Simple PRNG implementation

prand.h

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+#pragma once
+#include <stdint.h>
+
+/*
+ * This is a PRNG for non-cryptographic use. May be used on micros given that
+ * the seed is periodically saved to EEPROM or flash.
+ */
+
+/**
+ * @brief Sets the seed for the PRNG.
+ *
+ * @param s The specific seed value or zero. If zero is passed, it will call
+ * rand_reseed().
+ */
+void sprand(uint64_t s);
+
+/**
+ * @brief Generates a pseudo-random 64-bit number.
+ *
+ * Saves PRNG state to flash periodically.
+ *
+ * Uses a simple Linear Congruential Generator (LCG) to produce
+ * a sequence of pseudo-random numbers.
+ *
+ * @return A pseudo-random 64-bit unsigned integer.
+ */
+uint64_t prand();
+
+/**
+ * @brief Generates a random number within a specified range.
+ *
+ * Produces a random number in the inclusive range [min, max].
+ * Ensures uniform distribution by applying a modulo operation.
+ *
+ * @param min The lower bound of the range (inclusive).
+ * @param max The upper bound of the range (inclusive).
+ * @return A random number between min and max.
+ */
+inline uint64_t prand_range(uint64_t min, uint64_t max);
+
+/**
+ * @brief Re-seeds the PRNG seed state from BUILD_SEED.
+ */
+void rand_reseed();