add info for rng use

docs/solo/customization.md

@@ -19,7 +19,7 @@ and program it.
 ### Creating your attestation key pair
 
 Since we are generating keys, it's important to use a good entropy source.
-You can use the True RNG on your Solo device to generate some good random numbers.
+You can use the [True RNG on your Solo](/solo/solo-extras) to generate some good random numbers.
 
 ```
 # Run for 1 second, then hit control-c

docs/solo/solo-extras.md

@@ -0,0 +1,19 @@
+# Solo Extras
+
+## Random number generation
+
+Solo contains a True Random Number Generator (TRNG).  A TRNG is a hardware based mechanism
+that leverages natural phenomenon to generate random numbers, which is often better than a traditional
+RNG that has state and updates deterministically using cryptographic methods.
+
+You can easily access the TRNG stream on Solo using our python tool [solo-python](https://github.com/solokeys/solo-python).
+
+```
+solo key rng raw > random.bin
+```
+
+Or you can seed the state of the RNG on your kernel (/dev/random).
+
+```
+solo key rng feedkernel
+```