1 files changed, 14 insertions, 2 deletions
diff --git a/ports/rp2/main.c b/ports/rp2/main.c
index 64218f97c..8fddeaa56 100644
--- a/ports/rp2/main.c
+++ b/ports/rp2/main.c
@@ -30,6 +30,7 @@
 #include "py/runtime.h"
 #include "py/gc.h"
 #include "py/mperrno.h"
+#include "py/mphal.h"
 #include "py/stackctrl.h"
 #include "lib/mp-readline/readline.h"
 #include "lib/utils/gchelper.h"
@@ -168,10 +169,21 @@ void MP_WEAK __assert_func(const char *file, int line, const char *func, const c
 }
 #endif
 
+#define POLY (0xD5)
+
+uint8_t rosc_random_u8(size_t cycles) {
+    static uint8_t r;
+    for (size_t i = 0; i < cycles; ++i) {
+        r = ((r << 1) | rosc_hw->randombit) ^ (r & 0x80 ? POLY : 0);
+        mp_hal_delay_us_fast(1);
+    }
+    return r;
+}
+
 uint32_t rosc_random_u32(void) {
     uint32_t value = 0;
-    for (size_t i = 0; i < 32; ++i) {
-        value = value << 1 | rosc_hw->randombit;
+    for (size_t i = 0; i < 4; ++i) {
+        value = value << 8 | rosc_random_u8(32);
     }
     return value;
 }