Add missing import and supported OS.

src/calibre/devices/cybookg3/driver.py

@@ -11,6 +11,7 @@ Device driver for Bookeen's Cybook Gen 3
 import os
 from itertools import cycle
 
+from calibre import islinux
 from calibre.devices.usbms.driver import USBMS
 import calibre.devices.cybookg3.t2b as t2b
 

src/calibre/devices/eb600/driver.py

@@ -101,7 +101,7 @@ class GER2(EB600):
 
     name = 'Ganaxa GeR2 Device Interface'
     gui_name = 'Ganaxa GeR2'
-    supported_platforms = ['windows']
+    supported_platforms = ['windows', 'linux']
 
     FORMATS = ['pdf']