Totally tangential, but I've been meaning to find out. I infer from your post, Mark, that System.map is a map to the symbols in the kernel binary (Edit: which would have been obvious if I'd ever looked at the file, something I can't believe I never did in the last ten years). Is it useful for anything else? I've always really meant to find out, but never bothered, and now seems like as good a time as any, since we have an expert on hand.