register
      - DCMD_SDIO_SHMEM_FINI
        Unmap the device's shared memory object
      - DCMD_SDIO_SHMEM_INIT
        Initialize the device's shared memory object
      - DCMD_SDIO_VENDOR
        Execute a vendor-specific command
      - DCMD_SDIO_WRITE_IOREG
        Write to an I/O register
    - DCMD_SDMMC_*
    - DCMD_SPI_*
    - PTP_*
    - FIO*
    - TC*
    - TIOC*
  - JSON Library Reference
  - PAM Reference
  - QNX Helpers Developer's Guide
    These libraries provide QNX helpers, including helpers that assist with logging, string conversion, and number and type sizes.
  - SPI Framework Technote
  - QNX Cryptography Library
    The QNX Cryptography Library (qcrypto) is a flexible cryptography framework that allows you to choose which cryptography provider responds to requests on a per-process basis.
  - QNX devcrypto Service
  - Utilities Reference
  - WPA Control Interface Reference
    This document provides a reference for the Wi-Fi Protected Access (WPA) control interface, which provides a C API for the WPA/IEEE 802.11i protocols in Wi-Fi client stations. Application developers who want to control WPA operations and get associated status and event data should read this reference.
- Migrating to QNX OS 8.0
QNX Software in the Cloud
QNX Software in the Cloud enables developers to use the QNX OS in the Amazon cloud environment.
QNX Toolkit for Visual Studio Code
This User's Guide describes the QNX^® Toolkit for Visual Studio Code. The guide introduces you to the QNX Toolkit by explaining the QNX development environment and how to build, run, and debug your QNX^® Operating System (OS) applications and systems.
QNX Hypervisor User's Guide
This User's Guide explains the QNX hypervisor architecture and provides instructions for installing and running a QNX Hypervisor system, changing system components and configuration, and using hypervisor features such as virtual devices (vdevs).
Typographical Conventions, Support, and Licensing
This section describes the typographical conventions used throughout the documentation, explains how to obtain technical support, and provides some information about licensing.

DCMD_SDIO_ATTACH_DEVICE

QNX SDP8.0Devctl and Ioctl CommandsDeveloper

Attach a device

Synopsis:

#include <mmc/sdio.h>

#define DCMD_SDIO_ATTACH_DEVICE   __DIOTF(_DCMD_MISC, 0x12, sdio_dev_t)

Arguments to devctl():


Argument	Value
`filedes`	A file descriptor that you obtained by opening the device
`dcmd`	DCMD_SDIO_ATTACH_DEVICE
`dev_data_ptr`	A pointer to a sdio_dev_t
`n_bytes`	`sizeof(sdio_dev_t)`
`dev_info_ptr`	NULL

Description:

This command attaches a device. The sdio_dev_t structure is defined as follows:

typedef struct _sdio_dev_t {
        uint16_t        vid;    /* Vendor ID */
        uint16_t        did;    /* Device ID */
        uint16_t        ccd;    /* Class code */
        int16_t         fun;    /* Function number */
} sdio_dev_t;

Input:

Fill in the members as required. You must specify the vendor and device IDs. If you specify SDIO_FUNC_ANY for the function number, you can't specify SDIO_CLASS_ANY for the class code.

Output:

Whichever of the function or class code that you didn't specify is filled in.

See also:

DCMD_SDIO_DETACH_DEVICE

devctl() in the QNX OS C Library Reference

Page updated: August 11, 2025