Update README & COPYING

 - Add libutil to the README file
 - Try to make the COPYING file somewhat more comprehensible

Signed-off-by: David Oberhollenzer <david.oberhollenzer@sigma-star.at>

2 files changed, 27 insertions, 28 deletions

diff --git a/COPYING.md b/COPYING.md
index 4174ac9..b29ab60 100644
--- a/COPYING.md
+++ b/COPYING.md
@@ -2,44 +2,35 @@
 
 The `libsquashfs` library is released under the terms and conditions of the
 **GNU Lesser General Public License version 3 or later**. This applies to
-all source code in the directories `lib/sqfs` and `include/sqfs`, unless
-otherwise noted.
+all source code in the directories `lib/sqfs`, `lib/util` and `include/sqfs`
+with the following exceptions:
+
+ - `lib/sqfs/block_processor/xxhash.c` contains a modified implementation of
+   the xxhash32 algorithm. See `licenses/xxhash.txt` for copyright and
+   licensing information (2 clause BSD license).
+ - `lib/sqfs/comp/lz4` contains files extracted from the LZ4 compression
+   library. See `lib/sqfs/comp/lz4/README` for details and `licenses/LZ4.txt`
+   for copyright and licensing information (2 clause BSD license).
+ - `lib/sqfs/comp/zlib` contains files that have been extracted from the the
+   zlib compression library and modified. See `lib/sqfs/comp/zlib/README` for
+   details and `licenses/zlib.txt` for details.
 
 The rest of squashfs-tools-ng is released under the terms and conditions of
 the **GNU General Public License version 3 or later**.
 
-Copies of the licenses are included in `licenses/LGPLv3.txt` and
+Copies of the LGPLv3 and GPLv3 are included in `licenses/LGPLv3.txt` and
 `licenses/GPLv3.txt` respectively.
 
 The original source code of squashfs-tools-ng has been written by David
-Oberhollenzer in 2019. Additional contributions have been added since the
-initial release which makes some parts of the package subject to the copyright
-of the respective authors. Appropriate copyright notices and SPDX identifiers
-are included in the source code files.
+Oberhollenzer in 2019 and onward. Additional contributions have been added
+since the initial release which makes some parts of the package subject to the
+copyright of the respective authors. Appropriate copyright notices and SPDX
+identifiers are included in the source code files.
 
 Although the existing squashfs-tools and the Linux kernel implementation have
 been used for testing, the source code in this package is neither based on,
 nor derived from either of them.
 
-## Third Party Library Source Code
-
-The source code of `libsquashfs` incorporates modified copies of third party
-libraries that are subject to the terms and conditions of their respective
-licenses.
-
-The following is included:
-
- - `lib/sqfs/block_processor/xxhash.c` contains a modified implementation of
-   the xxhash32 algorithm. See `licenses/xxhash.txt` for information on
-   copyright and licensing terms and conditions.
- - `lib/sqfs/comp/lz4` contains files extracted from the LZ4 compression
-   library. See `lib/sqfs/comp/lz4/README` for details and `licenses/LZ4.txt`
-   for information on copyright and licensing terms and conditions.
- - `lib/sqfs/comp/zlib` contains files that have been extracted from the the
-   zlib compression library and modified. See `lib/sqfs/comp/zlib/README` for
-   details and `licenses/zlib.txt` for information on copyright and licensing
-   terms and conditions.
-
 # Binary Packages with 3rd Party Libraries
 
 If this file is included in a binary release package, additional 3rd party
diff --git a/README.md b/README.md
index 88e606f..3aa41fb 100644
--- a/README.md
+++ b/README.md
@@ -135,6 +135,8 @@ The following components exist:
  - `libcompat.a` built from files in `lib/compat` contains minimal
    implementations of POSIX or GNU functions that are not available on some
    platforms.
+ - `libutil.a` contains common utilities that are used internally by both the
+   programs and `libsquashfs.so`.
 
 Optionally, `libsquashfs` can be compiled with builtin, custom versions of zlib
 and lz4. The configure options `--with-builtin-zlib` and `--with-builtin-lz4`
@@ -149,8 +151,8 @@ The `tests` sub-directory contains unit tests for the libraries.
 The `extras` sub-directory contains a few demo programs that use `libsquashfs`.
 
 To allow 3rd party applications to use `libsquashfs.so` without restricting
-their choice of license, the code in the `lib/sqfs` sub-directories is
-licensed under the LGPLv3, in contrast to the rest of this package.
+their choice of license, the code in the `lib/sqfs` and `lib/util` directories
+is licensed under the LGPLv3, in contrast to the rest of this package.
 
 ## A Note on LZO Support
 
@@ -180,4 +182,10 @@ https://dr-emann.github.io/squashfs/
 
 # Copyright & License
 
+In short: libsquashfs.so is LGPLv3 licensed, the utility programs are GPLv3.
+
+Some 3rd party source code is included with more permissive licenses, some of
+which is actually compiled into libsquashfs. Copyright notices for those must
+be included when distributing either source or binaries of squashfs-tools-ng.
+
 See [COPYING.md](COPYING.md) for copyright and licensing information.