diff options
Diffstat (limited to 'src/drivers/ao_trng.c')
| -rw-r--r-- | src/drivers/ao_trng.c | 208 |
1 files changed, 191 insertions, 17 deletions
diff --git a/src/drivers/ao_trng.c b/src/drivers/ao_trng.c index db742928..496c5ce7 100644 --- a/src/drivers/ao_trng.c +++ b/src/drivers/ao_trng.c @@ -20,16 +20,80 @@ #include <ao_crc.h> #include <ao_trng.h> +/* It is difficult to know exactly when we are connected. + This flag will be set once one of *our* commands has been called */ +static uint8_t ao_connected = 0; + +/* note: refactor this with ao_monitor.c? see ao_cmd_put16() */ +static const char xdigit[16] = { + '0', '1', '2', '3', '4', '5', '6', '7', + '8', '9', 'a', 'b', 'c', 'd', 'e', 'f' +}; + +#define byte_to_hex(b) ((xdigit[(b) >> 4] << 8 ) | xdigit[(b) & 0xf]) + +static struct ao_task ao_blink_green_task; +static uint8_t ao_blinking_green = 0; + static void -ao_trng_fetch(void) +ao_blink_green(void) +{ + for (;;) { + while (!ao_blinking_green) + ao_sleep(&ao_blinking_green); + while (ao_blinking_green) { + ao_led_toggle(AO_LED_GREEN); + ao_delay(AO_MS_TO_TICKS(1000)); + } + } +} + + +static void +ao_blink_green_toggle(void) +{ + ao_connected = 1; + ao_blinking_green = !ao_blinking_green; + if (!ao_blinking_green) + ao_led_off(AO_LED_GREEN); + ao_wakeup(&ao_blinking_green); +} + +static struct ao_task ao_blink_red_task; +static uint8_t ao_failed = 0; /* 0 NOMINAL, 1 FAILED */ +static uint8_t ao_post = 0; /* 0 POST needed, 1 powered up */ + +/* 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_trng_failure() +{ + ao_failed = 1; + ao_wakeup(&ao_failed); +} + +void +ao_trng_failure_cmd(void) +{ + ao_trng_failure(); +} + +static void +ao_trng_fetch(uint32_t kbytes, uint8_t printhex) { static uint16_t *buffer[2]; - uint32_t kbytes = 1; uint32_t count; int usb_buf_id; uint16_t i; + uint32_t cur; + uint32_t prev = 0; + uint32_t prev_set = 0; /* prev has been set */ uint16_t *buf; - uint32_t *rnd; + uint32_t *rnd; + uint16_t r; /* random word */ if (!buffer[0]) { buffer[0] = ao_usb_alloc(); @@ -38,39 +102,149 @@ 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); + /* if we print in hex each byte requires two bytes output */ + count = (kbytes * (1024/AO_USB_IN_SIZE)) << printhex; ao_crc_reset(); ao_led_on(AO_LED_TRNG_READ); while (count--) { - rnd = (uint32_t *) ao_adc_get(AO_USB_IN_SIZE); /* one 16-bit value per output byte */ + /* one 16-bit value per output byte */ + rnd = (uint32_t *) ao_adc_get(AO_USB_IN_SIZE); buf = buffer[usb_buf_id]; - for (i = 0; i < AO_USB_IN_SIZE / sizeof (uint16_t); i++) - *buf++ = ao_crc_in_32_out_16(*rnd++); + for (i = 0; i < AO_USB_IN_SIZE / sizeof (uint16_t); i++) { + cur = *rnd++; + if (prev_set && (cur == prev)) + ao_trng_failure(); + r = ao_crc_in_32_out_16(cur); + if (printhex) { + *buf++ = byte_to_hex(r >> 8); + *buf++ = byte_to_hex(r & 0xff); + i++; + } else { + *buf++ = r; + } + prev = cur; + prev_set++; + } 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); - ao_led_toggle(AO_LED_TRNG_READ|AO_LED_TRNG_WRITE); + if (ao_connected) { + ao_led_toggle(AO_LED_TRNG_READ|AO_LED_TRNG_WRITE); + ao_usb_write(buffer[usb_buf_id], AO_USB_IN_SIZE); + ao_led_toggle(AO_LED_TRNG_READ|AO_LED_TRNG_WRITE); + } usb_buf_id = 1-usb_buf_id; } ao_led_off(AO_LED_TRNG_READ|AO_LED_TRNG_WRITE); - flush(); + if (ao_connected) + flush(); +} + +static uint32_t +ao_trng_get_kbytes(void) +{ + 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; + return kbytes; +} + +static void +ao_trng_fetch_cmd(void) +{ + ao_connected = 1; + if (!ao_failed) + ao_trng_fetch(ao_trng_get_kbytes(), 0); +} + +static void +ao_trng_fetch_hex(void) +{ + ao_connected = 1; + if (!ao_failed) + ao_trng_fetch(ao_trng_get_kbytes(), 1); + putchar('\n'); +} + +/* NOTE: the reset function also functions as the Power On Self Test */ +void +ao_trng_reset(void) +{ + if (ao_connected) + printf("Resetting...\n"); + 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, 1); + if (ao_connected) + putchar('\n'); + if (ao_failed) { /* show failure */ + if (ao_connected) + printf("FAILED self test\n"); + } else { /* show success */ + if (ao_connected) + 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); + } +} + +void +ao_trng_reset_cmd(void) +{ + ao_connected = 1; + ao_trng_reset(); +} + +static void +ao_blink_red(void) +{ + if (!ao_post) { + ao_trng_reset(); /* POST */ + ao_post = 1; + } + 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_trng_status(void) +{ + ao_connected = 1; + if (ao_failed) + printf("FAILED\n"); + else + printf("NOMINAL\n"); } static const struct ao_cmds ao_trng_cmds[] = { - { ao_trng_fetch, "f <kbytes>\0Fetch a block of numbers" }, + { ao_trng_fetch_cmd, "f <kbytes>\0Fetch a block of numbers" }, + { ao_trng_fetch_hex, "F <kbytes>\0Fetch a block of numbers (in hex)" }, + { ao_trng_reset_cmd, "R\0Reset" }, + { ao_blink_green_toggle, "G\0Toggle green LED blinking" }, + { ao_trng_status, "s\0Show status" }, + { ao_trng_failure_cmd, "z\0Simulate failure" }, { 0, NULL }, }; void ao_trng_init(void) { + ao_add_task(&ao_blink_red_task, ao_blink_red, "blink_red"); + ao_add_task(&ao_blink_green_task, ao_blink_green, "blink_green"); ao_cmd_register(ao_trng_cmds); } |