35/2008 : Embedded JIT Compilation with CACAO on YARI

RR Number

35/2008

Author(s)

Florian Brandner, Tommy Thorn, Martin Schoeberl

Abstract

Java is one of the most popular programming languages for the development of portable workstation and server applications available today. Because of its clean design and typesafety, it is also becoming attractive in the domain of embedded systems. Unfortunately, the dynamic features of the language and its rich class library cause considerable overhead in terms of runtime and memory consumption. Efficient techniques to implement Java Virtual Machines (JVM), that are suitable for use in resource constrained environments are thus needed. In this work we present a solution for very restricted environments based on CACAO. CACAO is a just-in-time (JIT) compiling JVM implementation, combining high speed and small size. We have modified the original JVM to run without an underlaying operating system within only 1~MB of memory. In addition we present a new technique to selectively precompile methods during the initialization phase of real-time Java applications to prevent unwanted interaction between the JIT compilation and critical tasks. Furthermore we present the YARI soft-core as the execution platform of CACAO within an FPGA. We compare our implementation with two well known Java processors, JOP and Sun's picoJava-II, on the same FPGA technology. Although JOP achieves a higher clock frequency and picoJava-II occupies nearly 4 times the resource of YARI, our solution is capable to outperform both of them by a factor of up to 2.2 and 1.7 respectively.

Bibtex

@TECHREPORT{cacao:yari:techrep,
  author = {Florian Brandner and Tommy Thorn and Martin Schoeberl},
  title = {Embedded {JIT} Compilation with {CACAO} on {YARI}},
  institution = {Institute of Computer Engineering, Vienna University of Technology},
  year = {2008},
  number = {RR 35/2008},
  address = {Austria},
  month = {June},
}

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