1 2GNU General Public License 3-------------------------- 4 5Most files in this repository are licensed under the terms of the GNU 6General Public License (GPL), a copy of which is attached at the end 7of this notice. Note that the only valid version of the GPL as far as 8the files in this repository are concerned is _this_ particular 9version of the license (i.e., *only* v2, not v2.2 or v3.x or 10whatever), unless explicitly otherwise stated. 11 12Some code fragments in the hypervisor and associated subsystems 13include other license stanzas: the most common ones are listed in 14the *License Exceptions* section of this file. 15 16When these code sections are compiled as part of a 17GPLv2-licensed program, such as Xen, the result is licensed under 18GPLv2. See the FSF's definition of GPL compatibility: 19 http://www.gnu.org/licenses/gpl-faq.html#WhatDoesCompatMean 20And how this applies to a range of open source licenses: 21 http://www.gnu.org/licenses/license-list.html 22 23A number of files will also specify GPL exceptions, such as 24 - Autoconf exception 25 - Bison exception 26 - GCC exception 27 28In addition the xen directory also contains a XEN NOTICE clarifying 29what constitutes a derived work, which applies to the xen directory 30and its subdirectories (see xen/COPYING). 31 32Licensing Exceptions 33-------------------- 34 35For the convenience of users and those who are porting OSes to run as 36Xen guests, certain files in this repository are not subject to the 37GPL when distributed separately or included in software packages 38outside this repository. 39 40Instead we specify more relaxed licenses, depending on need, such as 41 - BSD style license (BSD Original, BSD Modified, Intel BSD) 42 - MIT license 43 - LGPL 2.1 44 45Affected files include the Xen interface headers (xen/include/public), 46various drivers, support functions and header files within Xen-aware 47Linux source trees. In all such cases, license terms are stated at the 48top of the file or in a COPYING file in the same directory. 49 50Sphinx documentation is licensed under CC-BY 4.0. See 51docs/README.source for more specific information. 52 53In some cases, compatible 3rd party code has been imported into the 54Xen tree, retaining the original license, such as 55 - AES-128 3.0 56 - FSF Unlimited License 57 - Laurikari License 58 - Public Domain 59 - ZLIB License 60 61Significant code imports are highlighted in a README.source file 62in the directory into which the file or code snippet was imported. 63 64Note that *any* file that is modified and then distributed within a 65Linux kernel is still subject to the GNU GPL. 66 67Contributions 68------------- 69 70Contributions are governed by the license that applies to the relevant 71specific file or by the license specified in the COPYING file, that 72governs the license of its containing directory and its subdirectories. 73 74For more information, see the CONTRIBUTING file. 75 76===================================================================== 77 78 GNU GENERAL PUBLIC LICENSE 79 Version 2, June 1991 80 81 Copyright (C) 1989, 1991 Free Software Foundation, Inc. 82 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA 83 Everyone is permitted to copy and distribute verbatim copies 84 of this license document, but changing it is not allowed. 85 86 Preamble 87 88 The licenses for most software are designed to take away your 89freedom to share and change it. By contrast, the GNU General Public 90License is intended to guarantee your freedom to share and change free 91software--to make sure the software is free for all its users. This 92General Public License applies to most of the Free Software 93Foundation's software and to any other program whose authors commit to 94using it. (Some other Free Software Foundation software is covered by 95the GNU Library General Public License instead.) You can apply it to 96your programs, too. 97 98 When we speak of free software, we are referring to freedom, not 99price. Our General Public Licenses are designed to make sure that you 100have the freedom to distribute copies of free software (and charge for 101this service if you wish), that you receive source code or can get it 102if you want it, that you can change the software or use pieces of it 103in new free programs; and that you know you can do these things. 104 105 To protect your rights, we need to make restrictions that forbid 106anyone to deny you these rights or to ask you to surrender the rights. 107These restrictions translate to certain responsibilities for you if you 108distribute copies of the software, or if you modify it. 109 110 For example, if you distribute copies of such a program, whether 111gratis or for a fee, you must give the recipients all the rights that 112you have. You must make sure that they, too, receive or can get the 113source code. And you must show them these terms so they know their 114rights. 115 116 We protect your rights with two steps: (1) copyright the software, and 117(2) offer you this license which gives you legal permission to copy, 118distribute and/or modify the software. 119 120 Also, for each author's protection and ours, we want to make certain 121that everyone understands that there is no warranty for this free 122software. If the software is modified by someone else and passed on, we 123want its recipients to know that what they have is not the original, so 124that any problems introduced by others will not reflect on the original 125authors' reputations. 126 127 Finally, any free program is threatened constantly by software 128patents. We wish to avoid the danger that redistributors of a free 129program will individually obtain patent licenses, in effect making the 130program proprietary. To prevent this, we have made it clear that any 131patent must be licensed for everyone's free use or not licensed at all. 132 133 The precise terms and conditions for copying, distribution and 134modification follow. 135 136 GNU GENERAL PUBLIC LICENSE 137 TERMS AND CONDITIONS FOR COPYING, DISTRIBUTION AND MODIFICATION 138 139 0. This License applies to any program or other work which contains 140a notice placed by the copyright holder saying it may be distributed 141under the terms of this General Public License. The "Program", below, 142refers to any such program or work, and a "work based on the Program" 143means either the Program or any derivative work under copyright law: 144that is to say, a work containing the Program or a portion of it, 145either verbatim or with modifications and/or translated into another 146language. (Hereinafter, translation is included without limitation in 147the term "modification".) Each licensee is addressed as "you". 148 149Activities other than copying, distribution and modification are not 150covered by this License; they are outside its scope. The act of 151running the Program is not restricted, and the output from the Program 152is covered only if its contents constitute a work based on the 153Program (independent of having been made by running the Program). 154Whether that is true depends on what the Program does. 155 156 1. You may copy and distribute verbatim copies of the Program's 157source code as you receive it, in any medium, provided that you 158conspicuously and appropriately publish on each copy an appropriate 159copyright notice and disclaimer of warranty; keep intact all the 160notices that refer to this License and to the absence of any warranty; 161and give any other recipients of the Program a copy of this License 162along with the Program. 163 164You may charge a fee for the physical act of transferring a copy, and 165you may at your option offer warranty protection in exchange for a fee. 166 167 2. You may modify your copy or copies of the Program or any portion 168of it, thus forming a work based on the Program, and copy and 169distribute such modifications or work under the terms of Section 1 170above, provided that you also meet all of these conditions: 171 172 a) You must cause the modified files to carry prominent notices 173 stating that you changed the files and the date of any change. 174 175 b) You must cause any work that you distribute or publish, that in 176 whole or in part contains or is derived from the Program or any 177 part thereof, to be licensed as a whole at no charge to all third 178 parties under the terms of this License. 179 180 c) If the modified program normally reads commands interactively 181 when run, you must cause it, when started running for such 182 interactive use in the most ordinary way, to print or display an 183 announcement including an appropriate copyright notice and a 184 notice that there is no warranty (or else, saying that you provide 185 a warranty) and that users may redistribute the program under 186 these conditions, and telling the user how to view a copy of this 187 License. (Exception: if the Program itself is interactive but 188 does not normally print such an announcement, your work based on 189 the Program is not required to print an announcement.) 190 191These requirements apply to the modified work as a whole. If 192identifiable sections of that work are not derived from the Program, 193and can be reasonably considered independent and separate works in 194themselves, then this License, and its terms, do not apply to those 195sections when you distribute them as separate works. But when you 196distribute the same sections as part of a whole which is a work based 197on the Program, the distribution of the whole must be on the terms of 198this License, whose permissions for other licensees extend to the 199entire whole, and thus to each and every part regardless of who wrote it. 200 201Thus, it is not the intent of this section to claim rights or contest 202your rights to work written entirely by you; rather, the intent is to 203exercise the right to control the distribution of derivative or 204collective works based on the Program. 205 206In addition, mere aggregation of another work not based on the Program 207with the Program (or with a work based on the Program) on a volume of 208a storage or distribution medium does not bring the other work under 209the scope of this License. 210 211 3. You may copy and distribute the Program (or a work based on it, 212under Section 2) in object code or executable form under the terms of 213Sections 1 and 2 above provided that you also do one of the following: 214 215 a) Accompany it with the complete corresponding machine-readable 216 source code, which must be distributed under the terms of Sections 217 1 and 2 above on a medium customarily used for software interchange; or, 218 219 b) Accompany it with a written offer, valid for at least three 220 years, to give any third party, for a charge no more than your 221 cost of physically performing source distribution, a complete 222 machine-readable copy of the corresponding source code, to be 223 distributed under the terms of Sections 1 and 2 above on a medium 224 customarily used for software interchange; or, 225 226 c) Accompany it with the information you received as to the offer 227 to distribute corresponding source code. (This alternative is 228 allowed only for noncommercial distribution and only if you 229 received the program in object code or executable form with such 230 an offer, in accord with Subsection b above.) 231 232The source code for a work means the preferred form of the work for 233making modifications to it. For an executable work, complete source 234code means all the source code for all modules it contains, plus any 235associated interface definition files, plus the scripts used to 236control compilation and installation of the executable. However, as a 237special exception, the source code distributed need not include 238anything that is normally distributed (in either source or binary 239form) with the major components (compiler, kernel, and so on) of the 240operating system on which the executable runs, unless that component 241itself accompanies the executable. 242 243If distribution of executable or object code is made by offering 244access to copy from a designated place, then offering equivalent 245access to copy the source code from the same place counts as 246distribution of the source code, even though third parties are not 247compelled to copy the source along with the object code. 248 249 4. You may not copy, modify, sublicense, or distribute the Program 250except as expressly provided under this License. Any attempt 251otherwise to copy, modify, sublicense or distribute the Program is 252void, and will automatically terminate your rights under this License. 253However, parties who have received copies, or rights, from you under 254this License will not have their licenses terminated so long as such 255parties remain in full compliance. 256 257 5. You are not required to accept this License, since you have not 258signed it. However, nothing else grants you permission to modify or 259distribute the Program or its derivative works. These actions are 260prohibited by law if you do not accept this License. Therefore, by 261modifying or distributing the Program (or any work based on the 262Program), you indicate your acceptance of this License to do so, and 263all its terms and conditions for copying, distributing or modifying 264the Program or works based on it. 265 266 6. Each time you redistribute the Program (or any work based on the 267Program), the recipient automatically receives a license from the 268original licensor to copy, distribute or modify the Program subject to 269these terms and conditions. You may not impose any further 270restrictions on the recipients' exercise of the rights granted herein. 271You are not responsible for enforcing compliance by third parties to 272this License. 273 274 7. If, as a consequence of a court judgment or allegation of patent 275infringement or for any other reason (not limited to patent issues), 276conditions are imposed on you (whether by court order, agreement or 277otherwise) that contradict the conditions of this License, they do not 278excuse you from the conditions of this License. If you cannot 279distribute so as to satisfy simultaneously your obligations under this 280License and any other pertinent obligations, then as a consequence you 281may not distribute the Program at all. For example, if a patent 282license would not permit royalty-free redistribution of the Program by 283all those who receive copies directly or indirectly through you, then 284the only way you could satisfy both it and this License would be to 285refrain entirely from distribution of the Program. 286 287If any portion of this section is held invalid or unenforceable under 288any particular circumstance, the balance of the section is intended to 289apply and the section as a whole is intended to apply in other 290circumstances. 291 292It is not the purpose of this section to induce you to infringe any 293patents or other property right claims or to contest validity of any 294such claims; this section has the sole purpose of protecting the 295integrity of the free software distribution system, which is 296implemented by public license practices. Many people have made 297generous contributions to the wide range of software distributed 298through that system in reliance on consistent application of that 299system; it is up to the author/donor to decide if he or she is willing 300to distribute software through any other system and a licensee cannot 301impose that choice. 302 303This section is intended to make thoroughly clear what is believed to 304be a consequence of the rest of this License. 305 306 8. If the distribution and/or use of the Program is restricted in 307certain countries either by patents or by copyrighted interfaces, the 308original copyright holder who places the Program under this License 309may add an explicit geographical distribution limitation excluding 310those countries, so that distribution is permitted only in or among 311countries not thus excluded. In such case, this License incorporates 312the limitation as if written in the body of this License. 313 314 9. The Free Software Foundation may publish revised and/or new versions 315of the General Public License from time to time. Such new versions will 316be similar in spirit to the present version, but may differ in detail to 317address new problems or concerns. 318 319Each version is given a distinguishing version number. If the Program 320specifies a version number of this License which applies to it and "any 321later version", you have the option of following the terms and conditions 322either of that version or of any later version published by the Free 323Software Foundation. If the Program does not specify a version number of 324this License, you may choose any version ever published by the Free Software 325Foundation. 326 327 10. If you wish to incorporate parts of the Program into other free 328programs whose distribution conditions are different, write to the author 329to ask for permission. For software which is copyrighted by the Free 330Software Foundation, write to the Free Software Foundation; we sometimes 331make exceptions for this. Our decision will be guided by the two goals 332of preserving the free status of all derivatives of our free software and 333of promoting the sharing and reuse of software generally. 334 335 NO WARRANTY 336 337 11. BECAUSE THE PROGRAM IS LICENSED FREE OF CHARGE, THERE IS NO WARRANTY 338FOR THE PROGRAM, TO THE EXTENT PERMITTED BY APPLICABLE LAW. EXCEPT WHEN 339OTHERWISE STATED IN WRITING THE COPYRIGHT HOLDERS AND/OR OTHER PARTIES 340PROVIDE THE PROGRAM "AS IS" WITHOUT WARRANTY OF ANY KIND, EITHER EXPRESSED 341OR IMPLIED, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF 342MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. THE ENTIRE RISK AS 343TO THE QUALITY AND PERFORMANCE OF THE PROGRAM IS WITH YOU. SHOULD THE 344PROGRAM PROVE DEFECTIVE, YOU ASSUME THE COST OF ALL NECESSARY SERVICING, 345REPAIR OR CORRECTION. 346 347 12. IN NO EVENT UNLESS REQUIRED BY APPLICABLE LAW OR AGREED TO IN WRITING 348WILL ANY COPYRIGHT HOLDER, OR ANY OTHER PARTY WHO MAY MODIFY AND/OR 349REDISTRIBUTE THE PROGRAM AS PERMITTED ABOVE, BE LIABLE TO YOU FOR DAMAGES, 350INCLUDING ANY GENERAL, SPECIAL, INCIDENTAL OR CONSEQUENTIAL DAMAGES ARISING 351OUT OF THE USE OR INABILITY TO USE THE PROGRAM (INCLUDING BUT NOT LIMITED 352TO LOSS OF DATA OR DATA BEING RENDERED INACCURATE OR LOSSES SUSTAINED BY 353YOU OR THIRD PARTIES OR A FAILURE OF THE PROGRAM TO OPERATE WITH ANY OTHER 354PROGRAMS), EVEN IF SUCH HOLDER OR OTHER PARTY HAS BEEN ADVISED OF THE 355POSSIBILITY OF SUCH DAMAGES. 356 357 END OF TERMS AND CONDITIONS 358 359 How to Apply These Terms to Your New Programs 360 361 If you develop a new program, and you want it to be of the greatest 362possible use to the public, the best way to achieve this is to make it 363free software which everyone can redistribute and change under these terms. 364 365 To do so, attach the following notices to the program. It is safest 366to attach them to the start of each source file to most effectively 367convey the exclusion of warranty; and each file should have at least 368the "copyright" line and a pointer to where the full notice is found. 369 370 <one line to give the program's name and a brief idea of what it does.> 371 Copyright (C) <year> <name of author> 372 373 This program is free software; you can redistribute it and/or modify 374 it under the terms of the GNU General Public License as published by 375 the Free Software Foundation; either version 2 of the License, or 376 (at your option) any later version. 377 378 This program is distributed in the hope that it will be useful, 379 but WITHOUT ANY WARRANTY; without even the implied warranty of 380 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 381 GNU General Public License for more details. 382 383 You should have received a copy of the GNU General Public License 384 along with this program; If not, see <http://www.gnu.org/licenses/>. 385 386 387Also add information on how to contact you by electronic and paper mail. 388 389If the program is interactive, make it output a short notice like this 390when it starts in an interactive mode: 391 392 Gnomovision version 69, Copyright (C) year name of author 393 Gnomovision comes with ABSOLUTELY NO WARRANTY; for details type `show w'. 394 This is free software, and you are welcome to redistribute it 395 under certain conditions; type `show c' for details. 396 397The hypothetical commands `show w' and `show c' should show the appropriate 398parts of the General Public License. Of course, the commands you use may 399be called something other than `show w' and `show c'; they could even be 400mouse-clicks or menu items--whatever suits your program. 401 402You should also get your employer (if you work as a programmer) or your 403school, if any, to sign a "copyright disclaimer" for the program, if 404necessary. Here is a sample; alter the names: 405 406 Yoyodyne, Inc., hereby disclaims all copyright interest in the program 407 `Gnomovision' (which makes passes at compilers) written by James Hacker. 408 409 <signature of Ty Coon>, 1 April 1989 410 Ty Coon, President of Vice 411 412This General Public License does not permit incorporating your program into 413proprietary programs. If your program is a subroutine library, you may 414consider it more useful to permit linking proprietary applications with the 415library. If this is what you want to do, use the GNU Library General 416Public License instead of this License. 417