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In order to use Clang as a host cross-compiler for Buildroot, we need to provide at least the path to the sysroot (using --sysroot) and some other compiler flags. This series looks to reuse the toolchain wrapper for GCC since Clang support most of the gcc flags used in the Buildroot's toolchain wrapper. The only flag -mfused-madd (deprecated since gcc 4.6) for mips is not supported by clang. Since Clang require gcc >= 5.x this flag can never be used. host-clang refers to an existing GCC-based toolchain (internal or external) for libstdc++. However, a Buildroot external toolchain gets a different BR_CROSS_PATH_SUFFIX. Therefore, we can't reuse the toolchain-wrapper that gets built for the GCC-based toolchain, but instead have to compile an additional clang-specific wrapper, called toolchain-wrapper-clang. After building the clang toolchain wrapper, create the symlinks needed to force package infrastructure to use clang througt the wrapper. Initially clang install the clang-8 binary and create all other symlinks: # clang -> clang-8 # clang++ -> clang # clang-8 # clang-cl -> clang # clang-cpp -> clang Use a post install hook to rename the clang-8 binary to clang-8.br_real and recreate all symlinks: # clang -> toolchain-wrapper-clang # clang++ -> toolchain-wrapper-clang # clang-8 -> toolchain-wrapper-clang # clang-8.br_real # clang++.br_real -> clang-8.br_real # clang.br_real -> clang-8.br_real # clang-cl -> toolchain-wrapper-clang # clang-cl.br_real -> clang-8.br_real # clang-cpp -> toolchain-wrapper-clang # clang-cpp.br_real -> clang-8.br_real NOTE: *.br_real symlinks are needed as the wrapper references them Use the previously introduced CLANG_VERSION_MAJOR variable to create theses symlinks. Set BR_CROSS_PATH_SUFFIX to ".br_real" as for the Buildroot's internal GCC toolchain backend to find the "real" clang binary installed in $(HOST_DIR)/bin. Borrow TOOLCHAIN_WRAPPER_BUILD and TOOLCHAIN_WRAPPER_INSTALL to build and install the specific clang toolchain wrapper. Signed-off-by: Romain Naour <romain.naour@smile.fr> Cc: Valentin Korenblit <valentinkorenblit@gmail.com> Signed-off-by: Matthew Weber <matthew.weber@rockwellcollins.com> Signed-off-by: Arnout Vandecappelle (Essensium/Mind) <arnout@mind.be> |
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| arch | ||
| board | ||
| boot | ||
| configs | ||
| docs | ||
| fs | ||
| linux | ||
| package | ||
| support | ||
| system | ||
| toolchain | ||
| utils | ||
| .clang-format | ||
| .defconfig | ||
| .flake8 | ||
| .gitignore | ||
| .gitlab-ci.yml | ||
| CHANGES | ||
| Config.in | ||
| Config.in.legacy | ||
| COPYING | ||
| DEVELOPERS | ||
| Makefile | ||
| Makefile.legacy | ||
| README | ||
Buildroot is a simple, efficient and easy-to-use tool to generate embedded Linux systems through cross-compilation. The documentation can be found in docs/manual. You can generate a text document with 'make manual-text' and read output/docs/manual/manual.text. Online documentation can be found at http://buildroot.org/docs.html To build and use the buildroot stuff, do the following: 1) run 'make menuconfig' 2) select the target architecture and the packages you wish to compile 3) run 'make' 4) wait while it compiles 5) find the kernel, bootloader, root filesystem, etc. in output/images You do not need to be root to build or run buildroot. Have fun! Buildroot comes with a basic configuration for a number of boards. Run 'make list-defconfigs' to view the list of provided configurations. Please feed suggestions, bug reports, insults, and bribes back to the buildroot mailing list: buildroot@buildroot.org You can also find us on #buildroot on OFTC IRC. If you would like to contribute patches, please read https://buildroot.org/manual.html#submitting-patches