portfs
static int64_t portfs(int, uintptr_t, uintptr_t, uintptr_t, uintptr_t,
(int (*)())(uintptr_t)portfs,
error = portfs(PORT_GET, a0, a1, (int)a2, (int)a3, a4);
error = portfs(opcode, (uint32_t)a0, a1, a2, a3, a4);
error = portfs(opcode, a0, a1, a2, a3, a4);