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tdro

Another wandering soul screaming into the void. If you are looking for my blog you are in the wrong place. The profile and header pictures are brought to you by @cdd20.

tdro micro.thedroneely.com (edited) view markdown plaintext permalink jan 21 2023 23 sec 68/50 words

Look at this Makefile — then look at this NixOS package derivation. Appears simple but I couldn’t for the life of me divine how to quickly compile a custom/patched kernel module on NixOS. Abstractions… are very magical. The guide is cool and all, but it’s a better time investment to guesstimate the relationship between the higher/lower layer. This friendly example looks more like this in reality though ;-)

#nixos
tdro

Another wandering soul screaming into the void. If you are looking for my blog you are in the wrong place. The profile and header pictures are brought to you by @cdd20.

tdro micro.thedroneely.com view markdown plaintext permalink jan 21 2023 65 sec 194/50 words
A NixOS configuration for a working sound driver on an A1418 Cirrus Logic CS8409/CS42L83.
nix
{ stdenv, lib, fetchgit, linuxKernel, kernel ? linuxKernel.kernels.linux_5_15
, version ? "d0d785dc1859b09299bde6d0f1d6786a0d610e7f" }:

stdenv.mkDerivation {

  inherit version;
  name = "sna-hda-codec-cs8409-${version}-module-${kernel.modDirVersion}";

  # Upstream: https://github.com/davidjo/snd_hda_macbookpro

  src = fetchgit {
    url = "https://github.com/egorenar/snd-hda-codec-cs8409.git";
    rev = version;
    sha256 = "sha256-0UeoERcYpM+ojeZ7dDIE3ruTIoHkkC+s7FcoEVUTR0w=";
  };

  hardeningDisable = [ "pic" ];
  nativeBuildInputs = kernel.moduleBuildDependencies;

  NIX_CFLAGS_COMPILE = [ "-g" "-Wall" "-Wno-unused-variable" "-Wno-unused-function" ];

  makeFlags = kernel.makeFlags ++ [
    "INSTALL_MOD_PATH=$(out)"
    "KERNELRELEASE=${kernel.modDirVersion}"
    "KERNEL_DIR=${kernel.dev}/lib/modules/${kernel.modDirVersion}/build"
  ];

  postPatch = ''
    printf '
    snd-hda-codec-cs8409-objs := patch_cs8409.o patch_cs8409-tables.o
    obj-$(CONFIG_SND_HDA_CODEC_CS8409) += snd-hda-codec-cs8409.o

    KBUILD_EXTRA_CFLAGS = "-DAPPLE_PINSENSE_FIXUP -DAPPLE_CODECS -DCONFIG_SND_HDA_RECONFIG=1"

    KERNELRELEASE ?= $(shell uname -r)
    KERNEL_DIR    ?= /lib/modules/$(KERNELRELEASE)/build
    PWD           := $(shell pwd)

    default:
    	make -C $(KERNEL_DIR) M=$(PWD) CFLAGS_MODULE=$(KBUILD_EXTRA_CFLAGS)

    install:
    	make -C $(KERNEL_DIR) M=$(PWD) modules_install
    ' \
    > Makefile

    sed --in-place 's|<sound/cs42l42.h>|"${linuxKernel.kernels.linux_6_0.dev}/lib/modules/${linuxKernel.kernels.linux_6_0.modDirVersion}/source/include/sound/cs42l42.h"|'  patch_cs8409.h
    sed --in-place 's|hda_local.h|${kernel.dev}/lib/modules/${kernel.modDirVersion}/source/sound/pci/hda/hda_local.h|'                                                      patch_cs8409.h
    sed --in-place 's|hda_jack.h|${kernel.dev}/lib/modules/${kernel.modDirVersion}/source/sound/pci/hda/hda_jack.h|'                                                        patch_cs8409.h
    sed --in-place 's|hda_generic.h|${kernel.dev}/lib/modules/${kernel.modDirVersion}/source/sound/pci/hda/hda_generic.h|'                                                  patch_cs8409.h
    sed --in-place 's|hda_auto_parser.h|${kernel.dev}/lib/modules/${kernel.modDirVersion}/source/sound/pci/hda/hda_auto_parser.h|'                                          patch_cs8409.h
  '';

  meta = { platforms = lib.platforms.linux; };
}
../packages/snd-hda-cs8409/default.nix

Then build it as a extra/custom kernel module. The results of stumbling upon yet another troublesome device…

nix
{ pkgs, ... }:

{
  boot = {
    extraModulePackages = [
      (pkgs.callPackage ../packages/snd-hda-cs8409/default.nix {
        kernel = pkgs.linux_5_15;
      })
    ];
  };
}
hardware.nix
#gists #nixos
tdro

Another wandering soul screaming into the void. If you are looking for my blog you are in the wrong place. The profile and header pictures are brought to you by @cdd20.

tdro micro.thedroneely.com view markdown plaintext permalink jan 5 2023 49 sec 146/50 words
My default nix configuration on NixOS.

This configuration is more for building/debugging stuff and caching with nix-serve. Usually my package version is locked since different versions of nix can have some effects.

nix
{ config, ... }:

{
  nix = {
    package = (import ../versions.nix).nix_2_12 { inherit config; };
    settings = {
      log-lines = 25;                                # https://nixos.org/manual/nix/unstable/command-ref/conf-file.html#conf-log-lines
      fallback = true;                               # https://nixos.org/manual/nix/unstable/command-ref/conf-file.html#conf-fallback
      tarball-ttl = 0;                               # https://nixos.org/manual/nix/unstable/command-ref/conf-file.html#conf-tarball-ttl
      show-trace = true;                             # https://nixos.org/manual/nix/unstable/command-ref/conf-file.html#conf-show-trace
      connect-timeout = 5;                           # https://nixos.org/manual/nix/unstable/command-ref/conf-file.html#conf-connect-timeout
      auto-optimise-store = true;                    # https://nixos.org/manual/nix/unstable/command-ref/conf-file.html#conf-auto-optimise-store
      narinfo-cache-negative-ttl = 0;                # https://nixos.org/manual/nix/unstable/command-ref/conf-file.html#conf-narinfo-cache-negative-ttl
      narinfo-cache-positive-ttl = 0;                # https://nixos.org/manual/nix/unstable/command-ref/conf-file.html#conf-narinfo-cache-positive-ttl
      builders-use-substitutes = true;               # https://nixos.org/manual/nix/unstable/command-ref/conf-file.html#conf-builders-use-substitutes
      min-free = 268435456;                          # https://nixos.org/manual/nix/unstable/command-ref/conf-file.html#conf-min-free (256 MB in Bytes)
      max-free = 1073741824;                         # https://nixos.org/manual/nix/unstable/command-ref/conf-file.html#conf-max-free (1 GB in Bytes)
      allowed-users = [ "root" "@wheel" ];           # https://nixos.org/manual/nix/unstable/command-ref/conf-file.html#conf-allowed-users
      trusted-users = [ "root" "@wheel" ];           # https://nixos.org/manual/nix/unstable/command-ref/conf-file.html#conf-trusted-users
      experimental-features = "nix-command flakes";  # https://nixos.org/manual/nix/unstable/command-ref/conf-file.html#conf-experimental-features
    };
  };
}
My nix-configuration.nix on version 22.11
#gists #nixos
tdro

Another wandering soul screaming into the void. If you are looking for my blog you are in the wrong place. The profile and header pictures are brought to you by @cdd20.

tdro micro.thedroneely.com view markdown plaintext permalink jan 4 2023 32 sec 96/50 words

I thought about posting notes on Syncthing but then I’d have to tangentially talk about NixOS. NixOS is my main Linux distribution but Nix/NixOS/Flakes are too hard to write about and I fear they’ve ventured too far into the realm of over–engineering.

What do I mean by over–engineering? An over–engineered tool is one where even the simplest use cases are non–obvious (to most people) and this can happen when it tries to do too many things with “specificity”. The overall concept is elegant though (explainable in lay terms) and can be applied in other contexts.

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