mpu_setup_region
err |= mpu_setup_region(region++, 0, 32,
err |= mpu_setup_region(region++, xip[i].base, ilog2(xip[i].size),
err |= mpu_setup_region(region++, mem[i].base, ilog2(mem[i].size),
err |= mpu_setup_region(region++, vectors_base, ilog2(2 * PAGE_SIZE),