FirmwareCI Base Image

This repository provides modular, reproducible NixOS base images for FirmwareCI and custom hardware testing. It is intended as a robust foundation for building your own NixOS-based CI images, offering flexible configuration of kernel, firmware, packages, and services. Each image includes essential default tooling, enabling your host machine to execute any FirmwareCI test step reliably.

Note: Chipsec requires an older kernel version for compatibility. To run the chipsec test step, use the provided chipsec configuration or image, which is preconfigured with the appropriate kernel.

For a comprehensive overview of available FirmwareCI commands and usage, refer to the FirmwareCI Commands Reference.

Features

• Nix Flake-based: Modern, reproducible, and composable.
• Easy to extend: Use as a base for your own hardware.

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Quick Start

Prerequisites

• Nix with flakes enabled (experimental-features = nix-command flakes in your nix.conf).

Build All Images

make all

Build a Specific Image

make base
make chipsec

Clean build outputs

make clean

The resulting images will be symlinked as ./base and ./chipsec.

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Flake Structure

• flake.nix – Flake entrypoint, exposes base and chipsec images as outputs.
• modules/base.nix – Base system options and configuration.
• modules/kernel.nix – Kernel options and configuration.
• pkgs/default-tools/default.nix – Default fwci testing tools package.
• Makefile – Simple build automation for images.

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Using as a Base for Your Own Image

You can use this flake as a base for your own NixOS image or configuration.

Example: Extend in Your Own Flake

{
  description = "My Custom FirmwareCI Image";

  inputs.firmwareci-base-image.url = "github:BlindspotSoftware/firmwareci-base-image";

  outputs = { self, nixpkgs, firmwareci-base-image, ... }:
    let
      myHardwareConfig = { ... }: {
        firmwareci.base = {
          sshAccess = {
            user = "root";
            key = "ssh-ed25519 AAAAC3NzaC1lZDI1NTE5AAAAIKcSD9iHnCrJXkSt7aGSnfL0tVHUm+x6/EDr/FchmBfu";
          };
        };

        firmwareci.kernel = {
          version = "6.6.7";
          sha256 = "...";
          extraKernelModules = [ "dummy" "loop" ];
        };
      };
    in {
      nixosConfigurations.my-custom-image = nixpkgs.lib.nixosSystem {
        system = "x86_64-linux";
        modules = [
          firmwareci-base-image.baseConfig
          myHardwareConfig
        ];
      };
    };
}

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Configuration Options

You can override these options in your own configuration or flake:

firmwareci.base options

Option	Type	Default	Description
sshAccess	submodule	{ user = ""; key = ""; }	Add an SSH public key for a user (see below).
enableFwupd	bool	true	Enable the fwupd firmware update service.
enableAllFirmware	bool	true	Enable all available firmware blobs.
allowBroken	bool	true	Allow installation of broken packages.
allowUnfree	bool	true	Allow installation of unfree packages.
includeChipSec	bool	false	Include chipsec with kernel module (<= 6.12 only).
includeDefaultTools	bool	true	Include the default tools package in the image.

sshAccess submodule

Option	Type	Default	Description
user	str	""	SSH user for access (e.g. "root").
key	str	""	SSH public key to add to the user's authorized_keys.

firmwareci.kernel options

Option	Type	Default	Description
version	str	"6.15.8"	Linux kernel version to use.
sha256	str	SRI hash	sha256 hash for the kernel tarball (must be in SRI format, e.g. sha256-...).
extraKernelModules	list of str	[]	Extra kernel modules to load at boot (e.g. ["dummy"]).

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SSH Access and Security

Note:
The default FirmwareCI images are configured to allow SSH access to the root user:

users.users.root.openssh.authorizedKeys.keys = [
    "ssh-ed25519 AAAAC3NzaC1lZDI1NTE5AAAAIKcSD9iHnCrJXkSt7aGSnfL0tVHUm+x6/EDr/FchmBfu"
];

This configuration allows FirmwareCI to securely connect to your device via SSH using a preconfigured key at /root/.ssh/fwci inside the test environment. You may also customize the SSH access settings to suit your specific requirements.

Example SSH transport configuration for FirmwareCI to connect to the machine:

transport: &transport
  proto: ssh
  options:
    host: "my.network"
    user: root
    identity_file: /root/.ssh/fwci #pre-configured SSH-key

Caution:
Do not enable this configuration on devices connected to publicly accessible networks, as it may expose your system to unauthorized access.

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Structure

• flake.nix – Flake entrypoint, exposes base and chipsec images.
• modules/base.nix – Base system options and configuration.
• modules/kernel.nix – Kernel options and configuration.
• pkgs/default-tools/default.nix – Default fwci testing tools package.
• Makefile – Simple build automation for images.

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Development

We welcome contributions from everyone!
Format and lint Nix code with:

nix fmt
nix run .#statix

Pre-commit hooks are available via pre-commit-hooks.nix and will run nixpkgs-fmt and statix on all .nix files before commit.

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License

BSD 2-Clause License

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Maintainers

• @BlindspotSoftware

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Contributing

Contributions and issues are welcome! Please open a PR or issue on GitHub.

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References

• NixOS