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From: NoisyCoil <noisycoil@disroot.org>
Newsgroups: linux.debian.kernel
Subject: Re: Package for development of out-of-tree kernel modules written in  Rust
Date: Sun, 13 Apr 2025 17:40:01 +0200
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On 13/04/25 13:14, Bastian Blank wrote:
> So we can only ship rust source in any way and the
> kernel module make stuff needs to rebuild anything for the external
> modules.

Yep, this seems to work [1]. The two tests I did are:

1. Native build on arm64. Installed the build on amd64, replaced the 
Rust files (rmeta and libmacros) with ones obtained by cross-compiling 
the same kernel with the same config on amd64. Pointing KDIR to the 
natively-built /usr/src/linux-headers with the replaced Rust files 
correctly builds the OOT module, and the module correctly loads on arm64.

2. Cross-build on amd64. Installed the build on arm64, replaced the Rust 
files with those from the twin native build. Same as above, the module 
builds and correctly loads on arm64.

This seems to be the way to go, although my limited testing may well be 
neglecting unknown failure modes.


[1] At least with MODVERSIONS enabled. Not sure what would happen with 
MODVERSIONS disabled, perhaps nothing, as long as the kernel version 
remains the same?