Cross-compiling Rust from Windows to ARM Linux

For MacOS better use: musleabihf, for Windows you can use gnueabihf as bellow:

Mac

$ brew install arm-linux-gnueabihf-binutils
$ rustup target add armv7-unknown-linux-musleabihf

In .cargo/config

[build]
target = "armv7-unknown-linux-musleabihf"
[target.armv7-unknown-linux-c]
linker = "arm-linux-gnueabihf-ld"

With simple src/main.rs

fn main() {
    println!("Hello, Raspberry!");
}

Then things are fine:

Hasans-Air:rpi hasan$ cargo build
   Compiling rpi v0.1.0 (/Users/hasan/PycharmProjects/rpi)
    Finished dev [unoptimized + debuginfo] target(s) in 0.41s
Hasans-Air:rpi hasan$ scp target/armv7-unknown-linux-musleabihf/debug/rpi [email protected]:
[email protected]'s password: 
rpi                                                                                         100% 2702KB   2.6MB/s   00:01    
Hasans-Air:rpi hasan$ ssh [email protected] 'chmod +x ~/rpi && ~/rpi'
[email protected]'s password: 
Hello, Raspberry!

Win 10 Get the linker from here, and run:

rustup target add armv7-unknown-linux-gnueabihf

Creating file .cargo/config with content:

[build]
target = "armv7-unknown-linux-gnueabihf"

[target.armv7-unknown-linux-gnueabihf]
linker = "arm-linux-gnueabihf-gcc"

And with simple src/main.rs:

fn main() {
    println!("Hello, Raspberry! from Win 10");
}

I was able to get things done

Thanks to @Notlikethat's comment:

a) Yes you need to provide your own GCC cross-compiler.

b) You can get one here (select a mingw32 build).

Just unzip linaro's GCC then point cargo to it:

[target.armv7-unknown-linux-gnueabihf]
linker = "C:/Users/me/gcc-linaro-5.3.1-2016.05-i686-mingw32_arm-linux-gnueabihf/bin/arm-linux-gnueabihf-gcc.exe"

It seems to work even though it is arm- and not armv7-. I guess linking doesn't depend on the ISA. Actually I haven't run it yet, but it builds without errors!

Edit:

You can now use armv7-unknown-linux-musleabihf instead and get an actually portable binary (i.e. it doesn't depend on the GNU C library which often causes compatibility issues).