void avoid_ram( paddr32_t start,
                size_t size);

Make startup avoid using the specified RAM for any of its internal allocations. Memory remains available for procnto to use. This function is useful for specifying RAM that the IPL/ROM monitor needs to keep intact while startup runs. Because it takes only a paddr32_t, addresses can be specified in the first 4 GB. It doesn't need a full paddr_t because startup will never use memory above 4 GB for its own storage requirements.