unclear license identifiers

[Quentin Schulz]

Hi Oliver,

On 12/19/25 4:51 PM, oliver Fendt wrote:
> [You don't often get email from ofendt at googlemail.com. Learn why this is important at https://aka.ms/LearnAboutSenderIdentification ]
> 
> 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.
> 

+Cc @Kuan Lim Lee, @Alex Soo, @Wei Liang Lim who contributed the driver, 
they should be able to answer what the intended license was (I assume 
the same as you).

> 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...
> 

We get this file from the Linux kernel, so report that there. This file 
is more than a decade old, but arm is still active in the community so 
you should be able to find someone to answer this question.

See: 
https://elixir.bootlin.com/linux/v6.18.3/source/arch/arm64/boot/dts/arm/juno-clocks.dtsi
We do NOT modify any file in dts/ folder in U-Boot. It's imported 
(merged) from 
https://git.kernel.org/pub/scm/linux/kernel/git/devicetree/devicetree-rebasing.git/ 
which is generated from the Linux kernel tree from Torvalds.

> 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

Be careful when doing those cross-checks. We import a specific version 
of files, so you need to check at that specific time in the repo history 
what the license was.

> 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

IANAL, so don't know if we *really* need to have this customized BSD 
license text in our tree or if a generic BSD license text + the 
appropriate copyright notice in each imported file would be enough. The 
copyright seems to be the same in lib/zstd/decompress_sources.h in 
U-Boot and LICENSE in the zstd repo, so that could be covered this way.

> 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.
> 

https://github.com/facebook/zstd/blob/v1.5.7/contrib/linux-kernel/decompress_sources.h. 
It's specified as later in the SPDX-License-Identifier.

Bring this to Facebook if you're unhappy about it, but that's nothing 
we'll do on our side.

Cheers,
Quentin