ARM9 SystemReady is designed to offer manufacturers of devices a way to target a "reference platform", where all compliant devices can be booted from a single kernel/os image. I detailed this out in a comment earlier this week, with PDF links, if you'd like to read more. I think they're specifically thinking of mobile phones and servers (and the Server spec is its own standalone thing, which is smart). https://news.ycombinator.com/item?id=26694321