Technological advancements in computer hardware and software have made embeddedsystems highly affordable and widely used. Consumers have ever increasing demandsfor powerful embedded devices such as cell phones, PDAs and media players. Suchcomplex and feature-rich embedded devices are strictly limited by their battery life-time. Embedded systems typically are diskless and use flash for secondary storagedue to their low power, persistent storage and small form factor needs. The energyefficiency of a processor and flash in an embedded system heavily depends on thechoice of file system in use. To address this problem, it is necessary to provide sys-tem developers with energy profiles of file system activities and energy efficient filesystems. In the first part of the thesis, a macro-model for the CRAMFS file systemis established which characterizes the processor and flash energy consumption due tofile system calls. This macro-model allows a system developer to estimate the energyconsumed by CRAMFS without using an actual power setup. The second part ofthe thesis examines the effects of using non-volatile memory as a write-behind bufferto improve the energy efficiency of JFFS2. Experimental results show that a 4KBwrite-behind buffer significantly reduces energy consumption by up to 2-3 times forconsecutive small writes. In addition, the write-behind buffer conserves flash spacesince transient data may never be written to flash.
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