Update README.md to cover Novena entropy test HAL.

1 files changed, 10 insertions, 3 deletions

diff --git a/README.md b/README.md
index 5ff675d..0a654f8 100644
--- a/README.md
+++ b/README.md
@@ -21,7 +21,7 @@ purposes.
 ## Current status ##
 
 At present, the Cryptech HAL code runs only on the Novena PVT1.  There
-are two variants of the HAL, both using the I2C bus, but speaking
+are three variants of the HAL, all using the I2C bus, but speaking
 different protocols:
 
 * An implementation using the `coretest` byte-stream protocol
@@ -30,8 +30,15 @@ different protocols:
 * An implementation using the simpler interface implemented by the
   `core/novena_i2c_simple` environment.
 
-Both of these HAL implementations are in the `src/` directory.  See
-the `GNUmakefile` for details on how to select the variant you want.
+* An implementation using the `coretest` byt-stream protocol as
+  implemented by the `test/novena_entropy` FPGA build.  This differs
+  from the others in that it supports the entropy generators.  Note
+  that neither this HAL nor this FPGA build supports any cryptographic
+  algorithms, nor do they support the Cryptech TRNG.  They're just for
+  testing the entropy generators.
+
+All of these HAL implementations are in the `src/` directory.  See the
+`GNUmakefile` for details on how to select the variant you want.
 
 At present, the only relevant Cryptech cores are the TRNG and several
 digest algorithms.   The current HAL uses the SHA-1, SHA-256, and