Code compression for embedded systems

Memory is one of the most restricted resources in many modern embedded systems. Code compression can provide substantial savings in terms of size. In a compressed code CPU, a cache miss triggers the decompression of a main memory block, before it gets transferred to the cache. Because the code must be decompressible starting from any point (or at least at cache block boundaries), most file-oriented compression techniques cannot be used. We propose two algorithms to compress code in a space-efficient and simple to decompress way, one which is independent of the instruction set and another which depends on the instruction set. We perform experiments on true instruction sets, a typical RISC (MIPS) and a typical CISC (x86) and compare our results to existing file-oriented compression algorithms.