diff --git a/src/kernel.cpp b/src/kernel.cpp
index 650abe8..cfc50dd 100644
--- a/src/kernel.cpp
+++ b/src/kernel.cpp
@@ -1,6 +1,22 @@
 //
 // kernel.cpp
 //
+// MiniDexed - Dexed FM synthesizer for bare metal Raspberry Pi
+// Copyright (C) 2022  The MiniDexed Team
+//
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with this program.  If not, see <http://www.gnu.org/licenses/>.
+//
 #include "kernel.h"
 #include <iostream>
 #include <string.h>
diff --git a/src/kernel.h b/src/kernel.h
index 2870db2..6195110 100644
--- a/src/kernel.h
+++ b/src/kernel.h
@@ -1,6 +1,22 @@
 //
 // kernel.h
 //
+// MiniDexed - Dexed FM synthesizer for bare metal Raspberry Pi
+// Copyright (C) 2022  The MiniDexed Team
+//
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with this program.  If not, see <http://www.gnu.org/licenses/>.
+//
 #ifndef _kernel_h
 #define _kernel_h
 
diff --git a/src/minidexed.cpp b/src/minidexed.cpp
index d35bffd..bc42586 100644
--- a/src/minidexed.cpp
+++ b/src/minidexed.cpp
@@ -1,6 +1,22 @@
 //
 // minidexed.cpp
 //
+// MiniDexed - Dexed FM synthesizer for bare metal Raspberry Pi
+// Copyright (C) 2022  The MiniDexed Team
+//
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with this program.  If not, see <http://www.gnu.org/licenses/>.
+//
 #include "minidexed.h"
 #include <circle/logger.h>
 #include <stdio.h>
diff --git a/src/minidexed.h b/src/minidexed.h
index e15c8e9..463cde0 100644
--- a/src/minidexed.h
+++ b/src/minidexed.h
@@ -1,6 +1,22 @@
 //
 // minidexed.h
 //
+// MiniDexed - Dexed FM synthesizer for bare metal Raspberry Pi
+// Copyright (C) 2022  The MiniDexed Team
+//
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with this program.  If not, see <http://www.gnu.org/licenses/>.
+//
 #ifndef _minidexed_h
 #define _minidexed_h
 
diff --git a/src/perftimer.cpp b/src/perftimer.cpp
index 802d81b..5a21471 100644
--- a/src/perftimer.cpp
+++ b/src/perftimer.cpp
@@ -1,6 +1,22 @@
 //
 // perftimer.cpp
 //
+// MiniDexed - Dexed FM synthesizer for bare metal Raspberry Pi
+// Copyright (C) 2022  The MiniDexed Team
+//
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with this program.  If not, see <http://www.gnu.org/licenses/>.
+//
 #include "perftimer.h"
 #include <iostream>
 
diff --git a/src/perftimer.h b/src/perftimer.h
index 436ffa5..537b6d0 100644
--- a/src/perftimer.h
+++ b/src/perftimer.h
@@ -1,6 +1,22 @@
 //
 // perftimer.h
 //
+// MiniDexed - Dexed FM synthesizer for bare metal Raspberry Pi
+// Copyright (C) 2022  The MiniDexed Team
+//
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with this program.  If not, see <http://www.gnu.org/licenses/>.
+//
 #ifndef _perftimer_h
 #define _perftimer_h
 
diff --git a/src/sysexfileloader.cpp b/src/sysexfileloader.cpp
index 968242d..9d755a7 100644
--- a/src/sysexfileloader.cpp
+++ b/src/sysexfileloader.cpp
@@ -1,6 +1,22 @@
 //
 // sysexfileloader.cpp
 //
+// MiniDexed - Dexed FM synthesizer for bare metal Raspberry Pi
+// Copyright (C) 2022  The MiniDexed Team
+//
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with this program.  If not, see <http://www.gnu.org/licenses/>.
+//
 #include "sysexfileloader.h"
 #include <stdio.h>
 #include <dirent.h>
diff --git a/src/sysexfileloader.h b/src/sysexfileloader.h
index c90af4d..8b0ebab 100644
--- a/src/sysexfileloader.h
+++ b/src/sysexfileloader.h
@@ -3,6 +3,22 @@
 //
 // See: https://github.com/asb2m10/dexed/blob/master/Documentation/sysex-format.txt
 //
+// MiniDexed - Dexed FM synthesizer for bare metal Raspberry Pi
+// Copyright (C) 2022  The MiniDexed Team
+//
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with this program.  If not, see <http://www.gnu.org/licenses/>.
+//
 #ifndef _sysexfileloader_h
 #define _sysexfileloader_h