Where does “rotulus” come from?

rotulus (Latin) comes from Latin rotula, from Arabic رَطْل, from Classical Syriac ܪܝܛܠܐ, from Classical Syriac ܠܝܛܪܐ, from French litre, from Medieval Latin litra, from Ancient Greek λίτρα, from Proto-Italic *līðrā — ingot.

rotulus (Latin): Alternative form of rotula; roll; roll of paper