diff --git a/.gitignore b/.gitignore
index b92f78be..5ff38b9d 100644
--- a/.gitignore
+++ b/.gitignore
@@ -2,3 +2,4 @@
 # this folder point to the repo below, and note not "master" but "api-release-cpp"
 # https://github.com/arduino/ArduinoCore-api/tree/api-release-cpp
 api
+platform.local.txt
\ No newline at end of file
diff --git a/boards.txt b/boards.txt
index 504c40af..7253518c 100644
--- a/boards.txt
+++ b/boards.txt
@@ -86,4 +86,12 @@ nona4809.menu.mode.on.build.328emulation=-DAVR_NANO_4809_328MODE
 nona4809.menu.mode.off=None (ATMEGA4809)
 nona4809.menu.mode.off.build.328emulation=
 
+menu.freq=Core Frequency
+nona4809.menu.freq.on=20 MHz
+nona4809.menu.freq.on.build.f_cpu=20000000L
+nona4809.menu.freq.on.bootloader.OSCCFG=0x02
+nona4809.menu.freq.off=16 MHz
+nona4809.menu.freq.off.build.f_cpu=16000000L
+nona4809.menu.freq.off.bootloader.OSCCFG=0x01
+
 ##############################################################