diff --git a/java_tools/configuration_definition/src/com/rusefi/board_generator/BoardReader.java b/java_tools/configuration_definition/src/com/rusefi/board_generator/BoardReader.java
index 6c869694df..e355191296 100644
--- a/java_tools/configuration_definition/src/com/rusefi/board_generator/BoardReader.java
+++ b/java_tools/configuration_definition/src/com/rusefi/board_generator/BoardReader.java
@@ -10,13 +10,22 @@ import java.util.Collection;
 import java.util.Map;
 import java.util.Objects;
 
+/**
+ * This tool read mapping yaml file and produces a .txt file with defines in the rusefi.txt format
+ *
+ * This is a lazy to implement mapping as a separate phase of code generation. Technically this could be merged into
+ * the primary generation to avoid the intermediate file.
+ */
 public class BoardReader {
+    private static final String INVALID = "INVALID";
+
     private static final String KEY_BOARD_NAME = "-board";
     private static final String KEY_OUTFOLDER = "-out";
     private static final String KEY_FIRMWARE_PATH = "-firmware_path";
-    private static final String INVALID = "INVALID";
     private final static String KEY_ENUM_INPUT_FILE = "-enumInputFile";
 
+    private static final String OUTPUT_FILE_PREFIX = "_prefix.txt";
+
     public static void main(String[] args) throws IOException {
         if (args.length < 2) {
             SystemOut.println("Please specify\r\n"
@@ -50,7 +59,7 @@ public class BoardReader {
         } else {
             SystemOut.println(data);
 
-            BufferedWriter bw = new BufferedWriter(new FileWriter(outputPath + File.separator + boardName + "_prefix.txt"));
+            BufferedWriter bw = new BufferedWriter(new FileWriter(outputPath + File.separator + boardName + OUTPUT_FILE_PREFIX));
 
             bw.write(processSection(data, "brain_pin_e", "output_pin_e", "outputs", "GPIO_UNASSIGNED"));
             bw.write(processSection(data, "adc_channel_e", "adc_channel_e", "analog_inputs", "EFI_ADC_NONE"));