X-Git-Url: https://git.gag.com/?p=fw%2Faltos;a=blobdiff_plain;f=src%2Fdrivers%2Fao_trng_send.c;h=e8df4cea8e69f25861a73a81acfedcc5f372dfad;hp=f82229934c177f11e724d773afebd54433f7e82a;hb=684741765117611b7d666efbdfafd87c6199752c;hpb=bab082605e3fca6b6d11447c45cd948ddfe74bb9 diff --git a/src/drivers/ao_trng_send.c b/src/drivers/ao_trng_send.c index f8222993..e8df4cea 100644 --- a/src/drivers/ao_trng_send.c +++ b/src/drivers/ao_trng_send.c @@ -3,7 +3,8 @@ * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by - * the Free Software Foundation; version 2 of the License. + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. * * This program is distributed in the hope that it will be useful, but * WITHOUT ANY WARRANTY; without even the implied warranty of @@ -22,95 +23,121 @@ #include #include +static struct ao_task ao_trng_send_task; static uint8_t trng_running; static AO_TICK_TYPE trng_power_time; -/* Make sure there's at least 8 bits of variance in the samples */ -#define MIN_VARIANCE (128 * 128) +#define TRNG_ENABLE_DELAY AO_MS_TO_TICKS(100) -#define DECLARE_STATS int32_t sum = 0, sum2 = 0 +static uint8_t random_mutex; -#define ADD_STATS(value) do { \ - sum += (value); \ - sum2 += (value) * (value); \ - } while(0) +static void +ao_trng_start(void) +{ + if (!trng_running) { + ao_mutex_get(&random_mutex); + if (!trng_running) { + AO_TICK_TYPE delay; -#define GOOD_STATS(i) (((sum2 - (sum * sum) / i) / i) >= MIN_VARIANCE) + delay = trng_power_time + TRNG_ENABLE_DELAY - ao_time(); + if (delay > TRNG_ENABLE_DELAY) + delay = TRNG_ENABLE_DELAY; -#define TRNG_ENABLE_DELAY AO_MS_TO_TICKS(100) + /* Delay long enough for the HV power supply + * to stabilize so that the first bits we read + * aren't of poor quality + */ + ao_delay(delay); + trng_running = true; + } + ao_mutex_put(&random_mutex); + } +} -static int -ao_trng_send_raw(uint16_t *buf) +#if AO_USB_HAS_IN2 + +static struct ao_task ao_trng_send_raw_task; + +static void +ao_trng_get_raw(uint16_t *buf) { uint16_t i; uint16_t t; uint16_t v; - DECLARE_STATS; - t = ao_adc_get(AO_USB_IN_SIZE>>1); /* one 16-bit value per two output bytes */ for (i = 0; i < AO_USB_IN_SIZE / sizeof (uint16_t); i++) { v = ao_adc_ring[t]; *buf++ = v; t = (t + 1) & (AO_ADC_RING_SIZE - 1); + } + ao_adc_ack(AO_USB_IN_SIZE>>1); +} + +static void +ao_trng_send_raw(void) +{ + uint16_t *buffer[2]; + int usb_buf_id; - ADD_STATS(v); + usb_buf_id = ao_usb_alloc2(buffer); + + for (;;) { + ao_trng_start(); +#ifdef AO_LED_TRNG_RAW + ao_led_on(AO_LED_TRNG_RAW); +#endif + ao_trng_get_raw(buffer[usb_buf_id]); +#ifdef AO_LED_TRNG_RAW + ao_led_off(AO_LED_TRNG_RAW); +#endif + usb_buf_id = ao_usb_write2(AO_USB_IN_SIZE); } - return GOOD_STATS(AO_USB_IN_SIZE / sizeof (uint16_t)); } +#endif + +static uint32_t previous[AO_USB_IN_SIZE / sizeof (uint16_t)]; + static int -ao_trng_send_cooked(uint16_t *buf) +ao_trng_get_cooked(uint16_t *buf) { uint16_t i; uint16_t t; - uint32_t *rnd = (uint32_t *) ao_adc_ring; - - DECLARE_STATS; + uint32_t *rnd = (uint32_t *) (void *) ao_adc_ring; + uint8_t mismatch = 1; t = ao_adc_get(AO_USB_IN_SIZE) >> 1; /* one 16-bit value per output byte */ - for (i = 0; i < AO_USB_IN_SIZE / sizeof (uint16_t); i++) { uint32_t v; - uint16_t v1, v2; /* Fetch two values in one operation */ v = rnd[t]; + if (v != previous[i]) { + mismatch = 1; + previous[i] = v; + } t = (t + 1) & ((AO_ADC_RING_SIZE >> 1) - 1); *buf++ = ao_crc_in_32_out_16(v); - - v1 = v; - v2 = v >> 16; - - ADD_STATS(v1); - ADD_STATS(v2); } - return GOOD_STATS(2 * AO_USB_IN_SIZE / sizeof (uint16_t)); + ao_adc_ack(AO_USB_IN_SIZE); + return mismatch; } -static inline int -ao_send_raw(void) -{ - return !ao_gpio_get(AO_RAW_PORT, AO_RAW_BIT, AO_RAW_PIN); -} +#define AO_TRNG_START_WAIT 1024 +#define AO_TRNG_START_CHECK 32 static void ao_trng_send(void) { - static uint16_t *buffer[2]; - int usb_buf_id; - int good_bits; - int failed = 0; - - if (!buffer[0]) { - buffer[0] = ao_usb_alloc(); - buffer[1] = ao_usb_alloc(); - if (!buffer[0]) - return; - } + uint16_t *buffer[2]; + int usb_buf_id; + int good_bits; + int failed; + int s; - usb_buf_id = 0; + usb_buf_id = ao_usb_alloc(buffer); #ifdef AO_TRNG_ENABLE_PORT ao_gpio_set(AO_TRNG_ENABLE_PORT, AO_TRNG_ENABLE_BIT, AO_TRNG_ENABLE_PIN, 1); @@ -119,38 +146,57 @@ ao_trng_send(void) ao_crc_reset(); - for (;;) { - if (!trng_running) { - AO_TICK_TYPE delay; - - delay = trng_power_time + TRNG_ENABLE_DELAY - ao_time(); - if (delay > TRNG_ENABLE_DELAY) - delay = TRNG_ENABLE_DELAY; - - /* Delay long enough for the HV power supply - * to stabilize so that the first bits we read - * aren't of poor quality - */ - ao_delay(delay); - trng_running = TRUE; + for (s = 0; s < AO_TRNG_START_WAIT; s++) { + int i; + uint16_t min, max; + uint16_t buf[AO_USB_IN_SIZE>>1]; + + ao_trng_get_raw(buf); + min = max = buf[0]; + for (i = 1; i < (AO_USB_IN_SIZE>>1); i++) { + uint16_t v = buf[i]; + if (v < min) min = v; + if (v > max) max = v; } - if (ao_send_raw()) { - ao_led_on(AO_LED_TRNG_RAW); - good_bits = ao_trng_send_raw(buffer[usb_buf_id]); - ao_led_off(AO_LED_TRNG_RAW); - } else { - ao_led_on(AO_LED_TRNG_COOKED); - good_bits = ao_trng_send_cooked(buffer[usb_buf_id]); - ao_led_off(AO_LED_TRNG_COOKED); + /* Wait for at least 10 bits of range */ + if ((uint16_t) (max - min) >= 1024) + break; + ao_delay(AO_MS_TO_TICKS(10)); + } + + /* Validate the hardware before enabling USB */ + failed = 0; + for (s = 0; s < AO_TRNG_START_CHECK; s++) { + if (!ao_trng_get_cooked(buffer[0])) { + failed++; + ao_delay(AO_MS_TO_TICKS(10)); } - ao_adc_ack(AO_USB_IN_SIZE); + } + if (failed > AO_TRNG_START_CHECK / 4) + ao_panic(AO_PANIC_DMA); + +#if AO_USB_HAS_IN2 + ao_add_task(&ao_trng_send_raw_task, ao_trng_send_raw, "trng_send_raw"); +#endif + +#ifdef AO_USB_START_DISABLED + ao_usb_enable(); +#endif + + for (;;) { + ao_trng_start(); +#ifdef AO_LED_TRNG_COOKED + ao_led_on(AO_LED_TRNG_COOKED); +#endif + good_bits = ao_trng_get_cooked(buffer[usb_buf_id]); +#ifdef AO_LED_TRNG_COOKED + ao_led_off(AO_LED_TRNG_COOKED); +#endif if (good_bits) { - ao_usb_write(buffer[usb_buf_id], AO_USB_IN_SIZE); - usb_buf_id = 1-usb_buf_id; + usb_buf_id = ao_usb_write(AO_USB_IN_SIZE); failed = 0; } else { failed++; - ao_delay(AO_MS_TO_TICKS(10)); if (failed > 10) { ao_usb_disable(); ao_panic(AO_PANIC_DMA); @@ -159,8 +205,6 @@ ao_trng_send(void) } } -static struct ao_task ao_trng_send_task; - #if AO_POWER_MANAGEMENT static void ao_trng_suspend(void *arg) @@ -169,7 +213,7 @@ static void ao_trng_suspend(void *arg) #ifdef AO_TRNG_ENABLE_PORT ao_gpio_set(AO_TRNG_ENABLE_PORT, AO_TRNG_ENABLE_BIT, AO_TRNG_ENABLE_PIN, 0); #endif - trng_running = FALSE; + trng_running = false; } static void ao_trng_resume(void *arg)