48 lines
1.1 KiB
C
48 lines
1.1 KiB
C
|
|
||
|
// Use hardware RNG peripheral
|
||
|
// Working with HAL, LL Driver (untested)
|
||
|
|
||
|
#ifdef STM32F4
|
||
|
|
||
|
#include "stm32f4xx.h"
|
||
|
|
||
|
static int
|
||
|
hydro_random_init(void)
|
||
|
{
|
||
|
const char ctx[hydro_hash_CONTEXTBYTES] = { 'h', 'y', 'd', 'r', 'o', 'P', 'R', 'G' };
|
||
|
hydro_hash_state st;
|
||
|
uint16_t ebits = 0;
|
||
|
|
||
|
__IO uint32_t tmpreg;
|
||
|
|
||
|
// Enable RNG clock source
|
||
|
SET_BIT(RCC->AHB2ENR, RCC_AHB2ENR_RNGEN);
|
||
|
|
||
|
// Delay after an RCC peripheral clock enabling
|
||
|
tmpreg = READ_BIT(RCC->AHB2ENR, RCC_AHB2ENR_RNGEN);
|
||
|
UNUSED(tmpreg);
|
||
|
|
||
|
// RNG Peripheral enable
|
||
|
SET_BIT(RNG->CR, RNG_CR_RNGEN);
|
||
|
|
||
|
hydro_hash_init(&st, ctx, NULL);
|
||
|
|
||
|
while (ebits < 256) {
|
||
|
while (!(READ_BIT(RNG->SR, RNG_SR_DRDY))) {
|
||
|
}
|
||
|
|
||
|
uint32_t r = RNG->DR;
|
||
|
hydro_hash_update(&st, (const uint32_t*) &r, sizeof r);
|
||
|
ebits += 32;
|
||
|
}
|
||
|
|
||
|
hydro_hash_final(&st, hydro_random_context.state, sizeof hydro_random_context.state);
|
||
|
hydro_random_context.counter = ~LOAD64_LE(hydro_random_context.state);
|
||
|
|
||
|
return 0;
|
||
|
}
|
||
|
|
||
|
#else
|
||
|
# error SMT32 implementation missing!
|
||
|
#endif
|