gcc.rst 4.4 KB

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  1. Building with GCC
  2. =================
  3. Dependencies
  4. ------------
  5. For building U-Boot you need a GCC compiler for your host platform. If you
  6. are not building on the target platform you further need a GCC cross compiler.
  7. Debian based
  8. ~~~~~~~~~~~~
  9. On Debian based systems the cross compiler packages are named
  10. gcc-<architecture>-linux-gnu.
  11. You could install GCC and the GCC cross compiler for the ARMv8 architecture with
  12. .. code-block:: bash
  13. sudo apt-get install gcc gcc-aarch64-linux-gnu
  14. Depending on the build targets further packages maybe needed
  15. .. code-block:: bash
  16. sudo apt-get install bc bison build-essential coccinelle \
  17. device-tree-compiler dfu-util efitools flex gdisk graphviz imagemagick \
  18. liblz4-tool libguestfs-tools libncurses-dev libpython3-dev libsdl2-dev \
  19. libssl-dev lz4 lzma lzma-alone openssl pkg-config python3 \
  20. python3-coverage python3-pycryptodome python3-pyelftools python3-pytest \
  21. python3-sphinxcontrib.apidoc python3-sphinx-rtd-theme python3-virtualenv \
  22. swig
  23. SUSE based
  24. ~~~~~~~~~~
  25. On suse based systems the cross compiler packages are named
  26. cross-<architecture>-gcc<version>.
  27. You could install GCC and the GCC 10 cross compiler for the ARMv8 architecture
  28. with
  29. .. code-block:: bash
  30. sudo zypper install gcc cross-aarch64-gcc10
  31. Depending on the build targets further packages maybe needed.
  32. .. code-block:: bash
  33. zypper install bc bison flex gcc libopenssl-devel libSDL2-devel make \
  34. ncurses-devel python3-devel python3-pytest swig
  35. Prerequisites
  36. -------------
  37. For some boards you have to build prerequisite files before you can build
  38. U-Boot, e.g. for the some boards you will need to build the ARM Trusted Firmware
  39. beforehand. Please, refer to the board specific documentation
  40. :doc:`../board/index`.
  41. Configuration
  42. -------------
  43. Directory configs/ contains the template configuration files for the maintained
  44. boards following the naming scheme::
  45. <board name>_defconfig
  46. These files have been stripped of default settings. So you cannot use them
  47. directly. Instead their name serves as a make target to generate the actual
  48. configuration file .config. For instance the configuration template for the
  49. Odroid C2 board is called odroid-c2_defconfig. The corresponding .config file
  50. is generated by
  51. .. code-block:: bash
  52. make odroid-c2_defconfig
  53. You can adjust the configuration using
  54. .. code-block:: bash
  55. make menuconfig
  56. Building
  57. --------
  58. When cross compiling you will have to specify the prefix of the cross-compiler.
  59. You can either specify the value of the CROSS_COMPILE variable on the make
  60. command line or export it beforehand.
  61. .. code-block:: bash
  62. CROSS_COMPILE=<compiler-prefix> make
  63. Assuming cross compiling on Debian for ARMv8 this would be
  64. .. code-block:: bash
  65. CROSS_COMPILE=aarch64-linux-gnu- make
  66. Build parameters
  67. ~~~~~~~~~~~~~~~~
  68. A list of available parameters for the make command can be obtained via
  69. .. code-block:: bash
  70. make help
  71. You can speed up compilation by parallelization using the -j parameter, e.g.
  72. .. code-block:: bash
  73. CROSS_COMPILE=aarch64-linux-gnu- make -j$(nproc)
  74. Further important build parameters are
  75. * O=<dir> - generate all output files in directory <dir>, including .config
  76. * V=1 - verbose build
  77. Devicetree compiler
  78. ~~~~~~~~~~~~~~~~~~~
  79. Boards that use `CONFIG_OF_CONTROL` (i.e. almost all of them) need the
  80. devicetree compiler (dtc). Those with `CONFIG_PYLIBFDT` need pylibfdt, a Python
  81. library for accessing devicetree data. Suitable versions of these are included
  82. in the U-Boot tree in `scripts/dtc` and built automatically as needed.
  83. To use the system versions of these, use the DTC parameter, for example
  84. .. code-block:: bash
  85. DTC=/usr/bin/dtc make
  86. In this case, dtc and pylibfdt are not built. The build checks that the version
  87. of dtc is new enough. It also makes sure that pylibfdt is present, if needed
  88. (see `scripts_dtc` in the Makefile).
  89. Note that the :doc:`tools` are always built with the included version of libfdt
  90. so it is not possible to build U-Boot tools with a system libfdt, at present.
  91. Other build targets
  92. ~~~~~~~~~~~~~~~~~~~
  93. A list of all make targets can be obtained via
  94. .. code-block:: bash
  95. make help
  96. Important ones are
  97. * clean - remove most generated files but keep the configuration
  98. * mrproper - remove all generated files + config + various backup files
  99. Installation
  100. ------------
  101. The process for installing U-Boot on the target device is device specific.
  102. Please, refer to the board specific documentation :doc:`../board/index`.