You might know about Codepack - it's hardware solution (implemented in PowerPC) for executable code compression (see some links below).

Is there any software tools that can decompress Codepack'ed code? Is there "strict" description of decompression algorithm? Thanks a lot.

http://www-306.ibm.com/chips/techlib/techlib.nsf/techdocs/852569B20050FF7785256993004F09F7
http://www.embedded.com/shared/printableArticle.jhtml?articleID=17701289