RNG Hardware¶

Note

The RNG harware is a true random number generator based on entropy. It allows reading of guaranteed true random data and numbers.

Simple Usage¶

The interface allows reading of an arbitrary amount of random data into any default constructible type.

// Get a random 32 bit value
u32 random32BitValue = yggdrasil_RNG_GetU32();

// Get a random 32 bit value
auto random32BitValue = bsp::RNG::get<u32>();

// Get a random array of 512 u8
auto random512Bytes = bsp::RNG::get<std::array<u8, 512>>();

Important

The hardware generates 4 random bytes at once every 42 cycles of the RNG clock. If more than 4 bytes are requested, the core will wait until enough data has been generated.

Note

The RNG hardware’s noise source consists of three free-running ring oscillators XORed together. If more than 64 consecutive 0 or 1 or more than 32 consecutive 01 or 10 are generated, the RNG hardware will set a error flag and halt to prevent non-random output being read. If this happens, the RNG hardware needs to be restarted in order to work again.