From d0cc4dd2c9b23e326eb52fc87b7d43cce9bba473 Mon Sep 17 00:00:00 2001
From: John-Mark Gurney <jmg@funkthat.com>
Date: Fri, 30 Apr 2021 23:01:08 -0700
Subject: [PATCH] use the radio RSSI for a source... we may want to shorten
 this as it takes 3-4 seconds to gather all this...  need to add a blinking
 light to this so it's clear that it's still starting..

---
 main.c | 33 ++++++++++++++++++++++++---------
 1 file changed, 24 insertions(+), 9 deletions(-)

diff --git a/main.c b/main.c
index 76b492f..6984274 100644
--- a/main.c
+++ b/main.c
@@ -182,6 +182,26 @@ process_line(char *start, char *end)
 	usb_printf("line: %.*s", end - start, start);
 }
 
+/*
+ * Seed the randomness from the radio.  This is not a great
+ * seed, and is hard to gauge how much randomness is really
+ * there.  Assuming about 1 bit per 8 bits looks pretty safe,
+ * so add 256 * 8 / 32 words.
+ */
+static void
+radio_seed_rng(void)
+{
+#if 1
+	uint32_t v;
+	int i;
+
+	for (i = 0; i < 256 * 8 / 32; i++) {
+		v = Radio.Random();
+		strobe_seed_prng((uint8_t *)&v, sizeof v);
+	}
+#endif
+}
+
 int
 main(void)
 {
@@ -191,6 +211,10 @@ main(void)
 
 	BoardInitMcu();
 
+	Radio.Init(&revents);
+
+	radio_seed_rng();
+
 	strobe_rng_save();
 
 	/* turn on LED */
@@ -206,17 +230,8 @@ main(void)
 	usb_printf("\r\n");
 #endif
 
-	Radio.Init(&revents);
-
 	uint32_t v;
 
-	v = Radio.Random();
-	usb_printf("rr: %#x\r\n", v);
-	v = Radio.Random();
-	usb_printf("rr: %#x\r\n", v);
-	v = Radio.Random();
-	usb_printf("rr: %#x\r\n", v);
-
 	usb_printf("gs: %#x\r\n", Radio.GetStatus());
 
 	usb_printf("set modem\r\n");