Those stacks can be full of 'not invented here'. They are unique and have their own quirks. Quirks that you more than likely can not google for any sort of guidance as to what is going on. I wrote one of those stacks a few years ago. No std libs at all. Why? must fit in 32k and most of that space is needed to hold data. That means throwing a lot of those helper bits out or spend weeks figuring out how to bend the compiler to your will and not include everything. When it is easier just to roll your on CS version of whatever. But it sucks because you probably have odd edge cases.