Pascal isn't ideal, but it has derivatives which are.
Pascal became Modula-2, in which several large-scale OS implementation efforts were made, including Acorn ARX.
Modula-2 became Oberon, which is an OS: https://news.ycombinator.com/item?id=15753138
There is also Euclid, which was used to implement a Unix. Yes, a Unix in Pascal. https://en.wikipedia.org/wiki/TUNIS