Call POST / ao_trng_reset() lazily

renamed ao_reset() to ao_trng_reset() and
  ao_status() to ao_trng_status()
moved the failure handling to ao_trng_failure()

CAUTION: this version 1.6.3 will fail to load the command processor!

diff --git a/src/drivers/ao_trng.c b/src/drivers/ao_trng.c
index b8e25e289c01dcc21ded0f02211372174f176fa9..d3c2823a50d180249d19559107e5f8e8f148e86b 100644 (file)
--- a/src/drivers/ao_trng.c
+++ b/src/drivers/ao_trng.c
@@ -20,23 +20,6 @@
 #include <ao_crc.h>
 #include <ao_trng.h>
 
-
-static struct ao_task ao_blink_red_task;
-static uint8_t ao_failed = 0;
-
-static void
-ao_blink_red(void)
-{
-       for (;;) {
-               while (!ao_failed)
-                       ao_sleep(&ao_failed);
-               while (ao_failed) {
-                       ao_led_toggle(AO_LED_RED);
-                       ao_delay(AO_MS_TO_TICKS(500));
-               }
-       }
-}
-
 static struct ao_task ao_blink_green_task;
 static uint8_t ao_blinking_green = 0;
 
@@ -63,86 +46,31 @@ ao_blink_green_toggle(void)
        ao_wakeup(&ao_blinking_green);
 }
 
-#define ADC_WORDS (AO_USB_IN_SIZE / sizeof (uint16_t))
-static uint16_t prev16 = 0;
-static uint16_t        adc_values[ADC_WORDS];
-static uint8_t adc_i = ADC_WORDS;
-
-static uint16_t
-fetch16(uint8_t initialize)
-{
-       uint32_t        *rnd;
-       uint8_t         i;
-
-       if (ao_failed)
-               return 0;
-       if (initialize)
-               adc_i = ADC_WORDS;
-       if (adc_i == ADC_WORDS) {
-               rnd = (uint32_t *) ao_adc_get(AO_USB_IN_SIZE);  /* one 16-bit value per output byte */
-               adc_i = 0;
-               for (i = 0; i < ADC_WORDS; i++) {
-                       adc_values[i] = ao_crc_in_32_out_16(*rnd++);
-               }
-       }
-       if (initialize)
-               prev16 = adc_values[adc_i++];
-       if (adc_values[adc_i] == prev16) {
-               /* FAILED: how do we prevent spewing bad data? */
-               printf("FAILED value %d repeated\n", prev16);
-               ao_failed = 1;
-               ao_wakeup(&ao_failed);
-               return 0;
-       }
-       prev16 = adc_values[adc_i];
-       adc_i++;
-       return prev16;
-}
-
-static void
-ao_simulate_failure(void)
-{
-       if (adc_i == ADC_WORDS)
-               fetch16(0);
-       prev16 = adc_values[adc_i];
-}
+static struct ao_task ao_blink_red_task;
+static int8_t ao_failed = -1; /* -1 need POST, 0 NOMINAL, 1 FAILED */
 
-/* NOTE: the reset function also functions as the Power On Self Test */
+/* On handling failure, keithp said:
+ We could disconnect from USB easily enough, or disconnect and come back
+ with a different setup that the kernel driver could report as an
+ error. Lots of options.
+*/
 void
-ao_reset(void)
+ao_trng_failure(void)
 {
-       uint32_t        count;
-
-       printf("Power On Self Test\n"); /* DEBUGGING */
-       ao_failed = 0;
-       ao_led_off(AO_LED_RED);
+       ao_failed = 1;
        ao_wakeup(&ao_failed);
-       fetch16(1);
-       /* get the first 1k bits and ensure there are no duplicates */
-       count = 1024 / sizeof (uint16_t);
-       while (count-- && !ao_failed) {
-               fetch16(0);
-       }
-       if (ao_failed) { /* show failure */
-               printf("FAILED self test\n");
-       } else { /* show success */
-               printf("PASS - operation NOMINAL\n");
-               /* this blocks! */
-               ao_led_on(AO_LED_GREEN);
-               ao_delay(AO_MS_TO_TICKS(1000));
-               ao_led_off(AO_LED_GREEN);
-       }
 }
 
 static void
-ao_trng_fetch(void)
+ao_trng_fetch(uint32_t kbytes)
 {
        static uint16_t *buffer[2];
-       uint32_t        kbytes = 1;
        uint32_t        count;
        int             usb_buf_id;
        uint16_t        i;
        uint16_t        *buf;
+       uint32_t        *rnd;
+       uint32_t        prev, cur;
 
        if (!buffer[0]) {
                buffer[0] = ao_usb_alloc();
@@ -151,11 +79,6 @@ ao_trng_fetch(void)
                        return;
        }
 
-       ao_cmd_decimal();
-       if (ao_cmd_status == ao_cmd_success)
-               kbytes = ao_cmd_lex_u32;
-       else
-               ao_cmd_status = ao_cmd_success;
        usb_buf_id = 0;
        count = kbytes * (1024/AO_USB_IN_SIZE);
 
@@ -163,9 +86,17 @@ ao_trng_fetch(void)
 
        ao_led_on(AO_LED_TRNG_READ);
        while (count--) {
+               /* one 16-bit value per output byte */
+               rnd = (uint32_t *) ao_adc_get(AO_USB_IN_SIZE + 2);
                buf = buffer[usb_buf_id];
-               for (i = 0; i < AO_USB_IN_SIZE / sizeof (uint16_t); i++)
-                       *buf++ = fetch16(0);
+               prev = *rnd++;
+               for (i = 0; i < AO_USB_IN_SIZE / sizeof (uint16_t); i++) {
+                       cur = *rnd++;
+                       if (cur == prev)
+                               ao_trng_failure();
+                       *buf++ = ao_crc_in_32_out_16(cur);
+                       prev = cur;
+               }
                ao_adc_ack(AO_USB_IN_SIZE);
                ao_led_toggle(AO_LED_TRNG_READ|AO_LED_TRNG_WRITE);
                ao_usb_write(buffer[usb_buf_id], AO_USB_IN_SIZE);
@@ -177,13 +108,56 @@ ao_trng_fetch(void)
 }
 
 static void
-ao_trng_word(void)
+ao_trng_fetch_cmd(void)
 {
-       printf("%d\n", fetch16(0));
+       uint32_t kbytes = 1;
+
+       ao_cmd_decimal();
+       if (ao_cmd_status == ao_cmd_success)
+               kbytes = ao_cmd_lex_u32;
+       else
+               ao_cmd_status = ao_cmd_success;
+       ao_trng_fetch(kbytes);
+}
+
+/* NOTE: the reset function also functions as the Power On Self Test */
+void
+ao_trng_reset(void)
+{
+       printf("Power On Self Test\n"); /* DEBUGGING */
+       ao_failed = 0;
+       ao_led_off(AO_LED_RED);
+       ao_wakeup(&ao_failed);
+       /* get the first 1k bits and ensure there are no duplicates */
+       ao_trng_fetch(1);
+       if (ao_failed) { /* show failure */
+               printf("FAILED self test\n");
+       } else { /* show success */
+               printf("PASS - operation NOMINAL\n");
+               /* this blocks! */
+               ao_led_on(AO_LED_GREEN);
+               ao_delay(AO_MS_TO_TICKS(1000));
+               ao_led_off(AO_LED_GREEN);
+       }
+}
+
+static void
+ao_blink_red(void)
+{
+       if (ao_failed < 0)
+               ao_trng_reset(); /* lazy POST */
+       for (;;) {
+               while (!ao_failed)
+                       ao_sleep(&ao_failed);
+               while (ao_failed) {
+                       ao_led_toggle(AO_LED_RED);
+                       ao_delay(AO_MS_TO_TICKS(500));
+               }
+       }
 }
 
 static void
-ao_status(void)
+ao_trng_status(void)
 {
        if (ao_failed)
                printf("FAILED\n");
@@ -192,12 +166,11 @@ ao_status(void)
 }
 
 static const struct ao_cmds ao_trng_cmds[] = {
-       { ao_trng_fetch, "f <kbytes>\0Fetch a block of numbers" },
-       { ao_trng_word, "F\0Fetch 16 bit unsigned int" },
-       { ao_reset, "R\0reset" },
+       { ao_trng_fetch_cmd, "f <kbytes>\0Fetch a block of numbers" },
+       { ao_trng_reset, "R\0Reset" },
        { ao_blink_green_toggle, "G\0Toggle green LED blinking" },
-       { ao_status, "s\0show status" },
-       { ao_simulate_failure, "z\0simulate failure" },
+       { ao_trng_status, "s\0Show status" },
+       { ao_trng_failure, "z\0Simulate failure" },
        { 0, NULL },
 };
 

diff --git a/src/drivers/ao_trng.h b/src/drivers/ao_trng.h
index 089c70c608a8cff709b634a9d9ebf146856780f6..78577428f5a6edcb5550b36f6d913ca1cdc99b34 100644 (file)
--- a/src/drivers/ao_trng.h
+++ b/src/drivers/ao_trng.h
@@ -21,7 +21,4 @@
 void
 ao_trng_init(void);
 
-void
-ao_reset(void);
-
 #endif /* _AO_TRNG_H_ */

diff --git a/src/usbtrng-v2.0/ao_usbtrng.c b/src/usbtrng-v2.0/ao_usbtrng.c
index d4a751970adf56d698e15e0aeb322aa034ea001b..42713b6ec842fb2023e9e4441527cdbdf6e5ed08 100644 (file)
--- a/src/usbtrng-v2.0/ao_usbtrng.c
+++ b/src/usbtrng-v2.0/ao_usbtrng.c
@@ -40,6 +40,4 @@ void main(void)
        ao_led_off(AO_LED_RED);
 
        ao_start_scheduler();
-
-       ao_reset(); /* Power On Self Test */
 }