If problem dsl-linux.sh will not execute:

There is an option to mount called "exec" it allows execution of files within the file system. 
Apparently it is not a default option to have on when mount vfat (unsurprisingly).

So to mount your usb drive:
mount -t vfat -o <your other options>,exec <your device> <your mount point>

e.g.
mount -t vfat -o rw,exec /dev/sda1 /mnt/usb

Or in fstab...
/dev/sda1 /mnt/usb vfat noauto,user,rw,exec 0 0

Then dsl-linux.sh worked!
