It's Free Real Estate

A firmware engineer at Oxide Computer describes how they reduced flash memory usage in their Hubris-based embedded OS from 96% to 68% occupancy. The key insight was generalizing MPU flash region allocation from a fixed single region per task to N regions, allowing each task to use all spare MPU slots for flash. By splitting each task's flash size into a sum of N powers of two and packing them with a simple alignment heuristic, they eliminated 280 KiB of padding (from 341 KiB down to 60 KiB) at essentially zero runtime cost. The change was significant enough to the system's internals that it later caused an unexpected network switch failure.