nix-repl> import ./. { crossSystem = "thumbv7em-none-eabi" ;}
  error: Unknown CPU type: thumbv7em

In reply to@otanaut:matrix.org
Hey everyone, I am setting up a remote builder VM in my Proxmox environment. The goal is to use this builder to compile x86_64 and aarch64 binaries, as my main system is an Apple Silicon Mac. (Hey, I heard virtualization while you virtualize the virtualizer.)

The builder is up and running and doing its job. To compile aarch64 binaries, I configured boot.binfmt.emulatedSystems = [ "aarch64-linux" ] on the builder. Is there anything else I should consider or that you would recommend, as I am fairly new to the topic?

Thank you!

Artturin: I was hoping I might be able to get a libcxxClang package set by doing crossSystem = { inherit system; custom = true; } (custom = true makes buildPlatform != hostPlatform) and then config.replaceCrossStdenv = { buildPackages, baseStdenv }: buildPackages.libcxxStdenv;.

However this blows up deep in splicing on pkgsTargetTarget. Do you happen to know if there are any threads I can pull on here to make this work?

Artturin: I was hoping I might be able to get a libcxxClang package set by doing crossSystem = { inherit system; custom = true; } (custom = true makes buildPlatform != hostPlatform) and then config.replaceCrossStdenv = { buildPackages, baseStdenv }: buildPackages.libcxxStdenv;.

However this blows up deep in splicing on pkgsTargetTarget (infinite recursion). Do you happen to know if there are any threads I can pull on here to make this work?

Artturin: I was hoping I might be able to get a libcxxClang package set by doing crossSystem = { inherit system; custom = true; } (custom = true makes buildPlatform != hostPlatform) and then config.replaceCrossStdenv = { buildPackages, baseStdenv }: buildPackages.llvmPackages.libstdcxxStdenv; (or similar).

However this blows up deep in splicing on pkgsTargetTarget (infinite recursion). Do you happen to know if there are any threads I can pull on here to make this work?

Would somebody be willing to explain how to use pkgsLLVM to me? My goal is to cross compile using clang, and I know that pkgsLLVM is key, but can't really see how to use it. Additionally, to select the CPU and FPU, do I pass config = { mcpu = "<cpu>"; mfpu = "<fpu>"; }; respectively? Sorry if this is a noob question!

Moreover, is there a way to set sysroot to a different root (i.e. copied off of the target's OS)?