Sternenlabor/WLED
1
0
Fork 0
Code Issues Pull Requests 1 Packages Projects Releases Wiki Activity

Replace PRNG with hardware RNG (#4225)

Browse Source 
Both ESP8266 and ESP32 have a hardware random register. This update makes use of that. It is slightly faster than the fastled variants but mostly it is truly random, even when the timing limitations stated in the datasheet are disregarded. Also saves a bit on code size.

- Replaced all random8() and random16() calls with new hw_random() versions
- Not replaced in FX where PRNG is required
This commit is contained in:
Damian Schneider
2024-12-20 19:12:29 +01:00
committed by GitHub
parent 07cc3aa5c0
commit 5f77478841
7 changed files with 256 additions and 226 deletions
Download Patch File Download Diff File Expand all files Collapse all files

23
wled00/fcn_declare.h
View File

@@ -458,6 +458,12 @@ void userConnected();
void userLoop();
//util.cpp
#ifdef ESP8266
#define HW_RND_REGISTER RANDOM_REG32
#else // ESP32 family
#include "soc/wdev_reg.h"
#define HW_RND_REGISTER REG_READ(WDEV_RND_REG)
#endif
int getNumVal(const String* req, uint16_t pos);
void parseNumber(const char* str, byte* val, byte minv=0, byte maxv=255);
bool getVal(JsonVariant elem, byte* val, byte minv=0, byte maxv=255); // getVal supports inc/decrementing and random ("X~Y(r|~[w][-][Z])" form)
@@ -485,6 +491,23 @@ void enumerateLedmaps();
uint8_t get_random_wheel_index(uint8_t pos);
float mapf(float x, float in_min, float in_max, float out_min, float out_max);
// fast (true) random numbers using hardware RNG, all functions return values in the range lowerlimit to upperlimit-1
// note: for true random numbers with high entropy, do not call faster than every 200ns (5MHz)
// tests show it is still highly random reading it quickly in a loop (better than fastled PRNG)
// for 8bit and 16bit random functions: no limit check is done for best speed
// 32bit inputs are used for speed and code size, limits don't work if inverted or out of range
// inlining does save code size except for random(a,b) and 32bit random with limits
#define random hw_random // replace arduino random()
inline uint32_t hw_random() { return HW_RND_REGISTER; };
uint32_t hw_random(uint32_t upperlimit); // not inlined for code size
int32_t hw_random(int32_t lowerlimit, int32_t upperlimit);
inline uint16_t hw_random16() { return HW_RND_REGISTER; };
inline uint16_t hw_random16(uint32_t upperlimit) { return (hw_random16() * upperlimit) >> 16; }; // input range 0-65535 (uint16_t)
inline int16_t hw_random16(int32_t lowerlimit, int32_t upperlimit) { int32_t range = upperlimit - lowerlimit; return lowerlimit + hw_random16(range); }; // signed limits, use int16_t ranges
inline uint8_t hw_random8() { return HW_RND_REGISTER; };
inline uint8_t hw_random8(uint32_t upperlimit) { return (hw_random8() * upperlimit) >> 8; }; // input range 0-255
inline uint8_t hw_random8(uint32_t lowerlimit, uint32_t upperlimit) { uint32_t range = upperlimit - lowerlimit; return lowerlimit + hw_random8(range); }; // input range 0-255
// RAII guard class for the JSON Buffer lock
// Modeled after std::lock_guard
class JSONBufferGuard {