DocumentCode :
3504502
Title :
Memory Footprint Reduction with Quasi-Static Shared Libraries in MMU-less Embedded Systems
Author :
Lee, Jaesoo ; Park, Jiyong ; Hong, Seongsoo
Author_Institution :
Seoul National University, South Korea
fYear :
2006
fDate :
04-07 April 2006
Firstpage :
24
Lastpage :
36
Abstract :
Despite a rapid decrease in the price of solid state memory devices, system memory is still a very precious resource in embedded systems. The use of shared libraries is known to be effective in significantly reducing memory usage. Unfortunately, many resource-constrained embedded systems lack MMU, making it extremely difficult to support this technique. To address this problem, we propose a novel shared library scheme called the quasi-static shared library. In quasi-static shared libraries, global symbols are bound to pseudo-addresses at linking time and the actual physical addresses are bound at loading time. This scheme is made possible by emulating MMU’s memory mapping feature with a Data Section Base Register (DSBR) and a Data Section Base Table (DSBT). Quasi-static shared libraries do not require symbol tables which take up time and space at runtime. We have implemented the proposed scheme in a commercial ADSL (Asymmetric Digital Subscriber Line) home network gateway and conducted a series of experiments measuring its memory usage and performance overhead. The result is drastic: a 35% reduction in flash memory usage and a 10% reduction in RAM usage. These results were achieved with only a negligible performance penalty of less than 4%. Even though this scheme was applied to uClinux-based embedded systems, it can be used for any MMU-less real-time operating system.
Keywords :
DSL; Embedded system; Flash memory; Home automation; Joining processes; Random access memory; Registers; Runtime library; Software libraries; Solid state circuits;
fLanguage :
English
Publisher :
ieee
Conference_Titel :
Real-Time and Embedded Technology and Applications Symposium, 2006. Proceedings of the 12th IEEE
ISSN :
1545-3421
Print_ISBN :
0-7695-2516-4
Type :
conf
DOI :
10.1109/RTAS.2006.26
Filename :
1613320
Link To Document :
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