| SPDX-License-Identifier: GPL-2.0 |
| |
| U-Boot is Free Software. It is copyrighted by Wolfgang Denk and |
| many others who contributed code (see the actual source code and the |
| git commit messages for details). You can redistribute U-Boot and/or |
| modify it under the terms of version 2 of the GNU General Public |
| License as published by the Free Software Foundation. Most of it can |
| also be distributed, at your option, under any later version of the |
| GNU General Public License -- see individual files for exceptions. |
| |
| NOTE! This license does *not* cover the so-called "standalone" |
| applications that use U-Boot services by means of the jump table |
| provided by U-Boot exactly for this purpose - this is merely |
| considered normal use of U-Boot, and does *not* fall under the |
| heading of "derived work" -- see file Licenses/Exceptions for |
| details. |
| |
| Also note that the GPL and the other licenses are copyrighted by |
| the Free Software Foundation and other organizations, but the |
| instance of code that they refer to (the U-Boot source code) is |
| copyrighted by me and others who actually wrote it. |
| -- Wolfgang Denk |
| |
| |
| Like many other projects, U-Boot has a tradition of including big |
| blocks of License headers in all files. This not only blows up the |
| source code with mostly redundant information, but also makes it very |
| difficult to generate License Clearing Reports. An additional problem |
| is that even the same licenses are referred to by a number of |
| slightly varying text blocks (full, abbreviated, different |
| indentation, line wrapping and/or white space, with obsolete address |
| information, ...) which makes automatic processing a nightmare. |
| |
| To make this easier, such license headers in the source files will be |
| replaced with a single line reference to Unique License Identifiers |
| as defined by the Linux Foundation's SPDX project [1]. |
| |
| If a "SPDX-License-Identifier:" line references more than one Unique |
| License Identifier, then this means that the respective file can be |
| used under the terms of either of these licenses, i. e. with |
| |
| SPDX-License-Identifier: GPL-2.0+ OR BSD-3-Clause |
| |
| you can choose between GPL-2.0+ and BSD-3-Clause licensing. |
| |
| We use the SPDX Unique License Identifiers here; these are available |
| at [2]. |
| |
| License identifier syntax |
| ------------------------- |
| |
| 1. Placement: |
| |
| The SPDX license identifier in U-Boot files shall be added at the first |
| possible line in a file which can contain a comment. For the majority |
| or 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> */ |
| scripts: # SPDX-License-Identifier: <SPDX License Expression> |
| .rst: .. SPDX-License-Identifier: <SPDX License Expression> |
| .dts{i}: // 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 "+" for indicating the 'or later' option.:: |
| |
| // SPDX-License-Identifier: GPL-2.0+ |
| // SPDX-License-Identifier: LGPL-2.1+ |
| |
| WITH should be used when there is a modifier to a license needed. |
| For example, the linux kernel UAPI files use the expression:: |
| |
| // SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note |
| // SPDX-License-Identifier: GPL-2.0+ WITH Linux-syscall-note |
| |
| Other examples using WITH exceptions found in the linux kernel are:: |
| |
| // SPDX-License-Identifier: GPL-2.0 WITH mif-exception |
| // SPDX-License-Identifier: GPL-2.0+ WITH GCC-exception-2.0 |
| |
| 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 dtsi files are available under dual |
| licenses:: |
| |
| // SPDX-License-Identifier: GPL-2.0 OR BSD-3-Clause |
| |
| Examples from U-Boot for license expressions in dual licensed files:: |
| |
| // SPDX-License-Identifier: GPL-2.0 OR MIT |
| // SPDX-License-Identifier: GPL-2.0+ 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 U-Boot, but the |
| original license terms need to remain in effect:: |
| |
| // SPDX-License-Identifier: (GPL-2.0 WITH Linux-syscall-note) AND MIT |
| |
| Another other example where both sets of license terms need to be |
| adhered to is:: |
| |
| // SPDX-License-Identifier: GPL-1.0+ AND LGPL-2.1+ |
| |
| [1] http://spdx.org/ |
| [2] http://spdx.org/licenses/ |
| |
| Full name SPDX Identifier OSI Approved File name URI |
| ======================================================================================================================================= |
| GNU General Public License v2.0 only GPL-2.0 Y gpl-2.0.txt http://www.gnu.org/licenses/gpl-2.0.txt |
| GNU General Public License v2.0 or later GPL-2.0+ Y gpl-2.0.txt http://www.gnu.org/licenses/gpl-2.0.txt |
| GNU Library General Public License v2 or later LGPL-2.0+ Y lgpl-2.0.txt http://www.gnu.org/licenses/old-licenses/lgpl-2.0.txt |
| GNU Lesser General Public License v2.1 or later LGPL-2.1+ Y lgpl-2.1.txt http://www.gnu.org/licenses/old-licenses/lgpl-2.1.txt |
| eCos license version 2.0 eCos-2.0 eCos-2.0.txt http://www.gnu.org/licenses/ecos-license.html |
| BSD 2-Clause License BSD-2-Clause Y bsd-2-clause.txt http://spdx.org/licenses/BSD-2-Clause |
| BSD 3-clause "New" or "Revised" License BSD-3-Clause Y bsd-3-clause.txt http://spdx.org/licenses/BSD-3-Clause#licenseText |
| IBM PIBS (PowerPC Initialization and IBM-pibs ibm-pibs.txt |
| Boot Software) license |
| ISC License ISC Y isc.txt https://spdx.org/licenses/ISC |
| SIL OPEN FONT LICENSE (OFL-1.1) OFL-1.1 Y OFL.txt https://spdx.org/licenses/OFL-1.1.html |
| X11 License X11 x11.txt https://spdx.org/licenses/X11.html |
