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In Cargo, it is quite typical for "build scripts" to be written in Rust and therefore they need to be compiled as part of the overall build. In cross-compilation, that means a mixed host and target build. Unfortunately, by default Cargo makes no distinction between the RUSTFLAGS used for the host and the target. There is, however, an unstable feature to make this distinction [1][2]. We already have CARGO_TARGET_APPLIES_TO_HOST="false". This makes sure that any configuration that we make for the target doesn't automatically apply to the host as well. However, this only applies for per-target configuration, for example the setting of "cc" in the config.toml generated by package/rust/rust.mk. Flags that are passed with RUSTFLAGS still apply to both host and target. Therefore, we need to use the CARGO_TARGET_<tuple>_RUSTFLAGS environment variable instead of plain RUSTFLAGS. This, however, doesn't allow us to specify flags that apply only to the host. We could use CARGO_TARGET_<hosttuple>_RUSTFLAGS for that, but that doesn't work in case the host and target tuple are the same. For this, we need another unstable feature, enabled with CARGO_UNSTABLE_HOST_CONFIG="true". With this enabled, we can specify flags that apply only for the host build using CARGO_HOST_RUSTFLAGS. Currently, we don't have any such flags, but we really should: we should pass the proper link flags to point to $(HOST_DIR)/lib. Therefore, add CARGO_HOST_RUSTFLAGS doing exactly that. [1] https://doc.rust-lang.org/nightly/cargo/reference/unstable.html#host-config [2] https://github.com/rust-lang/cargo/pull/10395 Signed-off-by: James Hilliard <james.hilliard1@gmail.com> Signed-off-by: Arnout Vandecappelle <arnout@mind.be> |
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| arch | ||
| board | ||
| boot | ||
| configs | ||
| docs | ||
| fs | ||
| linux | ||
| package | ||
| support | ||
| system | ||
| toolchain | ||
| utils | ||
| .checkpackageignore | ||
| .clang-format | ||
| .defconfig | ||
| .flake8 | ||
| .gitignore | ||
| .gitlab-ci.yml | ||
| .shellcheckrc | ||
| 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