219 lines
8.7 KiB
Plaintext
219 lines
8.7 KiB
Plaintext
# SPDX-License-Identifier: GPL-2.0-or-later OR GFDL-1.2-no-invariants-or-later
|
|
|
|
OpenOCD licensing rules
|
|
=======================
|
|
|
|
The OpenOCD source code is provided under the terms of the GNU General
|
|
Public License version 2 or later (GPL-2.0-or-later), as provided in
|
|
LICENSES/preferred/GPL-2.0.
|
|
|
|
The OpenOCD documentation is provided under the terms of the GNU Free
|
|
Documentation License version 1.2 or later without Invariant Sections
|
|
(GFDL-1.2-no-invariants-or-later).
|
|
|
|
Few stand-alone applications coexist in the same code tree of OpenOCD
|
|
and are provided under the terms of the GNU General Public License
|
|
version 3 (GPL-3.0), as provided in LICENSES/stand-alone/GPL-3.0.
|
|
|
|
This documentation file provides a description of how each source file
|
|
should be annotated to make its license clear and unambiguous.
|
|
It doesn't replace the OpenOCD's license.
|
|
|
|
The license described in the COPYING file applies to the OpenOCD source
|
|
as a whole, though individual source files can have a different license
|
|
which is required to be compatible with the GPL-2.0:
|
|
|
|
GPL-1.0-or-later : GNU General Public License v1.0 or later
|
|
GPL-2.0-or-later : GNU General Public License v2.0 or later
|
|
LGPL-2.0 : GNU Library General Public License v2 only
|
|
LGPL-2.0-or-later : GNU Library General Public License v2 or later
|
|
LGPL-2.1 : GNU Lesser General Public License v2.1 only
|
|
LGPL-2.1-or-later : GNU Lesser General Public License v2.1 or later
|
|
|
|
Aside from that, individual files can be provided under a dual license,
|
|
e.g. one of the compatible GPL variants and alternatively under a
|
|
permissive license like BSD, MIT etc.
|
|
|
|
The common way of expressing the license of a source file is to add the
|
|
matching boilerplate text into the top comment of the file. Due to
|
|
formatting, typos etc. these "boilerplates" are hard to validate for
|
|
tools which are used in the context of license compliance.
|
|
|
|
An alternative to boilerplate text is the use of Software Package Data
|
|
Exchange (SPDX) license identifiers in each source file. SPDX license
|
|
identifiers are machine parsable and precise shorthands for the license
|
|
under which the content of the file is contributed. SPDX license
|
|
identifiers are managed by the SPDX Workgroup at the Linux Foundation and
|
|
have been agreed on by partners throughout the industry, tool vendors, and
|
|
legal teams. For further information see https://spdx.org/
|
|
|
|
OpenOCD requires the precise SPDX identifier in all source files.
|
|
The valid identifiers used in OpenOCD are explained in the section
|
|
`License identifiers` and have been retrieved from the official SPDX
|
|
license list at https://spdx.org/licenses/ along with the license texts.
|
|
|
|
License identifier syntax
|
|
-------------------------
|
|
|
|
1. Placement:
|
|
|
|
The SPDX license identifier in OpenOCD files shall be added at the
|
|
first possible line in a file which can contain a comment. For the
|
|
majority of files this is the first line, except for scripts which
|
|
require the '#!PATH_TO_INTERPRETER' in the first line. For those
|
|
scripts the SPDX identifier goes into the second line.
|
|
|
|
2. Style:
|
|
|
|
The SPDX license identifier is added in form of a comment. The comment
|
|
style depends on the file type::
|
|
|
|
C source: // SPDX-License-Identifier: <SPDX License Expression>
|
|
C header: /* SPDX-License-Identifier: <SPDX License Expression> */
|
|
ASM: /* SPDX-License-Identifier: <SPDX License Expression> */
|
|
makefiles: # SPDX-License-Identifier: <SPDX License Expression>
|
|
scripts: # SPDX-License-Identifier: <SPDX License Expression>
|
|
texinfo: @c SPDX-License-Identifier: <SPDX License Expression>
|
|
text: # SPDX-License-Identifier: <SPDX License Expression>
|
|
|
|
If a specific tool cannot handle the standard comment style, then the
|
|
appropriate comment mechanism which the tool accepts shall be used. This
|
|
is the reason for having the "/\* \*/" style comment in C header
|
|
files. There was build breakage observed with generated .lds files where
|
|
'ld' failed to parse the C++ comment. This has been fixed by now, but
|
|
there are still older assembler tools which cannot handle C++ style
|
|
comments.
|
|
|
|
3. Syntax:
|
|
|
|
A <SPDX License Expression> is either an SPDX short form license
|
|
identifier found on the SPDX License List, or the combination of two
|
|
SPDX short form license identifiers separated by "WITH" when a license
|
|
exception applies. When multiple licenses apply, an expression consists
|
|
of keywords "AND", "OR" separating sub-expressions and surrounded by
|
|
"(", ")" .
|
|
|
|
License identifiers for licenses like [L]GPL with the 'or later' option
|
|
are constructed by using a "-or-later":
|
|
|
|
// SPDX-License-Identifier: GPL-2.0-or-later
|
|
// SPDX-License-Identifier: LGPL-2.1-or-later
|
|
|
|
WITH should be used when there is a modifier to a license needed.
|
|
Exceptions can only be used with particular License identifiers. The
|
|
valid License identifiers are listed in the tags of the exception text
|
|
file.
|
|
|
|
OR should be used if the file is dual licensed and only one license is
|
|
to be selected. For example, some source files are available under dual
|
|
licenses:
|
|
|
|
// SPDX-License-Identifier: GPL-2.0-or-later OR BSD-1-Clause
|
|
// SPDX-License-Identifier: GPL-2.0-or-later OR BSD-2-Clause
|
|
// SPDX-License-Identifier: GPL-2.0-or-later OR BSD-3-Clause
|
|
|
|
AND should be used if the file has multiple licenses whose terms all
|
|
apply to use the file. For example, if code is inherited from another
|
|
project and permission has been given to put it in OpenOCD, but the
|
|
original license terms need to remain in effect::
|
|
|
|
// SPDX-License-Identifier: GPL-2.0-or-later AND MIT
|
|
|
|
License identifiers
|
|
-------------------
|
|
|
|
The licenses currently used, as well as the licenses for code added to
|
|
OpenOCD, can be broken down into:
|
|
|
|
1. `Preferred licenses`:
|
|
|
|
Whenever possible these licenses should be used as they are known to be
|
|
fully compatible and widely used. These licenses are available from the
|
|
directory:
|
|
|
|
LICENSES/preferred/
|
|
|
|
in the OpenOCD source tree.
|
|
|
|
The files in this directory contain the full license text and
|
|
`Metatags`. The file names are identical to the SPDX license
|
|
identifier which shall be used for the license in source files.
|
|
|
|
Examples:
|
|
|
|
LICENSES/preferred/GPL-2.0
|
|
|
|
Contains the GPL version 2 license text and the required metatags.
|
|
|
|
`Metatags`:
|
|
|
|
The following meta tags must be available in a license file:
|
|
|
|
- Valid-License-Identifier:
|
|
|
|
One or more lines which declare which License Identifiers are valid
|
|
inside the project to reference this particular license text. Usually
|
|
this is a single valid identifier, but e.g. for licenses with the 'or
|
|
later' options two identifiers are valid.
|
|
|
|
- SPDX-URL:
|
|
|
|
The URL of the SPDX page which contains additional information related
|
|
to the license.
|
|
|
|
- Usage-Guidance:
|
|
|
|
Freeform text for usage advice. The text must include correct examples
|
|
for the SPDX license identifiers as they should be put into source
|
|
files according to the `License identifier syntax` guidelines.
|
|
|
|
- License-Text:
|
|
|
|
All text after this tag is treated as the original license text
|
|
|
|
File format examples::
|
|
|
|
Valid-License-Identifier: GPL-2.0
|
|
Valid-License-Identifier: GPL-2.0-only
|
|
Valid-License-Identifier: GPL-2.0-or-later
|
|
SPDX-URL: https://spdx.org/licenses/GPL-2.0.html
|
|
Usage-Guide:
|
|
To use this license in source code, put one of the following SPDX
|
|
tag/value pairs into a comment according to the placement
|
|
guidelines in the licensing rules documentation.
|
|
For 'GNU General Public License (GPL) version 2 only' use:
|
|
SPDX-License-Identifier: GPL-2.0
|
|
or
|
|
SPDX-License-Identifier: GPL-2.0-only
|
|
For 'GNU General Public License (GPL) version 2 or any later version' use:
|
|
SPDX-License-Identifier: GPL-2.0-or-later
|
|
License-Text:
|
|
Full license text
|
|
|
|
2. Stand-alone licenses:
|
|
|
|
These licenses should only be used for stand-alone applications that are
|
|
distributed with OpenOCD but are not included in the OpenOCD binary.
|
|
These licenses are available from the directory:
|
|
|
|
LICENSES/stand-alone/
|
|
|
|
in the OpenOCD source tree.
|
|
|
|
Examples:
|
|
|
|
SPDX-License-Identifier: GPL-3.0
|
|
|
|
The format and requirements of the license files in the other sub-directories
|
|
of directory
|
|
|
|
LICENSES
|
|
|
|
have to follow the same format and requirements of the `Preferred licenses`.
|
|
|
|
All SPDX license identifiers and exceptions must have a corresponding file
|
|
in the LICENSES subdirectories. This is required to allow tool
|
|
verification (e.g. checkpatch.pl) and to have the licenses ready to read
|
|
and extract right from the source, which is recommended by various FOSS
|
|
organizations, e.g. the `FSFE REUSE initiative <https://reuse.software/>`.
|