An OpenEmebdded/Yocto layer providing pre-built toolchains for the Rust programming language.
A basic class for cargo-based executables is provided. The following is a simple recipe called gpio_utils.bb that builds the gpio-utils crate from branch master.
SUMMARY = "GPIO Utilities"
HOMEPAGE = "git://github.com/rust-embedded/gpio-utils"
LICENSE = "MIT"
inherit cargo_bin
# Enable network for the compile task allowing cargo to download dependencies
do_compile[network] = "1"
SRC_URI = "git://github.com/rust-embedded/gpio-utils.git;protocol=https;branch=master"
SRCREV="02b0658cd7e13e46f6b1a5de3fd9655711749759"
S = "${WORKDIR}/git"
LIC_FILES_CHKSUM = "file://LICENSE-MIT;md5=935a9b2a57ae70704d8125b9c0e39059"
As you can see, there is almost no overhead introduced from the cargo_bin
class
beyond simply inheriting it. The cargo_bin
class adds the appropriate Rust
dependencies as well as default compile and install steps.
Warning
In previous versions ofmeta-rust-bin
the classcargo
was used instead ofcargo_bin
. Follow this guide if you are updating yourmeta-rust-bin
layer from an old version.
Currently supported:
- Current stable rust release (usually shortly after release) and several previous releases, see the versioned recipes.
- x86 (32 and 64-bit), ARM (32 and 64-bit) build systems.
- All Linux architectures that Rust itself supports (Multiple flavors of: x86, ARM, PPC, and MIPS)
- Statically-linked libstd, dynamically-linked system libraries (libc, libm, etc)
Future:
- Building and installing
dev
andstaticdev
packages (i.e. allow build and install of static and dynamic library builds). - Debug builds with separated debug info to allow gdbserver usage.
- Running Rust/Cargo on target.
- Vendoring of Cargo dependencies (to better play with the Yocto offline build model).
- Use of a shared libstd across all Rust packages on a target system (provides space savings).
- Total static linking using MUSL.
From Yocto version 4.0 network access from tasks is disabled by default on
kernels which support this feature (on most recent distros such as CentOS 8 and
Debian 11 onwards). The task do_compile
need to access the network because it
downloads dependencies, so add the following line to the recipe:
do_compile[network] = "1"
To avoid conflicts with the offical Rust layer of Yocto, the class cargo
of
meta-rust-bin
was renamed to cargo_bin
.
If you are updating meta-rust-bin
from an old version please make sure to
update the inherited class of your recipe to cargo_bin
.
After the update it's safe to remove the previously used BBMASK
:
BBMASK = "poky/meta/recipes-devtools/rust"
Because Yocto is primarily used for embedded development, it is likely that
projects will have differing features based on whether the crate is run on the
hardware or in development on a PC. Cargo features can be easily specified by
adding a space-separated list of CARGO_FEATURES
to the recipe:
CARGO_FEATURES = "feature1 feature2"
Although the cargo
class is the easiest way to use this layer, the components
it provides may also be used directly. To add the Rust compiler plus target and
host standard libraries to the environment, depend on or install rust-bin
. To
manually install cargo
depend on or install cargo-bin
.
Note that while there is nothing explicitly preventing the installation of Rust on the target, it hasn't been tested and is likely not to work. Pull requests are welcome!
This layer exists as a tradeoff against other options, e.g. the meta-rust project. Both exist to satisfy different requirements.
Because this layer uses the upstream compiled versions of Rust and Cargo, it will never be able to support architectures or options not supported by the Rust team itself.
Also, because this layer uses pre-built Rust standard libraries, it is possible that the standard libraries provided with this layer will be less efficient than code produced by a custom-compiled standard library.
However, using pre-built tools has advantages:
- Updating the layer to a new version of Rust is as easy as updating checksums and file names, so new versions of Rust are available quickly.
- In almost all modern systems, it is faster to download the binaries than it is to download source and build the Rust toolchain from scratch.
- Compatability across multiple versions of Yocto is maximized since only basic, stable recipe features are used.
- Trivial support for all architectures supported by upstream Rust.
When a new version of rust is released, adding support for this new version can
be done by running build-new-version.sh
as follows:
./build-new-version.sh <version>
This will create two new recipes:
- recipes-devtools/rust/rust-bin-.bb
- recipes-devtools/rust/cargo-bin-.bb
Where the cargo version generated is the one packaged with the associated release of rust itself (using the published channel data consumed by other tools like rustup).
For latest nightly version:
./build-new-version.sh nightly
For specified nightly version:
./build-new-version.sh nightly 2019-07-08
Copyright (c) 2016, the meta-rust-bin authors.
Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
http://www.apache.org/license/LICENSE-2.0> or the MIT license
<LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
option. This file may not be copied, modified, or distributed
except according to those terms.