liminix/devices/belkin-rt3200/default.nix

{
  description = ''
    Belkin RT-3200 / Linksys E8450
    ******************************

    This device is based on a 64 bit Mediatek MT7622 ARM platform,
    and is mostly feature-complete in Liminix but as of Dec 2024
    has seen very little actual use.

    Hardware summary
    ================

    - MediaTek MT7622BV (1350MHz)
    - 128MB NAND flash
    - 512MB	RAM
    - b/g/n wireless using MediaTek MT7622BV (MT7615E driver)
    - a/n/ac/ax wireless using  MediaTek MT7915E


    Installation
    ============

    Liminix on this device uses the UBI volume management system to
    perform wear leveling on the flash. This is not set up from the
    factory, so a one-time step is needed to prepare it before Liminix
    can be installed.


    Preparation
    -----------

    To prepare the device for Liminix you first need to use the
    `OpenWrt UBI Installer
    <https://github.com/dangowrt/owrt-ubi-installer>`_ image to
    rewrite the flash layout. As of Jan 2025 there are two versions
    of the installer available: the release version 1.0.2 and the
    pre-release 1.1.3 and for Liminix you nee the pre-relese.
    The release version of the installer creates UBI volumes
    according to an older layout that is not compatible with
    the Linux 6.6.67 kernel used in Liminix.

    You can run the installer in one of two ways:
    either follow the instructions to do it through the vendor web
    interface, or you can drop to U-Boot and use TFTP

    .. code-block:: console

        MT7622> setenv ipaddr 10.0.0.6
        MT7622> setenv serverip 10.0.0.1
        MT7622> tftpboot 0x42000000  openwrt-mediatek-mt7622-linksys_e8450-ubi-initramfs-recovery-installer.itb
        MT7622> bootm 0x42000000

    This will write the new flash layout and then boot into a
    "recovery" OpenWrt installation.

    Building/installing Liminix
    ----------------

    The default target for this device is ``outputs.ubimage`` which
    makes a ubifs image suitable for use with :command:`ubiupdatevol`.
    To write this to the device we use the OpenWrt recovery system
    installed in the previous step. In this configuration the
    device assigns itself the IP address 192.168.1.1/24 on its LAN
    ports and expects the connected computer to have 192.168.1.254

    .. warning:: The `ubi0_7` device in these instructions is correct
                 as of Dec 2024 (dangowrt/owrt-ubi-installer commit
                 d79e7928). If you are installing some time later, it
                 is important to check the output from
                 :command:`ubinfo -a` and make sure you are updating
                 the "liminix" volume and not some other one which had
                 been introduced since I wrote this.

    .. code-block:: console

        $ nix-build -I liminix-config=./my-configuration.nix  --arg device "import ./devices/belkin-rt3200" -A outputs.default
        $ cat result/rootfs | ssh root@192.168.1.1 "cat > /tmp/rootfs"
        $ ssh root@192.168.1.1
        root@OpenWrt:~# ubimkvol /dev/ubi0 --name=liminix --maxavsize
        root@OpenWrt:~# ubinfo -a
        [...]
        Volume ID:   7 (on ubi0)
        Type:        dynamic
        Alignment:   1
        Size:        851 LEBs (108056576 bytes, 103.0 MiB)
        State:       OK
        Name:        liminix
        Character device major/minor: 250:8
        root@OpenWrt:~# ubiupdatevol /dev/ubi0_7 /tmp/rootfs

    To make the new system bootable we also need to change some U-Boot variables.
    ``boot_production`` needs to mount the filesystem and boot the FIT image
    found there, and :code:`bootcmd` needs to be told _not_ to boot the rescue
    image if there are records in pstore, because that interferes with
    ``config.log.persistent``

    .. code-block:: console

        root@OpenWrt:~# fw_setenv orig_boot_production $(fw_printenv -n boot_production)
        root@OpenWrt:~# fw_setenv orig_bootcmd $(fw_printenv -n bootcmd)
        root@OpenWrt:~# fw_setenv boot_production 'led $bootled_pwr on ; ubifsmount ubi0:liminix && ubifsload ''${loadaddr} boot/fit && bootm ''${loadaddr}'
        root@OpenWrt:~# fw_setenv bootcmd 'run boot_ubi'

    For subsequent Liminix reinstalls, just run the
    :command:`ubiupdatevol` command again. You don't need to repeat
    the "Preparation" step and in fact should seek to avoid it if
    possible, as it will reset the erase counters used for write
    levelling.  Using UBI-aware tools is therefore preferred over any
    kind of "factory" wipe which will reset them.
  '';

  system = {
    crossSystem = {
      config = "aarch64-unknown-linux-musl";
    };
  };

  module =
    {
      pkgs,
      config,
      lib,
      lim,
      ...
    }:
    let
      inherit (lib) mkIf;
      firmware = pkgs.stdenv.mkDerivation {
        name = "wlan-firmware";
        phases = [ "installPhase" ];
        installPhase = ''
          mkdir $out
          cp ${pkgs.linux-firmware}/lib/firmware/mediatek/{mt7915,mt7615,mt7622}* $out
        '';
      };
      openwrt = pkgs.openwrt_24_10;
    in
    {
      imports = [
        ../../modules/arch/aarch64.nix
        ../../modules/outputs/tftpboot.nix
        ../../modules/outputs/ubifs.nix
      ];
      config = {
        kernel = {
          extraPatchPhase = ''
            ${openwrt.applyPatches.mediatek}
          '';
          src = openwrt.kernelSrc;
          version = openwrt.kernelVersion;
          config = {
            PCI = "y";
            ARCH_MEDIATEK = "y";
            # ARM_MEDIATEK_CPUFREQ = "y";

            # needed for "Cannot find regmap for /infracfg@10000000"
            MFD_SYSCON = "y";
            MTK_INFRACFG = "y";

            MTK_PMIC_WRAP = "y";
            DMADEVICES = "y";
            MTK_HSDMA = "y";
            MTK_SCPSYS = "y";
            MTK_SCPSYS_PM_DOMAINS = "y";
            # MTK_THERMAL="y";
            MTK_TIMER = "y";

            COMMON_CLK_MT7622 = "y";
            COMMON_CLK_MT7622_ETHSYS = "y";
            COMMON_CLK_MT7622_HIFSYS = "y";
            COMMON_CLK_MT7622_AUDSYS = "y";
            PM_CLK = "y";

            REGMAP_MMIO = "y";
            CLKSRC_MMIO = "y";
            REGMAP = "y";

            MEDIATEK_GE_PHY = "y";
            # MEDIATEK_MT6577_AUXADC = "y";
            NET_MEDIATEK_SOC = "y";
            NET_MEDIATEK_SOC_WED = "y";
            NET_MEDIATEK_STAR_EMAC = "y"; # this enables REGMAP_MMIO
            NET_VENDOR_MEDIATEK = "y";
            PCIE_MEDIATEK = "y";

            BLOCK = "y"; # move this to base option

            SPI_MASTER = "y";
            SPI = "y";
            SPI_MEM = "y";
            SPI_MTK_NOR = "y";
            SPI_MTK_SNFI = "y";

            MTD = "y";
            MTD_BLOCK = "y";
            MTD_RAW_NAND = "y";
            MTD_NAND_MTK = "y";
            MTD_NAND_MTK_BMT = "y"; # Bad-block Management Table
            MTD_NAND_ECC_MEDIATEK = "y";
            MTD_NAND_ECC_SW_HAMMING = "y";
            MTD_SPI_NAND = "y";
            MTD_OF_PARTS = "y";
            MTD_NAND_CORE = "y";
            MTD_SPI_NOR = "y";
            MTD_SPLIT_FIRMWARE = "y";
            MTD_SPLIT_FIT_FW = "y";

            MTD_UBI_NVMEM = "y";
            NVMEM_MTK_EFUSE = "y";
            NVMEM_BLOCK = "y";
            NVMEM_LAYOUT_ADTRAN = "y";

            MMC = "y";
            MMC_BLOCK = "y";
            MMC_CQHCI = "y";
            MMC_MTK = "y";

            # Distributed Switch Architecture is needed
            # to make the ethernet ports visible
            NET_DSA = "y";
            NET_DSA_MT7530 = "y";
            NET_DSA_TAG_MTK = "y";
            NET_DSA_MT7530_MDIO = "y";

            SERIAL_8250 = "y";
            SERIAL_8250_CONSOLE = "y";
            SERIAL_8250_MT6577 = "y";
            # SERIAL_8250_NR_UARTS="3";
            # SERIAL_8250_RUNTIME_UARTS="3";
            SERIAL_OF_PLATFORM = "y";

            # Must enble hardware watchdog drivers. Else the device reboots after several seconds
            WATCHDOG = "y";
            MEDIATEK_WATCHDOG = "y";
          };
          conditionalConfig = {
            WLAN = {
              MT7615E = "m";
              MT7622_WMAC = "y";
              MT7915E = "m";
            };
          };
        };
        boot = {
          commandLine = [ "console=ttyS0,115200" ];
          tftp.loadAddress = lim.parseInt "0x48000000";
          imageFormat = "fit";
          loader.fit.enable = lib.mkDefault true; # override this if you are building tftpboot
        };
        rootfsType = lib.mkDefault "ubifs"; # override this if you are building tftpboot
        filesystem =
          let
            inherit (pkgs.pseudofile) dir symlink;
          in
          dir {
            lib = dir {
              firmware = dir {
                mediatek = symlink firmware;
              };
            };
          };

        hardware =
          let
            mac80211 = pkgs.kmodloader.override {
              targets = [
                "mt7615e"
                "mt7915e"
              ];
              inherit (config.system.outputs) kernel;
            };
          in
          {
            ubi = {
              minIOSize = "2048";
              logicalEraseBlockSize = "126976";
              physicalEraseBlockSize = "131072";
              maxLEBcount = "1024"; # guessing
            };

            defaultOutput = "ubimage";
            # the kernel expects this to be on a 2MB boundary. U-Boot
            # (I don't know why) has a default of 0x41080000, which isn't.
            # We put it at the 32MB mark so that tftpboot can put its rootfs
            # image and DTB underneath, but maybe this is a terrible waste of
            # RAM unless the kernel is able to reuse it later. Oh well
            loadAddress = lim.parseInt "0x42000000";
            entryPoint = lim.parseInt "0x42000000";
            rootDevice = "ubi0:liminix";
            dts = {
              src = "${openwrt.src}/target/linux/mediatek/dts/mt7622-linksys-e8450-ubi.dts";
              includePaths = [
                "${openwrt.src}/target/linux/mediatek/dts"
                "${config.system.outputs.kernel.modulesupport}/arch/arm64/boot/dts/mediatek/"
              ];
              includes = mkIf config.logging.persistent.enable [
                ./pstore-pmsg.dtsi
              ];
            };

            # - 0x000000000000-0x000008000000 : "spi-nand0"
            #         - 0x000000000000-0x000000080000 : "bl2"
            #         - 0x000000080000-0x0000001c0000 : "fip"
            #         - 0x0000001c0000-0x0000002c0000 : "factory"
            #         - 0x0000002c0000-0x000000300000 : "reserved"
            #         - 0x000000300000-0x000008000000 : "ubi"

            networkInterfaces =
              let
                inherit (config.system.service.network) link;
              in
              rec {
                wan = link.build { ifname = "wan"; };
                lan1 = link.build { ifname = "lan1"; };
                lan2 = link.build { ifname = "lan2"; };
                lan3 = link.build { ifname = "lan3"; };
                lan4 = link.build { ifname = "lan4"; };
                lan = lan3;

                wlan = link.build {
                  ifname = "wlan0";
                  dependencies = [ mac80211 ];
                };
                wlan5 = link.build {
                  ifname = "wlan1";
                  dependencies = [ mac80211 ];
                };
              };
          };
      };
    };
}