Building RISC OS Executables with Nix: A Practical Guide
successfully building software for diverse platforms can be a important challenge.You might encounter unexpected hurdles, especially when dealing with less common architectures like RISC OS. fortunately, the nix package manager offers a powerful and reproducible way to tackle these builds. This guide will walk you through creating a RISC OS executable using Nix, saving you valuable time and frustration.
Understanding the Challenge
Traditionally, cross-compilation requires meticulous habitat setup and dependency management. Nix simplifies this process by providing isolated build environments. This ensures consistency and reproducibility, regardless of your host system. Building for RISC OS is no exception, and with a few key steps, you can reliably generate executables for this unique platform.
Setting Up Your Project
First, you’ll need a basic C program. Let’s start with a simple “Hello, RISC OS!” exmaple. Create a file named hello.c with the following content:
#include <stdio.h>
int main() {
printf("Hello, RISC OS!n");
return 0;
}This is the core of your request.Now, you’ll define the Nix derivation that orchestrates the build process.
The Nix Derivation: A Step-by-Step breakdown
Create a file named default.nix in the same directory as hello.c. This file will contain the instructions for building your RISC OS executable. Here’s a breakdown of the key components:
{ pkgs, lib }:
pkgs.stdenv.mkDerivation {
pname = "hello-riscos";
version = "1.0";
src = ./.;
hardeningDisable = [ "all" ];
buildPhase = ''
echo CC=$CC
$CC hello.c -o hello
elf2aif hello
'';
installPhase = ''
mkdir -p $out/bin
cp hello $out/bin
'';
}Let’s dissect this derivation:
* { pkgs, lib }: This line defines the input arguments to your Nix expression. pkgs provides access to pre-built packages, and lib offers utility functions.
* pkgs.stdenv.mkDerivation { ... }: This is the core function for creating a Nix package. It takes an attribute set containing build instructions.
* pname = "hello-riscos"; This sets the package name.
* version = "1.0"; This specifies the package version.
* src = ./.; This indicates that the source code is located in the current directory.
* hardeningDisable = [ "all" ]; Disables hardening flags, which can sometimes interfere with RISC OS compatibility.
* buildPhase = '' ... ''; This defines the commands to execute during the build phase.
* echo CC=$CC displays the C compiler being used.
* $CC hello.c -o hello compiles the C code into an ELF executable.
* elf2aif hello converts the ELF executable to the RISC OS AIF format. You’ll need to ensure elf2aif is available in your environment or within the Nix store.
* installPhase = '' ...''; This defines the commands to install the built executable.
* mkdir -p $out/bin creates the bin directory within the Nix store.
* cp hello $out/bin copies the AIF executable to the bin directory.
Building and Testing Your Executable
Now, you can build your RISC OS executable using the
