Sun eventually did JavaOS, though I'm not sure how much of its code was Java.
IBM did Jikes RVM (old name: Jalapeno) which was mostly, if not purely Java. They handled the bootstrapping problem with some clever ahead-of-time compilation + meta-programming. Even their GC is implemented in Java.
IBM did Jikes RVM (old name: Jalapeno) which was mostly, if not purely Java. They handled the bootstrapping problem with some clever ahead-of-time compilation + meta-programming. Even their GC is implemented in Java.