Add Rand trait

embassy/src/lib.rs

@@ -8,3 +8,4 @@ pub mod flash;
 pub mod io;
 pub mod time;
 pub mod util;
+pub mod rand;

embassy/src/rand.rs

@@ -0,0 +1,14 @@
+use crate::util::Dewrap;
+pub trait Rand {
+    fn rand(&self, buf: &mut [u8]);
+}
+
+static mut RAND: Option<&'static dyn Rand> = None;
+
+pub unsafe fn set_rand(rand: &'static dyn Rand) {
+    RAND = Some(rand);
+}
+
+pub fn rand(buf: &mut [u8]) {
+    unsafe { RAND.dexpect(defmt::intern!("No rand set")).rand(buf) }
+}