Cross compilation (Docker) to arm64 and arm/v7

[aaronleopold]

Making this a real issue to hopefully get more visibility. I haven't quite figured out how to get cross-compilation (in Docker) working, an absolutely essential thing to get working so Stump can run on arm systems (e.g. rpi-4).

see https://github.com/aaronleopold/stump/tree/aleopold--arm64-can-sma

[aaronleopold]

same thing will need to be figured out for linux/arm/v7 too

[alxjpzmn]

Have you tried Cross? Any objections of adding it to the project? If not, I'll give it a go later today. Cross compilation to aarch64-unknown-linux-musl & aarch64-unknown-linux-gnu work for me (outside the container for now) using Cross & openssl = { version = "0.10.40", features = ["vendored"] }.

[aaronleopold]

I'm definitely open to trying it! Feel free to give it a go, I did add openssl for arm64 in the Cargo.toml but it'll have to be added for each other target.

[aaronleopold]

Reopening this as compilation is successful for both arm64 and arm/v7, however testing on actual arm devices fails. (stump | exec ./stump: no such file or directory) I spent quite some time trying to figure this out and haven't gotten it yet. At first I thought maybe the build wasn't actually being statically compiled, but enforcing that didn't work. I added binutils in the final stage for debugging and found this:

/app $ readelf -a stump | grep interpreter
      [Requesting program interpreter: /lib/ld-linux-aarch64.so.1]

/lib $ ls
apk                     libc.musl-aarch64.so.1  libz.so.1.2.12
firmware                libcrypto.so.1.1        mdev
ld-musl-aarch64.so.1    libssl.so.1.1           modules-load.d
libapk.so.3.12.0        libz.so.1               sysctl.d

Looks like it is trying to grab something that doesn't exist

Edit: creating a sym link seems to have fixed it! Tested in the already built image creating the link as root (ln -s /lib/ld-musl-aarch64.so.1 /lib/ld-linux-aarch64.so.1) and Stump launched 🎉 Will add to dockerfile and retest this week. Hopefully this can finally fully resolve this issue.

[aaronleopold]

This line

RUN ln -s /lib/ld-musl-aarch64.so.1 /lib/ld-linux-aarch64.so.1; exit 0

fixes the docker image for arm64, now I will just have to fix arm/v7 and can close this issue.

[aaronleopold]

Closing for #27