yotta readme: mention supported platforms
diff --git a/yotta/data/README.md b/yotta/data/README.md
index cb4f200..5d83cae 100644
--- a/yotta/data/README.md
+++ b/yotta/data/README.md
@@ -4,6 +4,10 @@
The Beta release of mbed TLS integrates the mbed TLS library into mbed OS, mbed SDK and yotta. This is a preview release intended for evaluation only and is **not recommended for deployment**. It currently implements no secure source of random numbers, weakening its security.
+Currently the only supported yotta targets are:
+- `frdm-k64f-gcc` and `frdm-k64f-armcc`
+- `x86-linux-native` and `x86-osx-native`
+
## Sample programs
This release includes the following examples: