nix-loongarch-kernel

Linux stable kernel with additional patches for LoongArch platforms.

Check available versions in tags, though staying up-to-date with main is recommended.

Patches

• HWMon support for Loongson 3 family processors
• PixArt PS/2 touchpad driver
• Legacy firmware boot support and AMD GPU stability fixes
• Full patch list: https://loongfans.cn/pages/sdk.html

Motorcomm YT6801 Ethernet Controller

On kernel 6.19 and earlier, YT6801 support was provided by an out-of-tree driver imported from AOSC/Deepin (CONFIG_YT6801, Motorcomm SDK, ~17000 lines).

Starting with kernel 7.0, this repository uses the mainline driver dwmac-motorcomm by Yao Zi, enabled via CONFIG_DWMAC_MOTORCOMM=m (which selects MOTORCOMM_PHY). The old YT6801 patches have been dropped. Related submission history: https://lwn.net/Articles/1016815/.

Parameter comparison between the two drivers

Captured on identical YT6801 hardware (PCI 1f0a:6801) with ethtool against the same link partner.

ethtool -i	old yt6801 (6.19)	new dwmac-motorcomm (7.0)
driver	yt6801	st_gmac
version	1.0.27	kernel version
firmware-version	S.D.U: 52.0.10	(empty)
supports-register-dump	yes	yes

ethtool -g (rings)	old	new
RX max / current	1024 / 1024	1024 / 512
TX max / current	256 / 256	1024 / 512

ethtool -c (coalesce)	old	new
rx-usecs	200	327
tx-usecs	200	5000
tx-frames	n/a	25

ethtool -k (features, selected)	old	new
highdma	off [fixed]	on [fixed]
receive-hashing	on	off [fixed]
rx-vlan-filter	on	off [fixed]
tx-vlan-offload	on	on [fixed]

ethtool (link)	old	new
Supported ports	[ MII ]	[ TP MII ]
Transceiver	internal	external
Link partner info	not reported	reported

Binary Cache

To speed up builds, you can use the binary cache provided by nix4loong.cn:

nix.extraOptions = ''
  extra-substituters = https://cache.nix4loong.cn
  extra-trusted-public-keys = cache.nix4loong.cn-1:zmkwLihdSUyy6OFSVgvK3br0EaUEczLiJgDfvOmm3pA=
'';

Alternatively, use the installation image from nix4loong.cn, which comes with the cache and the kernel pre-configured.

Usage

Option 1: NixOS Module (Recommended)

This method is recommended as it can take full advantage of the binary cache.

{
  inputs.nix-loongarch-kernel.url = "github:darkyzhou/nix-loongarch-kernel";

  outputs = { self, nixpkgs, nix-loongarch-kernel, ... }: {
    nixosConfigurations.myhost = nixpkgs.lib.nixosSystem {
      system = "loongarch64-linux";
      modules = [
        nix-loongarch-kernel.nixosModules.default
      ];
    };
  };
}

Option 2: Overlay

Note: Using an overlay may not hit the binary cache due to different derivation hashes.

{
  inputs.nix-loongarch-kernel.url = "github:darkyzhou/nix-loongarch-kernel";

  outputs = { self, nixpkgs, nix-loongarch-kernel, ... }: {
    nixosConfigurations.myhost = nixpkgs.lib.nixosSystem {
      system = "loongarch64-linux";
      modules = [
        {
          nixpkgs.overlays = [ nix-loongarch-kernel.overlay ];
          boot.kernelPackages = pkgs.linuxPackages-nix4loong;
        }
      ];
    };
  };
}

Acknowledgements

Special thanks to loongfans.cn and all the patch authors for their contributions.