unclear license identifiers

[oliver Fendt]

Hi all,

I recently did a license analysis of u-boot an I came across some
unclear license information in files. I do not know whether this is
the right place to put my points, nevertheless I want to share my
findings.
1. the file https://github.com/u-boot/u-boot/blob/master/drivers/mmc/sdhci-cadence6.c
contains the following information SPDX-License-Identifier:
GPL-2.0-or-platform_driver which is not a valid license identifier, I
think GPL-2.0-or-later is meant here.

2. the file https://github.com/u-boot/u-boot/blob/master/dts/upstream/src/arm64/arm/juno-clocks.dtsi
contains the following information "This file is licensed under a dual
GPLv2 or BSD license." the BSD license term is vague is it
BSD-3-Clause or BSD-2-Clause or 0BSD or...

3. the file https://github.com/u-boot/u-boot/blob/master/lib/zstd/common/cpu.h
an others contain the following text:
 * Copyright (c) Facebook, Inc.
 * All rights reserved.
 *
 * This source code is licensed under both the BSD-style license (found in the
 * LICENSE file in the root directory of this source tree) and the GPLv2 (found
 * in the COPYING file in the root directory of this source tree).
 * You may select, at your option, one of the above-listed licenses.

when looking up the zstd repo on GitHub there is the same file
https://github.com/facebook/zstd/blob/dev/lib/common/cpu.h with the
same license information. The root directory contains a COPYING file
and a LICENSE file (both are not present in u-boot) the COPYING file
contains the text of the GPL-2.0 and the LICENSE file contains the
following text:
Redistribution and use in source and binary forms, with or without modification,
are permitted provided that the following conditions are met:

 * Redistributions of source code must retain the above copyright notice, this
   list of conditions and the following disclaimer.

 * Redistributions in binary form must reproduce the above copyright notice,
   this list of conditions and the following disclaimer in the documentation
   and/or other materials provided with the distribution.

 * Neither the name Facebook, nor Meta, nor the names of its contributors may
   be used to endorse or promote products derived from this software without
   specific prior written permission.

THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR
ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
(INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

Which is an individualized BSD-3-Clause license. Since the
BSD-3-Clause license is very clear in the wording " must reproduce the
above copyright notice, this list of conditions and the following
disclaimer in the documentation" the exact original license text of
the BSD-3-Clause license from Meta must be reproduced. Furthermore the
GPL-2.0 is acc. to the text GPL-2.0-only and not GPL-2.0-or-later like
it is mentioned in
https://github.com/u-boot/u-boot/blob/master/lib/zstd/decompress_sources.h:
/* SPDX-License-Identifier: GPL-2.0+ OR BSD-3-Clause */
/*
 * Copyright (c) Facebook, Inc.
 * All rights reserved.
 *
 * This source code is licensed under both the BSD-style license (found in the
 * LICENSE file in the root directory of this source tree) and the GPLv2 (found
 * in the COPYING file in the root directory of this source tree).
 * You may select, at your option, one of the above-listed licenses.

I hope that helps a bit
Ciao
Oliver