/* 4. Register char device */ ret = alloc_chrdev_region(&dev_num, 0, 1, "sec_testbd"); if (ret) return ret; cdev_init(&testbd->cdev, &sec_testbd_fops); testbd->cdev.owner = THIS_MODULE; ret = cdev_add(&testbd->cdev, dev_num, 1); if (ret) goto err_unregister;
| Parameter | Meaning | |-----------|---------| | mode | 0 = buffer‑overflow test, 1 = timing jitter, 2 = fault‑injection | | iterations | Number of stress cycles (max 10 000) | | seed | Pseudo‑random seed for pattern generation | Sec S3c2443x Test B D Driver
During stress runs, the driver logs timestamps to /sys/kernel/debug/sec_testbd/stress_log for offline analysis. | Test | Throughput (DMA) | Latency (Crypto) | Power (mW) | |------|------------------|------------------|------------| | 1 GiB secure copy | 1.84 GB/s | – | 120 | | AES‑256‑ECB (256 MiB) | – | 3.2 µs/KB | 95 | | SHA‑256 (1 GiB) | – | 1.1 µs/KB | 88 | | Stress mode 0 (10 k iter) | 0.9 GB/s (average) | – | 130 | if (ret) return ret