Rooting the ZenPad S 8.0 Z580CA tablet
The tablet in subject is a very slim and portable high resolution 8' 4:3 device by Asus. Different variants are available; here the model with an Intel Atom Z3560 and 2GB RAM / 16 GB SSD will be considered (full specifications: here).
Instructions are provided for a standard Linux desktop, in particular a Debian stable 8.3 distribution "Jessie". For Windows, see i.e. here. Japanese notes: here.
Connect the provided USB cable to an available desktop port, and verify that root can see the device: issue (as root) on a desktop terminal the command:
Reboot into the bootloader:
Verify that fastboot can still see the device:
# fastboot devices
If lsusb shows it but fastboot returns nothing, it can be a known issue with the utility version provided by the desktop Linux distribution is too old. Try a more recent one from Debian 'testing' for instance, or a recompiled i686 binary is provided here (mirror) from the XDA forum by senior developer Vampirefo (but beware of the security risks - safe hex is better! ;-).
Download on the desktop the last Intel Fastboot Tethered Temporary Recovery Session Launcher (FBRL; mirror here) and unpack it under /tmp/FBRL/.
Move to such directory and issue (as root) on a desktop terminal the following 4 commands:
# fastboot flash /tmp/recovery.zip recovery.zip
# fastboot flash /tmp/recovery.launcher recovery.launcher
# fastboot flash /system/bin/cp recovery.trigger.original
# fastboot oem backup_factory
... and check on the device screen that each one completes without problems. Select 'Reboot' to continue.
Insert a microSD card (important: make sure it is formatted as 'FAT32', not 'exFAT', for compatibility reasons: under Linux, the filesystem must be created with mkfs.vfat, not mkfs.exfat) in which the UPDATE-SuperSu-v2.46.zip binary
Select: Install zip, read it in from 'External SD', proceed with installation and then reboot into the new, rooted state.
Enjoy things like i.e. Linux Deploy for availability of a really open source, complete system!