Usage:
mount [-lhV]
mount -a [options]
mount [options] [--source] <source> | [--target] <directory>
mount [options] <source> <directory>
mount <operation> <mountpoint> [<target>]
I created the Steam folder right in the SD card. And no, I didn't eject the card. I'm not used to ejecting stuff, as I just assume it's not in use after a couple minutes of inactivity.
And why was it mounted in a different directory (/mnt), when I specified /mnt/sd in the terminal command?
Wait. It's mounted in /mnt/sd now. But I don't understand how to make it get that name instead of "Library" which is the partition's name. If I unmount and mount it using the Disks app, it does get the "Library" name and a nice SD card icon.
Update.
I messed around with the mount options in the Disks app and managed to give it a display name and icon.
But the main problem is still there.
Clicking the SD card simply shows a "loading" animation next to it for like a tenth of a second, and never actually opens the SD card in the files explorer.
How would I boot into Linux with secure boot enabled?
Anyway, while the card works fine now, removing it and inserting it again created a second mounting point called "Library1" (original was Library), and both of them show up in the files explorer.
You can test using Zorin OS with Secure Boot enabled - you may need to set up some mok-utils... But most users don't have too much trouble.
The issues caused by Secure Boot stem from the fact that Microsoft signed off on most Linux applications to allow Secure Boot to pass them through - but not all applications.
Users not using those unsigned apps have no trouble.
Those that do happen to use those unsigned apps run into trouble if they are also using secure boot.