Hello.
    On my HP EliteBook laptop, where I've just upgraded from
Debian-Wheezy to Devuan-Jessie, the SD cards don't show up on the Xfce
desktop, while USB devices still do.
    I have checked that  /dev/mmcblk0p1 is created - when there is only
one partition.
    On my HP desktop with the same OS, installed ~ a year ago, it is
even worse: the device isn't created.
    It worked out-of-the-box on Wheezy.
    Any clue?
                        Didier