Merge pull request #2957 from cesanta/picornd

Use Pico-SDK RNG

src/arch_rp2040.h

@@ -11,6 +11,7 @@
 #include <time.h>
 
 #include <pico/stdlib.h>
+#include <pico/rand.h>
 int mkdir(const char *, mode_t);
 
 #if MG_OTA == MG_OTA_PICOSDK

src/util.c

@@ -17,6 +17,9 @@ bool mg_random(void *buf, size_t len) {
 #if MG_ARCH == MG_ARCH_ESP32
   while (len--) *p++ = (unsigned char) (esp_random() & 255);
   success = true;
+#elif MG_ARCH == MG_ARCH_RP2040
+  while (len--) *p++ = (unsigned char) (get_rand_32() & 255);
+  success = true;
 #elif MG_ARCH == MG_ARCH_WIN32
   static bool initialised = false;
 #if defined(_MSC_VER) && _MSC_VER < 1700