Mounting an SD Card

Due to limited onboard resources, external files are usually recommended to be stored on an SD card. This chapter describes how to mount an SD card.

  • Create the SD card mount point

    mkdir -p /sd_card

  • View the SD card device node

    ls /dev/mmc*

    Expected output:

    mmcblk1    mmcblk1p1

    Where:

    • /dev/mmcblk1 represents the entire MMC/SD card device.
    • /dev/mmcblk1p1 represents the first partition on this card.

  • Mount the SD card

    mount /dev/mmcblk1p1 /sd_card

  • Check whether the mount succeeded

    df -h | grep sd_card

    Expected output:

    / # df -h | grep /sd_card
/dev/mmcblk1p1           14.8G     56.1M     14.8G   0% /sd_card
/ #

    If the output contains /sd_card, the mount succeeded. You can now copy external files into this directory for storage and use.

  • Unmount the SD card

    After finishing file read/write, unmount the SD card before removing the media to avoid data corruption.

    umount /sd_card

    To remount, run the mount command again.