I wanted to run a thing I'm building with Rust on my Surface Pro X which is an ARM64 device the other day. My initial thought when I got the idea, was "I hope it's not complicated to do".
TLDR; it wasn't.
One thing to be aware of is that ARM64, or
aarch64-pc-windows-msvc as the toolchain
target is known as, is that it belongs in
tier 2 of Rust's platform support.
While tier 1 is "Guaranteed to run", tier 2 is only "Guaranteed to build".
Tier 2 platforms can be thought of as "guaranteed to build". Automated tests are not run, so it's not guaranteed to produce a working build, but platforms often work to quite a good degree [...]
So what do the different parts in the toolchain target name mean?
||This is the platform architecture we're targeting, in this case, ARM64.|
||This is the operating system we're targeting, in this case, Windows.|
||This is the compiler we want to use. MSVC is an abbreviation of "Microsoft Visual C++".|
If you're interested in reading more about the different supported platforms
in Rust, you can find the full list over at
Installing the toolchain target
Rust supports cross-compilation, so there's no need to build our ARM64 app on an ARM64 machine, and even if we wanted to, it would prove difficult since essential tools like Cargo isn't available for ARM64 on Windows. The only prerequisite for cross-compiling is a compiler that can target the desired platform and all the necessary dependencies required to compile the code.
To compile our application for ARM64, we need to install the
aarch64-pc-windows-msvc target for our Rust compiler toolchain.
> rustup target install aarch64-pc-windows-msvc
If you want to see what toolchain targets are available or installed, you can
rustup target list command.
> rustup target list aarch64-apple-ios aarch64-fuchsia aarch64-linux-android aarch64-pc-windows-msvc (installed) aarch64-unknown-linux-gnu
Building for ARM64
Now when the correct toolchain target has been installed, let's go ahead and create a new binary and build it with our newly installed target.
> cargo build --target=aarch64-pc-windows-msvc Compiling helloworld v0.1.0 (D:\Source\local\helloworld) Finished dev [unoptimized + debuginfo] target(s) in 0.36s
Automatically build with a specific target
If you always want to build for this target, you can create
in your repository root and add the following contents to it:
[build] target = "aarch64-pc-windows-msvc"
Running on an ARM64 machine
Everything compiled! Not a big surprise, it's "Guaranteed to build" after all, but it felt good anyway. Time to test it out on an actual ARM64 machine.
> ./helloworld.exe -1073741515
The application exited with the error code
more famously known as
0xC0000135, which is Windows' way of telling us that
an essential component is missing. It turns out that we need to install the
Microsoft Visual C++ Redistributable for Visual Studio 2019
Installing the MSVC redistributable and rerunning our app now produces the expected output.
> ./helloworld.exe Hello World
Not super complicated stuff, but hopefully this post has been useful for you if you wanted to learn more about Rust's different platform tiers, toolchain targets, and cross-compilation.