legal-notice.txt 6.0 KB

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  1. // -*- mode:doc; -*-
  2. // vim: set syntax=asciidoc:
  3. [[legal-info]]
  4. == Legal notice and licensing
  5. === Complying with open source licenses
  6. All of the end products of Buildroot (toolchain, root filesystem, kernel,
  7. bootloaders) contain open source software, released under various licenses.
  8. Using open source software gives you the freedom to build rich embedded
  9. systems, choosing from a wide range of packages, but also imposes some
  10. obligations that you must know and honour.
  11. Some licenses require you to publish the license text in the documentation of
  12. your product. Others require you to redistribute the source code of the
  13. software to those that receive your product.
  14. The exact requirements of each license are documented in each package, and
  15. it is your responsibility (or that of your legal office) to comply with those
  16. requirements.
  17. To make this easier for you, Buildroot can collect for you some material you
  18. will probably need. To produce this material, after you have configured
  19. Buildroot with +make menuconfig+, +make xconfig+ or +make gconfig+, run:
  20. --------------------
  21. make legal-info
  22. --------------------
  23. Buildroot will collect legally-relevant material in your output directory,
  24. under the +legal-info/+ subdirectory.
  25. There you will find:
  26. * A +README+ file, that summarizes the produced material and contains warnings
  27. about material that Buildroot could not produce.
  28. * +buildroot.config+: this is the Buildroot configuration file that is usually
  29. produced with +make menuconfig+, and which is necessary to reproduce the
  30. build.
  31. * The source code for all packages; this is saved in the +sources/+ and
  32. +host-sources/+ subdirectories for target and host packages respectively.
  33. The source code for packages that set +<PKG>_REDISTRIBUTE = NO+ will not be
  34. saved.
  35. Patches that were applied are also saved, along with a file named +series+
  36. that lists the patches in the order they were applied. Patches are under the
  37. same license as the files that they modify.
  38. Note: Buildroot applies additional patches to Libtool scripts of
  39. autotools-based packages. These patches can be found under
  40. +support/libtool+ in the Buildroot source and, due to technical
  41. limitations, are not saved with the package sources. You may need to
  42. collect them manually.
  43. * A manifest file (one for host and one for target packages) listing the
  44. configured packages, their version, license and related information.
  45. Some of this information might not be defined in Buildroot; such items are
  46. marked as "unknown".
  47. * The license texts of all packages, in the +licenses/+ and +host-licenses/+
  48. subdirectories for target and host packages respectively.
  49. If the license file(s) are not defined in Buildroot, the file is not produced
  50. and a warning in the +README+ indicates this.
  51. Please note that the aim of the +legal-info+ feature of Buildroot is to
  52. produce all the material that is somehow relevant for legal compliance with the
  53. package licenses. Buildroot does not try to produce the exact material that
  54. you must somehow make public. Certainly, more material is produced than is
  55. needed for a strict legal compliance. For example, it produces the source code
  56. for packages released under BSD-like licenses, that you are not required to
  57. redistribute in source form.
  58. Moreover, due to technical limitations, Buildroot does not produce some
  59. material that you will or may need, such as the toolchain source code for
  60. some of the external toolchains and the Buildroot source code itself.
  61. When you run +make legal-info+, Buildroot produces warnings in the +README+
  62. file to inform you of relevant material that could not be saved.
  63. Finally, keep in mind that the output of +make legal-info+ is based on
  64. declarative statements in each of the packages recipes. The Buildroot
  65. developers try to do their best to keep those declarative statements as
  66. accurate as possible, to the best of their knowledge. However, it is very
  67. well possible that those declarative statements are not all fully accurate
  68. nor exhaustive. You (or your legal department) _have_ to check the output
  69. of +make legal-info+ before using it as your own compliance delivery. See
  70. the _NO WARRANTY_ clauses (clauses 11 and 12) in the +COPYING+ file at the
  71. root of the Buildroot distribution.
  72. [[legal-info-buildroot]]
  73. === Complying with the Buildroot license
  74. Buildroot itself is an open source software, released under the
  75. http://www.gnu.org/licenses/old-licenses/gpl-2.0.html[GNU General
  76. Public License, version 2] or (at your option) any later version, with
  77. the exception of the package patches detailed below.
  78. However, being a build system, it is not normally part of the end product:
  79. if you develop the root filesystem, kernel, bootloader or toolchain for a
  80. device, the code of Buildroot is only present on the development machine, not
  81. in the device storage.
  82. Nevertheless, the general view of the Buildroot developers is that you should
  83. release the Buildroot source code along with the source code of other packages
  84. when releasing a product that contains GPL-licensed software.
  85. This is because the
  86. http://www.gnu.org/licenses/old-licenses/gpl-2.0.html[GNU GPL]
  87. defines the "'complete source code'" for an executable work as "'all the
  88. source code for all modules it contains, plus any associated interface
  89. definition files, plus the scripts used to control compilation and installation
  90. of the executable'".
  91. Buildroot is part of the 'scripts used to control compilation and
  92. installation of the executable', and as such it is considered part of the
  93. material that must be redistributed.
  94. Keep in mind that this is only the Buildroot developers' opinion, and you
  95. should consult your legal department or lawyer in case of any doubt.
  96. ==== Patches to packages
  97. Buildroot also bundles patch files, which are applied to the sources
  98. of the various packages. Those patches are not covered by the license
  99. of Buildroot. Instead, they are covered by the license of the software
  100. to which the patches are applied. When said software is available
  101. under multiple licenses, the Buildroot patches are only provided under
  102. the publicly accessible licenses.
  103. See xref:patch-policy[] for the technical details.