Adding --vid/--pid parameters.

Signed-off-by: Pol Henarejos <pol.henarejos@cttc.es>

README.md

@@ -1,6 +1,6 @@
 # Raspberry Pi Pico Random Number Generator
 
-** This fork includes an enhanced RNG to produce a true RNG. **
+**This fork includes an enhanced RNG to transform a Pico onto a true hardware RNG.**
 
 A basic random number generator that generates numbers from enviromental noise with the onboard DAC of the Raspberry Pi Pico. The project uses the Raspberry Pi Pico USB dev_lowlevel as a starting point. The Pico RNG is not meant to be FIPS 140-2 compliant as a stand-alone device by any means. However it does supply the Linux Kernel with random bits that is used with the appropriate entropy to achieve FIPS 140-2 compliant random numbers. Maybe one day the next gen Pico's will include an onboard crypto module.
 
@@ -89,8 +89,9 @@ Fig. 1 depicts the distribution of the bytes, from `0` to `255`. Ideally, it mus
 
 Fig. 2 depicts the distribution of chi square tests and excess percentages. Ideally, the distribution of chi square tests must follow a chi square distribution with mean at `255`. Excess percentage distribution must follow a uniform distribution.
 
-Pico-rng is also tested with `ent`, `rngtest` and `dieharder` tests. These are the results obtained with pico-rng:
+Pico-rng is also tested with `ent`, `rngtest`, `sp800-90b` and `dieharder` tests. These are the results obtained with pico-rng:
 
+### Ent
 ```
 $ ent sample.rng
 Entropy = 7.999999 bits per byte.
@@ -114,6 +115,7 @@ Serial correlation coefficient is 0.000006 (totally uncorrelated = 0.0).
 
 These results show that pico-rng is pretty random.
 
+### FIPS 140-2
 
 ```bash
 $ cat sample.rng | rngtest
@@ -140,6 +142,27 @@ In these results, we have a total number of trials `429496 (429141+355)`.
 - The acceptable result of Monobit test is `1` failed trial for every `9662` trials. For `429496` trials, the number of failed trials should be less than `429496/9662=44.45`.
 - The acceptable result of Poker test is `1` failed trial for every `10078` trials. For `429496` trials, the number of failed trials should be less than `42.62`.
 
+### SP800-90B
+
+SP800-90b is the superseded version of FIPS 140-2 (`rngtest`). Can be obtained from here [https://github.com/usnistgov/SP800-90B_EntropyAssessment](https://github.com/usnistgov/SP800-90B_EntropyAssessment).
+
+```bash
+$ ./ea-iid sample.rng
+Calculating baseline statistics...
+H_original: 7.995587
+H_bitstring: 0.999863
+min(H_original, 8 X H_bitstring): 7.995587
+** Passed chi square tests
+
+** Passed length of longest repeated substring test
+
+** Passed IID permutation tests
+```
+
+### Diehard
+
+It is a set of different tests.
+
 ```bash
 $ dieharder -a -g 201 -k 2 -Y 1 -m 2 -f sample.rng
 #=============================================================================#

firmware/CMakeLists.txt

@@ -2,7 +2,7 @@ add_executable(pico_rng
         pico_rng.c
         )
 
-target_link_libraries(pico_rng PRIVATE pico_stdlib hardware_resets hardware_irq hardware_adc)
+target_link_libraries(pico_rng PRIVATE pico_stdlib hardware_adc)
 
 pico_enable_stdio_uart(pico_rng 1)
 pico_add_extra_outputs(pico_rng)

firmware/pico_rng.c

@@ -33,6 +33,22 @@ static inline uint32_t board_millis(void)
     return to_ms_since_boot(get_absolute_time());
 }
 
+enum  {
+    BLINK_NOT_MOUNTED = (250 << 16) | 250,
+    BLINK_MOUNTED     = (250 << 16) | 250,
+    BLINK_SUSPENDED   = (500 << 16) | 1000,
+    BLINK_PROCESSING  = (50 << 16) | 50,
+
+    BLINK_ALWAYS_ON   = UINT32_MAX,
+    BLINK_ALWAYS_OFF  = 0
+};
+
+static uint32_t blink_interval_ms = BLINK_NOT_MOUNTED;
+
+void led_set_blink(uint32_t mode) {
+    blink_interval_ms = mode;
+}
+
 // Device descriptors
 #include "pico_rng.h"
 
@@ -521,6 +537,40 @@ void isr_usbctrl(void) {
     }
 }
 
+void led_blinking_task() {
+#ifdef PICO_DEFAULT_LED_PIN
+    static uint32_t start_ms = 0;
+    static uint8_t led_state = false;
+    static uint8_t led_color = PICO_DEFAULT_LED_PIN;
+#ifdef PICO_DEFAULT_LED_PIN_INVERTED
+    uint32_t interval = !led_state ? blink_interval_ms & 0xffff : blink_interval_ms >> 16;
+#else
+    uint32_t interval = led_state ? blink_interval_ms & 0xffff : blink_interval_ms >> 16;
+#endif
+
+
+    // Blink every interval ms
+    if (board_millis() - start_ms < interval)
+        return; // not enough time
+    start_ms += interval;
+
+    gpio_put(led_color, led_state);
+    led_state ^= 1; // toggle
+#endif
+}
+
+void led_off_all() {
+#ifdef PIMORONI_TINY2040
+    gpio_put(TINY2040_LED_R_PIN, 1);
+    gpio_put(TINY2040_LED_G_PIN, 1);
+    gpio_put(TINY2040_LED_B_PIN, 1);
+#else
+#ifdef PICO_DEFAULT_LED_PIN
+    gpio_put(PICO_DEFAULT_LED_PIN, 0);
+#endif
+#endif
+}
+
 /**
  * @brief EP0 in transfer complete. Either finish the SET_ADDRESS process, or receive a zero
  * length status packet from the host.
@@ -559,6 +609,7 @@ void ep0_out_handler(uint8_t *buf, uint16_t len) {
  * @param len the length of the random data in bytes
  */
 void get_random_data(char *buf, uint16_t len) {
+    led_set_blink(BLINK_PROCESSING);
     if (len > 64)
         len = 64;
     memset(buf, 0, len);
@@ -585,6 +636,7 @@ void get_random_data(char *buf, uint16_t len) {
         }
         memcpy(buf + i, &random_word, sizeof(random_word));
     }
+    led_set_blink(BLINK_MOUNTED);
 }
 
 /**
@@ -610,6 +662,22 @@ int main(void) {
     // Enable uart debug messages
     stdio_init_all();
 
+#ifdef PIMORONI_TINY2040
+    gpio_init(TINY2040_LED_R_PIN);
+    gpio_set_dir(TINY2040_LED_R_PIN, GPIO_OUT);
+    gpio_init(TINY2040_LED_G_PIN);
+    gpio_set_dir(TINY2040_LED_G_PIN, GPIO_OUT);
+    gpio_init(TINY2040_LED_B_PIN);
+    gpio_set_dir(TINY2040_LED_B_PIN, GPIO_OUT);
+#else
+#ifdef PICO_DEFAULT_LED_PIN
+    gpio_init(PICO_DEFAULT_LED_PIN);
+    gpio_set_dir(PICO_DEFAULT_LED_PIN, GPIO_OUT);
+#endif
+#endif
+
+    led_off_all();
+
     // ADC
     adc_init();
     adc_gpio_init(27);
@@ -623,6 +691,8 @@ int main(void) {
         tight_loop_contents();
     }
 
+    led_set_blink(BLINK_MOUNTED);
+
     // Populate the TX buffer
     get_random_data(ep1_buf, 64);
     usb_start_transfer(usb_get_endpoint_configuration(EP1_IN_ADDR), ep1_buf, 64);
@@ -630,6 +700,7 @@ int main(void) {
     // Everything is interrupt driven so just loop here
     while (1) {
         tight_loop_contents();
+        led_blinking_task();
     }
 
     return 0;

firmware/pico_rng_test.py

@@ -13,6 +13,8 @@ parser = argparse.ArgumentParser(description="Raspberry Pi Pico Random Number Ge
 parser.add_argument("--performance", action="store_true", help="Performance test the RNG.")
 parser.add_argument("--endless", action="store_true", help="Outputs random bytes endlessly.")
 parser.add_argument("--size", default="100", help="Number of bytes to output.")
+parser.add_argument("--vid", default="0000", help="VID.")
+parser.add_argument("--pid", default="0004", help="PID.")
 args = parser.parse_args()
 
 # If this is set, then the /dev/pico_rng file exists
@@ -24,7 +26,7 @@ if os.path.exists("/dev/pico_rng"):
 # File does not exist, test with usb.core
 if not rng_chardev:
     # Get the device
-    rng = usb.core.find(idVendor=0x0000, idProduct=0x0004)
+    rng = usb.core.find(idVendor=int(args.vid, base=16), idProduct=int(args.pid, base=16))
     assert rng is not None
 
     # Get the configuration of the device