Static Linking of aarch64 target / buildroot

help
1

Hi!
I need some support, again. Currently i set up an 'minimal embedded linux' with the help of buildroot, which runs on a raspberry PI 4. As in my other thread mentioned, I need some 'drivers' for different sensors, which I have written in Rust. When writing these, i used the 0815 raspbian os, which has 'everything' on board and also a lot of boilerplate stuff so my final goal is to have only the kernel running with minimal overhead.

Now i have to compile the Rust-Sources from my host (x86_64) to the aarch64 Architecture. There are a bunch of tutorials, so it outcomes like this:

foo: ELF 64-bit LSB pie executable, ARM aarch64, version 1 (SYSV), dynamically linked, interpreter /lib/ld-linux-aarch64.so.1, BuildID[sha1]=e17920ca987e387e221bb5a32e0c0d347294b421, for GNU/Linux 3.7.0, with debug_info, not stripped

So far so good. When running it on my custom buildroot linux, the outcome looks like that:

# ./foo 
-/bin/sh: ./foo: not found

Oops, but the file is there! Okay, i found out, that the problem occurs because of the dynamic linking and, of course, on my system almost nothing exists. If i copy 'ld-linux-aarch64.so.1' into /lib, the programs 'starts', but claims the next missing lib.

Long story short: Is there a way to compile every dynamic lib into the binary so that it may run standalone? I searched a while for it and found nothing appropriate for this use case.
In C language it's really simple to do this and I get programs running standalone on this 'minimal linux', but hey, rewrite the driver in C would feel like i 'lost the war'. Would be great to 'embedd' rust programs into buildroot

Edit:
My C Programs look like this:

# file am2302 
am2302: ELF 64-bit LSB executable e, ARM aarch64, ....

So propably we need an executable instead of 'shared object'

2

Try with a …-musl (rather than …-gnu) target and/or the +crt-static flag

1 Like
3

Nice, thank you for the hint, i'll try that out! :+1:

5

I had several problems with ...-musl and linking on my host system, so I found a 'lazy way' to achieve the goal by using this :

It works fine now on my buildroot system (with the setting named by Yandros), of course not perfect if you don't know exactly why the 'handmade solution' fails but it will come with more experience i guess :slight_smile:

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