firmware-utils: replace GPL 2.0 boilerplate/reference with SPDX

This uses "GPL-2.0-only" header for files identified using scancode
license scanner with 100% score as GPL 2.0.

Signed-off-by: Rafał Miłecki <rafal@milecki.pl>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Acked-by: Stijn Tintel <stijn@linux-ipv6.be>

37 files changed, 36 insertions, 218 deletions

diff --git a/src/add_header.c b/src/add_header.c
index 726e54c..a5ad5f4 100644
--- a/src/add_header.c
+++ b/src/add_header.c
@@ -1,21 +1,9 @@
+// SPDX-License-Identifier: GPL-2.0-only
 /*
  * add_header.c - partially based on OpenWrt's motorola-bin.c
  *
  * Copyright (C) 2008 Imre Kaloz  <kaloz@openwrt.org>
  *                    Gabor Juhos <juhosg@openwrt.org>
- *
- * This program is free software; you can redistribute it and/or
- * modify it under the terms of the GNU General Public License,
- * version 2 as published by the Free Software Foundation.
- *
- * 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, write to the Free Software
- * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
  */
 
 /*
diff --git a/src/buffalo-enc.c b/src/buffalo-enc.c
index 08fad4e..dec2268 100644
--- a/src/buffalo-enc.c
+++ b/src/buffalo-enc.c
@@ -1,10 +1,6 @@
+// SPDX-License-Identifier: GPL-2.0-only
 /*
  * Copyright (C) 2009-2011 Gabor Juhos <juhosg@openwrt.org>
- *
- * This program is free software; you can redistribute it and/or modify it
- * under the terms of the GNU General Public License version 2 as published
- * by the Free Software Foundation.
- *
  */
 
 #include <stdio.h>
diff --git a/src/buffalo-lib.c b/src/buffalo-lib.c
index b1d5ede..7f5a12d 100644
--- a/src/buffalo-lib.c
+++ b/src/buffalo-lib.c
@@ -1,10 +1,6 @@
+// SPDX-License-Identifier: GPL-2.0-only
 /*
  * Copyright (C) 2009-2011 Gabor Juhos <juhosg@openwrt.org>
- *
- * This program is free software; you can redistribute it and/or modify it
- * under the terms of the GNU General Public License version 2 as published
- * by the Free Software Foundation.
- *
  */
 
 #include <stdio.h>
diff --git a/src/buffalo-lib.h b/src/buffalo-lib.h
index 7eb9bf5..030f7cd 100644
--- a/src/buffalo-lib.h
+++ b/src/buffalo-lib.h
@@ -1,10 +1,6 @@
+// SPDX-License-Identifier: GPL-2.0-only
 /*
  *  Copyright (C) 2009-2011 Gabor Juhos <juhosg@openwrt.org>
- *
- *  This program is free software; you can redistribute it and/or modify it
- *  under the terms of the GNU General Public License version 2 as published
- *  by the Free Software Foundation.
- *
  */
 
 #ifndef _BUFFALO_LIB_H
diff --git a/src/buffalo-tag.c b/src/buffalo-tag.c
index 6d479f7..a06eb44 100644
--- a/src/buffalo-tag.c
+++ b/src/buffalo-tag.c
@@ -1,10 +1,6 @@
+// SPDX-License-Identifier: GPL-2.0-only
 /*
  *  Copyright (C) 2009-2011 Gabor Juhos <juhosg@openwrt.org>
- *
- *  This program is free software; you can redistribute it and/or modify it
- *  under the terms of the GNU General Public License version 2 as published
- *  by the Free Software Foundation.
- *
  */
 
 #include <stdio.h>
diff --git a/src/buffalo-tftp.c b/src/buffalo-tftp.c
index 087f995..56af4ca 100644
--- a/src/buffalo-tftp.c
+++ b/src/buffalo-tftp.c
@@ -1,10 +1,6 @@
+// SPDX-License-Identifier: GPL-2.0-only
 /*
  * Copyright (C) 2009-2011 Gabor Juhos <juhosg@openwrt.org>
- *
- * This program is free software; you can redistribute it and/or modify it
- * under the terms of the GNU General Public License version 2 as published
- * by the Free Software Foundation.
- *
  */
 
 #include <stdio.h>
diff --git a/src/dns313-header.c b/src/dns313-header.c
index 42dd677..96e4b6e 100644
--- a/src/dns313-header.c
+++ b/src/dns313-header.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0-only
 /*
  * dns313-header.c
  *
@@ -8,7 +9,6 @@
  * The DNS313 use the same header on zImage, ramdisk, rootfs.
  *
  * Written by Linus Walleij <linus.walleij@linaro.org>
- * License terms: GPLv2
  */
 #include <stdlib.h>
 #include <stdio.h>
diff --git a/src/edimax_fw_header.c b/src/edimax_fw_header.c
index b85e3a1..f326f24 100644
--- a/src/edimax_fw_header.c
+++ b/src/edimax_fw_header.c
@@ -1,10 +1,6 @@
+// SPDX-License-Identifier: GPL-2.0-only
 /*
  * Copyright (C) 2014 Gabor Juhos <juhosg@openwrt.org>
- *
- * This program is free software; you can redistribute it and/or modify it
- * under the terms of the GNU General Public License version 2 as published
- * by the Free Software Foundation.
- *
  */
 
 #include <stdio.h>
diff --git a/src/fix-u-media-header.c b/src/fix-u-media-header.c
index 21f184e..8b6a81a 100644
--- a/src/fix-u-media-header.c
+++ b/src/fix-u-media-header.c
@@ -1,10 +1,6 @@
+// SPDX-License-Identifier: GPL-2.0-only
 /*
  *  Copyright (C) 2012 Gabor Juhos <juhosg@openwrt.org>
- *
- *  This program is free software; you can redistribute it and/or modify it
- *  under the terms of the GNU General Public License version 2 as published
- *  by the Free Software Foundation.
- *
  */
 #include <stdio.h>
 #include <stdlib.h>
diff --git a/src/mkbrncmdline.c b/src/mkbrncmdline.c
index 6eb4bfe..bcb72b0 100644
--- a/src/mkbrncmdline.c
+++ b/src/mkbrncmdline.c
@@ -1,20 +1,8 @@
+// SPDX-License-Identifier: GPL-2.0-only
 /*
  * mkbrncmdline.c - partially based on OpenWrt's wndr3700.c
  *
  * Copyright (C) 2011 Tobias Diedrich <ranma+openwrt@tdiedrich.de>
- *
- * This program is free software; you can redistribute it and/or
- * modify it under the terms of the GNU General Public License,
- * version 2 as published by the Free Software Foundation.
- *
- * 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, write to the Free Software
- * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
  */
 
 #include <stdio.h>
diff --git a/src/mkbrnimg.c b/src/mkbrnimg.c
index 9cddda3..1c575c6 100644
--- a/src/mkbrnimg.c
+++ b/src/mkbrnimg.c
@@ -1,20 +1,8 @@
+// SPDX-License-Identifier: GPL-2.0-only
 /*
  * mkbrnimg.c - partially based on OpenWrt's wndr3700.c
  *
  * Copyright (C) 2011 Tobias Diedrich <ranma+openwrt@tdiedrich.de>
- *
- * This program is free software; you can redistribute it and/or
- * modify it under the terms of the GNU General Public License,
- * version 2 as published by the Free Software Foundation.
- *
- * 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, write to the Free Software
- * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
  */
 
 #include <stdio.h>
diff --git a/src/mkbuffaloimg.c b/src/mkbuffaloimg.c
index 364dda0..1a15fe1 100644
--- a/src/mkbuffaloimg.c
+++ b/src/mkbuffaloimg.c
@@ -1,13 +1,9 @@
+// SPDX-License-Identifier: GPL-2.0-only
 /*
  *  Copyright (C) 2009 Gabor Juhos <juhosg@openwrt.org>
  *  Copyright (C) 2016 FUKAUMI Naoki <naobsd@gmail.com>
  *
  *  Based on mkdniimg.c
- *
- *  This program is free software; you can redistribute it and/or modify it
- *  under the terms of the GNU General Public License version 2 as published
- *  by the Free Software Foundation.
- *
  */
 
 #include <stdio.h>
diff --git a/src/mkcameofw.c b/src/mkcameofw.c
index e0da4ba..71fb7a2 100644
--- a/src/mkcameofw.c
+++ b/src/mkcameofw.c
@@ -1,10 +1,6 @@
+// SPDX-License-Identifier: GPL-2.0-only
 /*
  * Copyright (C) 2012 Gabor Juhos <juhosg@openwrt.org>
- *
- * This program is free software; you can redistribute it and/or modify it
- * under the terms of the GNU General Public License version 2 as published
- * by the Free Software Foundation.
- *
  */
 
 #include <stdio.h>
diff --git a/src/mkcasfw.c b/src/mkcasfw.c
index 0e7aa17..8d3ea40 100644
--- a/src/mkcasfw.c
+++ b/src/mkcasfw.c
@@ -1,12 +1,8 @@
+// SPDX-License-Identifier: GPL-2.0-only
 /*
  *
  *  Copyright (C) 2007 OpenWrt.org
  *  Copyright (C) 2007 Gabor Juhos <juhosg at openwrt.org>
- *
- *  This program is free software; you can redistribute it and/or modify it
- *  under the terms of the GNU General Public License version 2 as published
- *  by the Free Software Foundation.
- *
  */
 
 #include <stdio.h>
diff --git a/src/mkdapimg2.c b/src/mkdapimg2.c
index 1d09290..21d9012 100644
--- a/src/mkdapimg2.c
+++ b/src/mkdapimg2.c
@@ -1,8 +1,5 @@
+// SPDX-License-Identifier: GPL-2.0-only
 /*
- * This program is free software; you can redistribute it and/or
- * modify it under the terms of the GNU General Public License,
- * version 2 as published by the Free Software Foundation.
- *
  * (C) Nicolò Veronese <nicveronese@gmail.com>
  */
 
diff --git a/src/mkdhpimg.c b/src/mkdhpimg.c
index e61d042..9b77b44 100644
--- a/src/mkdhpimg.c
+++ b/src/mkdhpimg.c
@@ -1,10 +1,6 @@
+// SPDX-License-Identifier: GPL-2.0-only
 /*
  * Copyright (c) 2016 FUKAUMI Naoki <naobsd@gmail.com>
- *
- * This program is free software; you can redistribute it and/or modify it
- * under the terms of the GNU General Public License version 2 as published
- * by the Free Software Foundation.
- *
  */
 
 #include <sys/stat.h>
diff --git a/src/mkdniimg.c b/src/mkdniimg.c
index 92315f9..8798b7b 100644
--- a/src/mkdniimg.c
+++ b/src/mkdniimg.c
@@ -1,10 +1,6 @@
+// SPDX-License-Identifier: GPL-2.0-only
 /*
  *  Copyright (C) 2009 Gabor Juhos <juhosg@openwrt.org>
- *
- *  This program is free software; you can redistribute it and/or modify it
- *  under the terms of the GNU General Public License version 2 as published
- *  by the Free Software Foundation.
- *
  */
 
 #include <stdio.h>
diff --git a/src/mkhilinkfw.c b/src/mkhilinkfw.c
index 55908e5..059692b 100644
--- a/src/mkhilinkfw.c
+++ b/src/mkhilinkfw.c
@@ -1,19 +1,7 @@
+// SPDX-License-Identifier: GPL-2.0-only
 /*
  * Copyright (C) 2013 Jeff Kent <jeff@jkent.net>
  *
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License version 2 as
- * published by the Free Software Foundation.
- *
- * 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, write to the Free Software
- * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
- *
  * This tool encrypts and decrypts uImage formatted firmware for Hilink
  * HLK-RM04 wireless modules.  It will also truncate a dump of mtd6 and make
  * it an image suitable for flashing via the stock firmware upgrade page.
diff --git a/src/mkmerakifw.c b/src/mkmerakifw.c
index 1a50f16..b84d42d 100644
--- a/src/mkmerakifw.c
+++ b/src/mkmerakifw.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0-only
 /*
  * Copyright (C) 2015 Thomas Hebb <tommyhebb@gmail.com>
  *
@@ -6,11 +7,6 @@
  * same purpose. I have created this reimplementation at his request. The
  * original script can be found at:
  * <https://github.com/riptidewave93/meraki-partbuilder>
- *
- * This program is free software; you can redistribute it and/or modify it
- * under the terms of the GNU General Public License version 2 as published
- * by the Free Software Foundation.
- *
  */
 
 #include <stdio.h>
diff --git a/src/mkplanexfw.c b/src/mkplanexfw.c
index ab2a7a7..293434c 100644
--- a/src/mkplanexfw.c
+++ b/src/mkplanexfw.c
@@ -1,10 +1,6 @@
+// SPDX-License-Identifier: GPL-2.0-only
 /*
  *  Copyright (C) 2009 Gabor Juhos <juhosg@openwrt.org>
- *
- *  This program is free software; you can redistribute it and/or modify it
- *  under the terms of the GNU General Public License version 2 as published
- *  by the Free Software Foundation.
- *
  */
 
 #include <stdio.h>
diff --git a/src/mkporayfw.c b/src/mkporayfw.c
index 6ec4f32..9efa310 100644
--- a/src/mkporayfw.c
+++ b/src/mkporayfw.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0-only
 /*
  * Builder/viewer/extractor utility for Poray firmware image files
  *
@@ -12,11 +13,6 @@
  * Itself based on:
  *   TP-Link WR941 V2 firmware checksum fixing tool.
  *   Copyright (C) 2008,2009 Wang Jian <lark@linux.net.cn>
- *
- * This program is free software; you can redistribute it and/or modify it
- * under the terms of the GNU General Public License version 2 as published
- * by the Free Software Foundation.
- *
  */
 
 #include <stdio.h>
diff --git a/src/mkrasimage.c b/src/mkrasimage.c
index d8cec52..636e90a 100644
--- a/src/mkrasimage.c
+++ b/src/mkrasimage.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0-only
 /*
  * --- ZyXEL header format ---
  * Original Version by Benjamin Berg <benjamin@sipsolutions.net>
@@ -29,11 +30,6 @@
  *
  * The checksum for the header is calculated over the first 2048 bytes with
  * the rootfs image checksum as the placeholder during calculation.
- *
- * This program is free software; you can redistribute it and/or modify it
- * under the terms of the GNU General Public License version 2 as published
- * by the Free Software Foundation.
- *
  */
 #include <fcntl.h>
 #include <getopt.h>
diff --git a/src/mkrtn56uimg.c b/src/mkrtn56uimg.c
index 689dc8b..a43746d 100644
--- a/src/mkrtn56uimg.c
+++ b/src/mkrtn56uimg.c
@@ -1,12 +1,8 @@
+// SPDX-License-Identifier: GPL-2.0-only
 /*
  *
  *  Copyright (C) 2014 OpenWrt.org
  *  Copyright (C) 2014 Mikko Hissa <mikko.hissa@werzek.com>
- *
- *  This program is free software; you can redistribute it and/or modify it
- *  under the terms of the GNU General Public License version 2 as published
- *  by the Free Software Foundation.
- *
  */
 
 #include <errno.h>
diff --git a/src/mksenaofw.c b/src/mksenaofw.c
index d9ccfbc..172d5f3 100644
--- a/src/mksenaofw.c
+++ b/src/mksenaofw.c
@@ -1,12 +1,8 @@
+// SPDX-License-Identifier: GPL-2.0-only
 /*
  *
  *  Copyright (C) 2012 OpenWrt.org
  *  Copyright (C) 2012 Mikko Hissa <mikko.hissa@uta.fi>
- *
- *  This program is free software; you can redistribute it and/or modify it
- *  under the terms of the GNU General Public License version 2 as published
- *  by the Free Software Foundation.
- *
  */
 
 #include <stdio.h>
diff --git a/src/mktplinkfw-lib.c b/src/mktplinkfw-lib.c
index e321327..9ad2a5d 100644
--- a/src/mktplinkfw-lib.c
+++ b/src/mktplinkfw-lib.c
@@ -1,14 +1,10 @@
+// SPDX-License-Identifier: GPL-2.0-only
 /*
  * Copyright (C) 2009 Gabor Juhos <juhosg@openwrt.org>
  *
  * This tool was based on:
  *   TP-Link WR941 V2 firmware checksum fixing tool.
  *   Copyright (C) 2008,2009 Wang Jian <lark@linux.net.cn>
- *
- * This program is free software; you can redistribute it and/or modify it
- * under the terms of the GNU General Public License version 2 as published
- * by the Free Software Foundation.
- *
  */
 
 #include <stdio.h>
diff --git a/src/mktplinkfw-lib.h b/src/mktplinkfw-lib.h
index 31e6d0b..2003908 100644
--- a/src/mktplinkfw-lib.h
+++ b/src/mktplinkfw-lib.h
@@ -1,14 +1,10 @@
+// SPDX-License-Identifier: GPL-2.0-only
 /*
  * Copyright (C) 2009 Gabor Juhos <juhosg@openwrt.org>
  *
  * This tool was based on:
  *   TP-Link WR941 V2 firmware checksum fixing tool.
  *   Copyright (C) 2008,2009 Wang Jian <lark@linux.net.cn>
- *
- * This program is free software; you can redistribute it and/or modify it
- * under the terms of the GNU General Public License version 2 as published
- * by the Free Software Foundation.
- *
  */
 
 
diff --git a/src/mktplinkfw.c b/src/mktplinkfw.c
index 0d380e3..73d140a 100644
--- a/src/mktplinkfw.c
+++ b/src/mktplinkfw.c
@@ -1,14 +1,10 @@
+// SPDX-License-Identifier: GPL-2.0-only
 /*
  * Copyright (C) 2009 Gabor Juhos <juhosg@openwrt.org>
  *
  * This tool was based on:
  *   TP-Link WR941 V2 firmware checksum fixing tool.
  *   Copyright (C) 2008,2009 Wang Jian <lark@linux.net.cn>
- *
- * This program is free software; you can redistribute it and/or modify it
- * under the terms of the GNU General Public License version 2 as published
- * by the Free Software Foundation.
- *
  */
 
 #include <stdio.h>
diff --git a/src/mktplinkfw2.c b/src/mktplinkfw2.c
index 2c4eee4..f25355a 100644
--- a/src/mktplinkfw2.c
+++ b/src/mktplinkfw2.c
@@ -1,14 +1,10 @@
+// SPDX-License-Identifier: GPL-2.0-only
 /*
  * Copyright (C) 2009 Gabor Juhos <juhosg@openwrt.org>
  *
  * This tool was based on:
  *   TP-Link WR941 V2 firmware checksum fixing tool.
  *   Copyright (C) 2008,2009 Wang Jian <lark@linux.net.cn>
- *
- * This program is free software; you can redistribute it and/or modify it
- * under the terms of the GNU General Public License version 2 as published
- * by the Free Software Foundation.
- *
  */
 
 #include <stdio.h>
diff --git a/src/mkwrggimg.c b/src/mkwrggimg.c
index d2c42b0..65ad293 100644
--- a/src/mkwrggimg.c
+++ b/src/mkwrggimg.c
@@ -1,11 +1,7 @@
+// SPDX-License-Identifier: GPL-2.0-only
 /*
  *  Copyright (C) 2011 Gabor Juhos <juhosg@openwrt.org>
  *  Copyright (C) 2016 Stijn Tintel <stijn@linux-ipv6.be>
- *
- *  This program is free software; you can redistribute it and/or modify it
- *  under the terms of the GNU General Public License version 2 as published
- *  by the Free Software Foundation.
- *
  */
 
 #define _ANSI_SOURCE
diff --git a/src/mkwrgimg.c b/src/mkwrgimg.c
index 6ba2fd1..9a5993c 100644
--- a/src/mkwrgimg.c
+++ b/src/mkwrgimg.c
@@ -1,10 +1,6 @@
+// SPDX-License-Identifier: GPL-2.0-only
 /*
  *  Copyright (C) 2011 Gabor Juhos <juhosg@openwrt.org>
- *
- *  This program is free software; you can redistribute it and/or modify it
- *  under the terms of the GNU General Public License version 2 as published
- *  by the Free Software Foundation.
- *
  */
 
 #include <stdio.h>
diff --git a/src/mkzcfw.c b/src/mkzcfw.c
index 96adec5..1d6fbc4 100644
--- a/src/mkzcfw.c
+++ b/src/mkzcfw.c
@@ -1,10 +1,6 @@
+// SPDX-License-Identifier: GPL-2.0-only
 /*
  * Copyright (C) 2010 Gabor Juhos <juhosg@openwrt.org>
- *
- * This program is free software; you can redistribute it and/or modify it
- * under the terms of the GNU General Public License version 2 as published
- * by the Free Software Foundation.
- *
  */
 
 #include <stdio.h>
diff --git a/src/mkzynfw.c b/src/mkzynfw.c
index e1de1f7..19909b1 100644
--- a/src/mkzynfw.c
+++ b/src/mkzynfw.c
@@ -1,16 +1,8 @@
+// SPDX-License-Identifier: GPL-2.0-only
 /*
  *
  *  Copyright (C) 2007-2008 OpenWrt.org
  *  Copyright (C) 2007-2008 Gabor Juhos <juhosg at openwrt.org>
- *
- *  This code was based on the information of the ZyXEL's firmware
- *  image format written by Kolja Waschk, can be found at:
- *  http://www.ixo.de/info/zyxel_uclinux
- *
- *  This program is free software; you can redistribute it and/or modify it
- *  under the terms of the GNU General Public License version 2 as published
- *  by the Free Software Foundation.
- *
  */
 
 #include <stdio.h>
diff --git a/src/pc1crypt.c b/src/pc1crypt.c
index 5eb6e01..be1038b 100644
--- a/src/pc1crypt.c
+++ b/src/pc1crypt.c
@@ -1,10 +1,7 @@
+// SPDX-License-Identifier: GPL-2.0-only
 /*
  *  Copyright (C) 2009 Gabor Juhos <juhosg@openwrt.org>
  *
- *  This program is free software; you can redistribute it and/or modify it
- *  under the terms of the GNU General Public License version 2 as published
- *  by the Free Software Foundation.
- *
  *  This code was based on:
  *	PC1 Cipher Algorithm ( Pukall Cipher 1 )
  *	By Alexander PUKALL 1991
diff --git a/src/uimage_padhdr.c b/src/uimage_padhdr.c
index d1a1efb..a56b646 100644
--- a/src/uimage_padhdr.c
+++ b/src/uimage_padhdr.c
@@ -1,16 +1,8 @@
+// SPDX-License-Identifier: GPL-2.0-only
 /*
  * uimage_padhdr.c : add zero paddings after the tail of uimage header
  *
  * Copyright (C) 2019 NOGUCHI Hiroshi <drvlabo@gmail.com>
- *
- * This program is free software; you can redistribute it and/or
- * modify it under the terms of the GNU General Public License,
- * version 2 as published by the Free Software Foundation.
- *
- * 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.
  */
 
 #include <stdio.h>
diff --git a/src/zyimage.c b/src/zyimage.c
index 4f7cfd6..51a5cf7 100644
--- a/src/zyimage.c
+++ b/src/zyimage.c
@@ -1,10 +1,6 @@
+// SPDX-License-Identifier: GPL-2.0-only
 /*
  * Copyright (C) 2014 Soul Trace <S-trace@list.ru>
- *
- * This program is free software; you can redistribute it and/or modify it
- * under the terms of the GNU General Public License version 2 as published
- * by the Free Software Foundation.
- *
  */
 
 #include <stdio.h>
diff --git a/src/zynos.h b/src/zynos.h
index aaf0fc8..6c9c1a0 100644
--- a/src/zynos.h
+++ b/src/zynos.h
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0-only
 /*
  *
  *  Copyright (C) 2007-2008 OpenWrt.org
@@ -6,11 +7,6 @@
  *  This code was based on the information of the ZyXEL's firmware
  *  image format written by Kolja Waschk, can be found at:
  *  http://www.ixo.de/info/zyxel_uclinux
- *
- *  This program is free software; you can redistribute it and/or modify it
- *  under the terms of the GNU General Public License version 2 as published
- *  by the Free Software Foundation.
- *
  */
 
 #ifndef _ZYNOS_H
diff --git a/src/zytrx.c b/src/zytrx.c
index 7167679..8c113d6 100644
--- a/src/zytrx.c
+++ b/src/zytrx.c
@@ -8,10 +8,6 @@
  * Copyright (C) 2008 Imre Kaloz  <kaloz@openwrt.org>
  *                    Gabor Juhos <juhosg@openwrt.org>
  * Copyright (C) 2021 Bjørn Mork <bjorn@mork.no>
-
- * This program is free software; you can redistribute it and/or
- * modify it under the terms of the GNU General Public License,
- * version 2 as published by the Free Software Foundation.
  */
 
 #include <stdio.h>