wip it good

tftp needs to be able to follow symlinks into the store

.gitignore

@@ -6,3 +6,4 @@ result-*
 _build
 *-secrets.nix
 examples/static-leases.nix
+/doc/hardware.rst

NEWS

@@ -0,0 +1,105 @@
+A brief guide to backward-incompatible changes
+that are likely to break configurations or workflows
+
+2023-07-13
+
+* a significant re-arrangement of modules and services, which will
+probably break any configuration written before this time. For a
+detailed explanation, see
+https://www.liminix.org/doc/configuration.html#modules
+
+2023-12-10
+
+* configurations (usually) need no longer import modules from
+modules/outputs because devices are expected to do this instead. This
+change is because the outputs that make sense in any given context are
+usually a property of the device being installed onto.
+
+2023-12-11
+
+* rename outputs.flashimage to outputs.mtdimage (and also diskimage to
+mbrimage). This change is made in the expectation that "fooimage" is
+the name of an outputs that gloms together other filesystem-like
+outputs with some kind of partition table - so we might in future have
+gptimage or lvmimage or ubimage.
+
+2024-01-03
+
+Liminix is now targeted to Nixpkgs 23.11 (not 23.05 as previously).
+Upstream changes that have led to incompatible Liminix changes are:
+
+* newer U-Boot version
+* util-linux can now be built (previously depended on systemd)
+
+2024-01-30
+
+New port! Thanks to Arnout Engelen <arnout@bzzt.net>, Liminix
+now runs on the TP-Link Archer AX23.
+
+2024-02-12
+
+* We now build wifi drivers (mac80211) from the same kernel source as
+the running kernel, instead of using drivers from the linux-backports
+project.  This may be a regression on some devices that depend on
+OpenWrt patches for wireless functionality: if you have a device that
+used to work and now doesn't, refer to OpenWrt
+package/kernel/mac80211/patches/ to see if there's something in there
+that needs to be applied.
+
+* in general, we build kernel modules (e.g. for nftables) at the same
+time as the kernel itself instead of expecting to be able to build
+them afterwards as though they were "out of tree". Refer to commit
+b9c0d93670275e69df24902b05bf4aa4f0fcbe96 for a fuller explanation
+of how this simplifies things.
+
+2024-02-13
+
+So that we can be more consistent about services that would like their
+state to be preserved across boots (assuming a writable filesystem)
+these changes have been made
+
+* /run/service-state has been moved to /run/services/outputs
+ to better reflect what it's used for
+* /run/services/state is either a symlink to /persist/services/state
+ (if there's a writeable fs on /persist) or a directory (if there
+ isn't)
+
+The change will lose your ssh host key(s) unless you copy them from
+the old location to the new one before rebooting into the new system
+
+   mkdir -m 02751 -p /run/services/state/dropbear
+   cp /persist/secrets/dropbear/* /run/services/state/dropbear
+
+The `output`, `mkoutputs` functions defined by ${serviceFns}
+have been updated for the new location.
+
+2024-02-16
+
+New (or at least, previously unreported) port! Liminix now runs on the
+Turris Omnia and has been serving my family's internet needs for most
+of this week.  Thanks to NGI0 Entrust and the NLnet Foundation for
+sponsoring this development (and funding the hardware)
+
+2024-02-21
+
+New port! Thanks to Raito Bezarius, Liminix now runs on the Zyxel NWA50AX,
+an MT7621 (MIPS EL) dual radio WiFi AP.
+
+2024-04-29
+
+The setup for using `levitate` has changed: now it accepts an entire
+config fragment, not just a list of services.  Hopefully this makes it
+a bit more useful :-)
+
+  defaultProfile.packages = with pkgs; [
+    ... 
+    (levitate.override {
+      config  = {
+        services = {
+          inherit (config.services) dhcpc sshd watchdog;
+        };
+        defaultProfile.packages = [ mtdutils ];
+        users.root.openssh.authorizedKeys.keys = secrets.root.keys;
+      };
+    })
+  ];

README.md

@@ -18,22 +18,14 @@ outside word goes across it.
 
 Liminix is pre-1.0. We are still finding new and better ways to do things,
 and there is no attempt to maintain backward compatibility with the old
-ways. This will change when it settles down.
+ways.
 
-_In general:_ development mostly happens on the `main` branch, which is
-therefore not guaranteed to build or to work on every commit. For the
-latest functioning version, see [the CI system](https://build.liminix.org/jobset/liminix/build) and pick a revision with all jobs green.
+The [NEWS](NEWS) file (available wherever you found this README) is
+a high-level overview of breaking changes.
 
-_In particular:_ as of July 2023, a significant re-arrangement of
-modules and services is ongoing:
-
-* if you are using out-of-tree configurations created before commit
-  2e50368, especially if they reference things under pkgs.liminix,
-  they will need updating. Look at changes to examples/rotuer.nix
-  for guidance
-
-* the same is intermittently true for examples/{extensino,arhcive}.nix
-  where I've updated rotuer and not updated them to match.
+Development mostly happens on the `main` branch, which is therefore
+not guaranteed to build or to work on every commit. For the latest
+functioning version, see [the CI system](https://build.liminix.org/jobset/liminix/build) and pick a revision with all jobs green.
 
 
 ## Documentation
@@ -41,7 +33,7 @@ modules and services is ongoing:
 Documentation is in the [doc](doc/) directory. You can build it
 by running
 
-    nix-shell -p sphinx --run "make -C doc html"
+    nix-shell -p sphinx --run "make -C doc hardware.rst html"
 
 Rendered documentation corresponding to the latest commit on `main`
 is published to [https://www.liminix.org/doc/](https://www.liminix.org/doc/)

boot.expect

@@ -0,0 +1,20 @@
+# This is for use with minicom, but needs you to configure it to
+# use expect as its "Script program" instead of runscript.  Try
+# Ctrl+A O -> Filenames and paths -> D
+
+log_user 0
+log_file -a -open stderr
+set f [open "result/boot.scr"]
+send "version\r"
+set timeout 60
+while {[gets $f line] >= 0} {
+    puts stderr "next line $line\r"
+    puts stderr "waiting for prompt\r"	
+    expect {
+      "ath>" {}
+      "BusyBox" { puts stderr  "DONE"; exit 0 }
+    }
+    send "$line\r\n"
+}
+puts stderr "done\r\n"
+close $f

bordervm-configuration.nix

@@ -4,6 +4,10 @@ let
   inherit (lib) mkOption mkEnableOption mdDoc types optional optionals;
 in {
   options.bordervm = {
+    keys = mkOption {
+      type = types.listOf types.str;
+      default = [ ];
+    };
     l2tp = {
       host = mkOption {
         description = mdDoc ''
@@ -51,18 +55,17 @@ in {
     <nixpkgs/nixos/modules/virtualisation/qemu-vm.nix>
   ];
   config = {
-    boot.kernelParams = [
-      "loglevel=9"
-    ];
+    boot.kernelParams = [ "loglevel=9" ];
     systemd.services.pppoe =
-      let conf = pkgs.writeText "kpppoed.toml"
-        ''
-      interface_name = "eth1"
-      services = [ "myservice" ]
-      lns_ipaddr = "${cfg.l2tp.host}:${builtins.toString cfg.l2tp.port}"
-      ac_name = "kpppoed-1.0"
-    '';
-      in  {
+      let
+        conf = pkgs.writeText "kpppoed.toml" ''
+          interface_name = "eth1"
+          services = [ "myservice" ]
+          lns_ipaddr = "${cfg.l2tp.host}:${builtins.toString cfg.l2tp.port}"
+          ac_name = "kpppoed-1.0"
+        '';
+      in
+      {
         wantedBy = [ "multi-user.target" ];
         after = [ "network-online.target" ];
         serviceConfig = {
@@ -76,37 +79,52 @@ in {
       };
     };
     services.openssh.enable = true;
+    services.dnsmasq = {
+      enable = true;
+      resolveLocalQueries = false;
+      settings = {
+        # domain-needed = true;
+        dhcp-range = [ "10.0.0.10,10.0.0.240" ];
+        interface = "eth1";
+      };
+    };
+
     systemd.services.sshd.wantedBy = pkgs.lib.mkForce [ "multi-user.target" ];
 
     virtualisation = {
       qemu = {
-        networkingOptions = [];
-        options = [] ++
-          optional cfg.ethernet.pci.enable
-            "-device vfio-pci,host=${cfg.ethernet.pci.id}" ++
-          optionals cfg.ethernet.usb.enable [
+        networkingOptions = [ ];
+        options =
+          [ ]
+          ++ optional cfg.ethernet.pci.enable "-device vfio-pci,host=${cfg.ethernet.pci.id}"
+          ++ optionals cfg.ethernet.usb.enable [
             "-device usb-ehci,id=ehci"
             "-device usb-host,bus=ehci.0,vendorid=${cfg.ethernet.usb.vendor},productid=${cfg.ethernet.usb.product}"
-          ] ++ [
+          ]
+          ++ [
             "-nographic"
             "-serial mon:stdio"
           ];
       };
       sharedDirectories = {
         liminix = {
+          securityModel = "none";
           source = builtins.toString ./.;
           target = "/home/liminix/liminix";
         };
       };
     };
-    environment.systemPackages = with pkgs; [
-      tcpdump
-      wireshark
-      socat
-      tufted
-      iptables
-      usbutils
-    ];
+    environment.systemPackages =
+      let wireshark-nogui = pkgs.wireshark.override { withQt = false ; };
+          in with pkgs; [
+            tcpdump
+            wireshark-nogui
+            socat
+            tufted
+            iptables
+            usbutils
+            busybox
+          ];
     security.sudo.wheelNeedsPassword = false;
     networking = {
       hostName = "border";
@@ -115,11 +133,17 @@ in {
         useDHCP = false;
         ipv4.addresses = [ { address = "10.0.0.1"; prefixLength = 24;}];
       };
+      nat = {
+        enable = true;
+        internalInterfaces = [ "eth1" ];
+        externalInterface = "eth0";
+      };
     };
     users.users.liminix = {
       isNormalUser = true;
       uid = 1000;
-      extraGroups = [ "wheel"];
+      extraGroups = [ "wheel" ];
+      openssh.authorizedKeys.keys = cfg.keys;
     };
     services.getty.autologinUser = "liminix";
   };

bordervm.conf-example.nix

@@ -1,8 +1,12 @@
-{...}:
+{ ... }:
 {
   bordervm = {
     # ethernet.pci = { id = "01:00.0"; enable = true; };
-    ethernet.usb = { vendor = "0x0bda"; product = "0x8153"; enable = true; };
+    ethernet.usb = {
+      vendor = "0x0bda";
+      product = "0x8153";
+      enable = true;
+    };
     l2tp = {
       host = "l2tp.aa.net.uk";
     };

ci.nix

@@ -1,14 +1,23 @@
 {
-  nixpkgs
-, unstable
-, liminix
-, ... }:
+  nixpkgs,
+  unstable,
+  liminix,
+  ...
+}:
 let
-  inherit (builtins) map;
-  pkgs = (import nixpkgs {});
-  borderVmConf =  ./bordervm.conf-example.nix;
+  pkgs = (import nixpkgs { });
+  borderVmConf = ./bordervm.conf-example.nix;
   inherit (pkgs.lib.attrsets) genAttrs;
-  devices = [ "qemu" "gl-ar750" "gl-mt300n-v2" "gl-mt300a" ];
+  devices = [
+    "gl-ar750"
+    "gl-mt300a"
+    "gl-mt300n-v2"
+    "qemu"
+    "qemu-aarch64"
+    "qemu-armv7l"
+    "tp-archer-ax23"
+    "zyxel-nwa50ax"
+  ];
   vanilla = ./vanilla-configuration.nix;
   for-device = name:
     (import liminix {
@@ -18,33 +27,52 @@ let
     }).outputs.default;
   tests = import ./tests/ci.nix;
   jobs =
-    (genAttrs devices (name: for-device name)) //
-    tests //
-    {
-      buildEnv = (import liminix {
-        inherit nixpkgs  borderVmConf;
-        device = import (liminix + "/devices/qemu");
-        liminix-config = vanilla;
-      }).buildEnv;
-      doc = pkgs.stdenv.mkDerivation {
-        name = "liminix-doc";
-        nativeBuildInputs = with pkgs; [
-          gnumake sphinx
-          fennel luaPackages.lyaml
-        ];
-        src = ./doc;
-        buildPhase = ''
-          cat ${(import ./doc/extract-options.nix).doc} > options.json
-          cat options.json | fennel --correlate parse-options.fnl > modules-generated.rst
-          make html
-        '';
-        installPhase = ''
-          mkdir -p $out/nix-support $out/share/doc/
-          cp modules.rst options.json $out
-          cp -a _build/html $out/share/doc/liminix
-          echo "file source-dist \"$out/share/doc/liminix\"" \
-              > $out/nix-support/hydra-build-products
-        '';
+    (genAttrs devices for-device)
+    // tests
+    // {
+      buildEnv =
+        (import liminix {
+          inherit nixpkgs borderVmConf;
+          device = import (liminix + "/devices/qemu");
+          liminix-config = vanilla;
+        }).buildEnv;
+      doc =
+        let
+          json =
+            (import liminix {
+              inherit nixpkgs borderVmConf;
+              device = import (liminix + "/devices/qemu");
+              liminix-config =
+                { ... }:
+                {
+                  imports = [ ./modules/all-modules.nix ];
+                };
+            }).outputs.optionsJson;
+        in
+        pkgs.stdenv.mkDerivation {
+          name = "liminix-doc";
+          nativeBuildInputs = with pkgs; [
+            gnumake
+            sphinx
+            fennel
+            luaPackages.lyaml
+          ];
+          src = ./.;
+          buildPhase = ''
+            cat ${json} | fennel --correlate doc/parse-options.fnl > doc/modules-generated.rst
+            cat ${json} | fennel --correlate doc/parse-options-outputs.fnl     > doc/outputs-generated.rst
+            cp ${(import ./doc/hardware.nix)} doc/hardware.rst
+            make -C doc html
+          '';
+          installPhase = ''
+            mkdir -p $out/nix-support $out/share/doc/
+            cd doc
+            cp *-generated.rst  $out
+            ln -s ${json} $out/options.json
+            cp -a _build/html $out/share/doc/liminix
+            echo "file source-dist \"$out/share/doc/liminix\"" \
+                > $out/nix-support/hydra-build-products
+          '';
       };
       with-unstable = (import liminix {
         nixpkgs = unstable;

default.nix

@@ -1,41 +1,62 @@
 {
-  device
-, liminix-config ? <liminix-config>
-, nixpkgs ? <nixpkgs>
-, borderVmConf ? ./bordervm.conf.nix
+  deviceName ? null,
+  device ? (import ./devices/${deviceName}),
+  liminix-config ? <liminix-config>,
+  nixpkgs ? <nixpkgs>,
+  borderVmConf ? ./bordervm.conf.nix,
+  imageType ? "primary",
 }:
 
 let
   overlay = import ./overlay.nix;
-  pkgs = import nixpkgs (device.system // {
-    overlays = [overlay];
-    config = {
-      allowUnsupportedSystem = true; # mipsel
-      permittedInsecurePackages = [
-        "python-2.7.18.6"       # kernel backports needs python <3
-      ];
-    };
-  });
+  pkgs = import nixpkgs (
+    device.system
+    // {
+      overlays = [ overlay ];
+      config = {
+        allowUnsupportedSystem = true; # mipsel
+        permittedInsecurePackages = [
+          "python-2.7.18.6" # kernel backports needs python <3
+          "python-2.7.18.7"
+        ];
+      };
+    }
+  );
 
-  config = (pkgs.lib.evalModules {
+  eval = pkgs.lib.evalModules {
+    specialArgs = {
+      modulesPath = builtins.toString ./modules;
+    };
     modules = [
-      { _module.args = { inherit pkgs; lib = pkgs.lib; }; }
+      { _module.args = { inherit pkgs; inherit (pkgs) lim; }; }
       ./modules/hardware.nix
       ./modules/base.nix
       ./modules/busybox.nix
       ./modules/hostname.nix
+      ./modules/kernel
       device.module
       liminix-config
       ./modules/s6
       ./modules/users.nix
       ./modules/outputs.nix
+      {
+        boot.imageType = imageType;
+      }
     ];
-  }).config;
+  };
+  config = eval.config;
 
   borderVm = ((import <nixpkgs/nixos/lib/eval-config.nix>) {
     system = builtins.currentSystem;
     modules = [
-      ({  ... } : { nixpkgs.overlays = [ overlay ]; })
+      {
+        nixpkgs.overlays = [
+          (final: prev: {
+            go-l2tp = final.callPackage ./pkgs/go-l2tp {};
+            tufted = final.callPackage ./pkgs/tufted {};
+          })
+        ];
+      }
       (import ./bordervm-configuration.nix)
       borderVmConf
     ];
@@ -43,6 +64,12 @@ let
 in {
   outputs = config.system.outputs // {
     default = config.system.outputs.${config.hardware.defaultOutput};
+    optionsJson =
+      let o = import ./doc/extract-options.nix {
+            inherit pkgs eval;
+            lib = pkgs.lib;
+          };
+      in pkgs.writeText "options.json" (builtins.toJSON o);
   };
 
   # this is just here as a convenience, so that we can get a
@@ -54,11 +81,13 @@ in {
       tufted
       routeros.routeros
       routeros.ros-exec-script
-      mips-vm
+      run-liminix-vm
       borderVm.build.vm
       go-l2tp
       min-copy-closure
       fennelrepl
+      lzma
+      lua
     ];
   };
 }

devices/belkin-rt3200/default.nix

@@ -0,0 +1,236 @@
+{
+  description = ''
+    Belkin RT-3200 / Linksys E8450
+    ******************************
+
+    This device is based on a 64 bit Mediatek MT7622 ARM platform,
+    and is "work in progress" in Liminix.
+
+    .. note:: The factory flash image contains ECC errors that make it
+              incompatible with Liminix: you need to use the `OpenWrt
+              UBI Installer <https://github.com/dangowrt/owrt-ubi-installer>`_ to
+              rewrite the partition layout before you can flash
+              Liminix onto it (or even use it with
+              :ref:`system-outputs-tftpboot`, if you want the wireless
+              to work).
+
+    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
+    ============
+
+    Installation is currently a manual process (you need a :ref:`serial <serial>` conection and
+    TFTP) following the instructions at :ref:`system-outputs-ubimage`
+
+'';
+
+  system = {
+    crossSystem = {
+      config = "aarch64-unknown-linux-musl";
+    };
+  };
+
+  module = {pkgs, config, lib, lim, ... }:
+    let firmware = pkgs.stdenv.mkDerivation {
+          name = "wlan-firmware";
+          phases = ["installPhase"];
+          installPhase = ''
+            mkdir $out
+            cp ${pkgs.linux-firmware}/lib/firmware/mediatek/{mt7915,mt7615,mt7622}* $out
+          '';
+        };
+    in {
+      imports = [
+        ../../modules/arch/aarch64.nix
+        ../../modules/outputs/tftpboot.nix
+        ../../modules/outputs/ubifs.nix
+      ];
+      config = {
+    kernel = {
+      src = pkgs.pkgsBuildBuild.fetchurl {
+        name = "linux.tar.gz";
+        url = "https://cdn.kernel.org/pub/linux/kernel/v5.x/linux-5.15.137.tar.gz";
+        hash = "sha256-PkdzUKZ0IpBiWe/RS70J76JKnBFzRblWcKlaIFNxnHQ=";
+      };
+      extraPatchPhase = ''
+          ${pkgs.openwrt.applyPatches.mediatek}
+      '';
+      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";
+        NVMEM_MTK_EFUSE="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";
+
+
+        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";
+
+        PSTORE = "y";
+        PSTORE_RAM = "y";
+        PSTORE_CONSOLE = "y";
+        PSTORE_DEFLATE_COMPRESS = "n";
+
+        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 "0x4007ff28";
+      imageFormat = "fit";
+    };
+    filesystem =
+      let inherit (pkgs.pseudofile) dir symlink;
+           in
+             dir {
+               lib = dir {
+                 firmware = dir {
+                   mediatek = symlink firmware;
+                 };
+               };
+             };
+
+    hardware =
+      let
+        openwrt = pkgs.openwrt;
+        mac80211 =  pkgs.kmodloader.override {
+          targets = ["mt7615e" "mt7915e"];
+          inherit (config.system.outputs) kernel;
+        };
+      in {
+        ubi = {
+          minIOSize = "2048";
+          eraseBlockSize = "126976";
+          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";
+          includes =  [
+            "${openwrt.src}/target/linux/mediatek/dts"
+            "${config.system.outputs.kernel.modulesupport}/arch/arm64/boot/dts/mediatek/"
+          ];
+        };
+
+        # - 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 ];
+            };
+          };
+      };
+      };
+  };
+}

devices/families/qemu.nix

@@ -0,0 +1,62 @@
+{ config, pkgs, ... }:
+{
+  imports = [
+    ../../modules/outputs/jffs2.nix
+  ];
+  config = {
+    kernel = {
+      src = pkgs.pkgsBuildBuild.fetchurl {
+        name = "linux.tar.gz";
+        url = "https://cdn.kernel.org/pub/linux/kernel/v5.x/linux-5.15.137.tar.gz";
+        hash = "sha256-PkdzUKZ0IpBiWe/RS70J76JKnBFzRblWcKlaIFNxnHQ=";
+      };
+      config = {
+        MTD = "y";
+        MTD_BLOCK = "y";
+        MTD_CMDLINE_PARTS = "y";
+        MTD_PHRAM = "y";
+
+        VIRTIO_MENU = "y";
+        PCI = "y";
+        VIRTIO_PCI = "y";
+        BLOCK = "y";
+        VIRTIO_BLK = "y";
+        VIRTIO_NET = "y";
+      };
+      conditionalConfig = {
+        WLAN= {
+          MAC80211_HWSIM = "m";
+        };
+      };
+    };
+    hardware =
+      let
+        mac80211 =  pkgs.kmodloader.override {
+          inherit (config.system.outputs) kernel;
+          targets = ["mac80211_hwsim"];
+        };
+      in {
+        defaultOutput = "vmroot";
+        rootDevice = "/dev/mtdblock0";
+        dts.src = pkgs.lib.mkDefault null;
+        flash.eraseBlockSize = 65536;
+        networkInterfaces =
+          let inherit (config.system.service.network) link;
+          in {
+            wan = link.build {
+              devpath = "/devices/pci0000:00/0000:00:13.0/virtio0";
+              ifname = "wan";
+            };
+            lan = link.build {
+              devpath = "/devices/pci0000:00/0000:00:14.0/virtio1";
+              ifname = "lan";
+            };
+
+            wlan_24 = link.build {
+              ifname = "wlan0";
+              dependencies = [ mac80211 ];
+            };
+          };
+      };
+  };
+}

devices/gl-ar750/default.nix

@@ -1,11 +1,3 @@
-
-# I like GL.iNet devices because they're relatively accessible to
-# DIY users: the serial port connections have headers preinstalled
-# and don't need soldering
-
-# Mainline linux 5.19 doesn't have device-tree support for this device
-# or even for the SoC, so we use the extensive OpenWrt kernel patches
-
 {
   system = {
     crossSystem = {
@@ -18,27 +10,49 @@
   };
 
   description = ''
-    GL.INet GL-AR750 "Creta" travel router
+    GL.iNet GL-AR750
+    ****************
+
+    Hardware summary
+    ================
+
+    The GL-AR750 "Creta" travel router features:
+
      - QCA9531 @650Mhz SoC
      - dual band wireless: IEEE 802.11a/b/g/n/ac
      - two 10/100Mbps LAN ports and one WAN
-     - 128MB DDR2 RAM / 16MB  NOR Flash
-     - "ath79" soc family
-    https://www.gl-inet.com/products/gl-ar750/
+     - 128MB DDR2 RAM
+     - 16MB NOR Flash
+     - supported in OpenWrt by the "ath79" SoC family
 
     The GL-AR750 has two distinct sets of wifi hardware. The 2.4GHz
     radio is part of the QCA9531 SoC, i.e. it's on the same silicon as
     the CPU, the Ethernet, the USB etc. The device is connected to the
-    host via AHB, the "Advanced High-Performance Bus" and it is
-    supported in Linux using the ath9k driver. The 5GHz support, on the
-    other hand, is provided by a QCA9887 PCIe (PCI embedded) WLAN chip:
-    I haven't looked closely at the router innards to see if this is
-    actually physically a separate board that could be unplugged, but
-    as far as the Linux is concerned it behaves as one. This is
+    host via `AHB <https://en.wikipedia.org/wiki/Advanced_Microcontroller_Bus_Architecture>`_ and it is
+    supported in Linux using the ath9k driver. 5GHz wifi
+    is provided by a QCA9887 PCIe (PCI embedded) WLAN chip,
     supported by the ath10k driver.
+
+    Installation
+    ============
+
+    As with many GL.iNet devices, the stock vendor firmware
+    is a fork of OpenWrt, meaning that the binary created by
+    :ref:`system-outputs-mtdimage` can be flashed using the
+    vendor web UI or the U-Boot emergency "unbrick" routine.
+
+    For flashing from an existing Liminix system (we believe that) it
+    is necessary to first boot into a :ref:`system-outputs-kexecboot`
+    system, otherwise you'll be overwriting flash partitions while
+    they're in use - and that might not end well.
+
+    Vendor web page: https://www.gl-inet.com/products/gl-ar750/
+
+    OpenWrt web page: https://openwrt.org/toh/gl.inet/gl-ar750
+
   '';
 
-  module = {pkgs, config, ... }:
+  module = {pkgs, config, lim, ... }:
     let
       openwrt = pkgs.openwrt;
       firmwareBlobs = pkgs.pkgsBuildBuild.fetchFromGitHub {
@@ -57,14 +71,15 @@
           cp $blobdir/board.bin  $out/ath10k/QCA9887/hw1.0/
         '';
       };
-      mac80211 = pkgs.mac80211.override {
-        drivers = ["ath9k" "ath10k_pci"];
-        klibBuild = config.system.outputs.kernel.modulesupport;
+      mac80211 = pkgs.kmodloader.override {
+        targets = ["ath9k" "ath10k_pci"];
+        inherit (config.system.outputs) kernel;
+        dependencies = [ ath10k_cal_data ];
       };
       ath10k_cal_data =
         let
-          offset = 1024 * 20; # 0x5000
-          size = 2048 + 68; # 0x844
+          offset = lim.parseInt "0x5000";
+          size = lim.parseInt "0x844";
         in pkgs.liminix.services.oneshot rec  {
           name = "ath10k_cal_data";
           up = ''
@@ -77,21 +92,26 @@
         '';
       };
       inherit (pkgs.pseudofile) dir symlink;
-      inherit (pkgs.liminix.networking) interface;
     in {
-      imports = [ ../../modules/network];
+      imports = [
+        ../../modules/network
+        ../../modules/arch/mipseb.nix
+        ../../modules/outputs/tftpboot.nix
+        ../../modules/outputs/mtdimage.nix
+        ../../modules/outputs/jffs2.nix
+      ];
 
       programs.busybox.options = {
         FEATURE_DD_IBS_OBS = "y"; # ath10k_cal_data needs skip_bytes,fullblock
       };
       hardware = {
-        defaultOutput = "flashimage";
-        loadAddress = "0x80060000";
-        entryPoint  = "0x80060000";
+        defaultOutput = "mtdimage";
+        loadAddress = lim.parseInt "0x80060000";
+        entryPoint = lim.parseInt "0x80060000";
         flash = {
-          address = "0x9F060000";
-          size ="0xfa0000";
-          eraseBlockSize = "65536";
+          address = lim.parseInt "0x9F060000";
+          size = lim.parseInt "0xfa0000";
+          eraseBlockSize = 65536;
         };
         rootDevice = "/dev/mtdblock5";
         dts = {
@@ -104,15 +124,23 @@
         networkInterfaces =
           let inherit (config.system.service.network) link;
           in {
-            lan = link.build { ifname = "eth0"; };
-            wan = link.build { ifname = "eth1"; };
-            wlan_24 = link.build {
+            lan = link.build {
+              ifname = "lan";
+              #              devpath = "/devices/platform/ahb/19000000.eth";
+              devpath = "/devices/platform/ahb/1a000000.eth";
+            };
+            wan = link.build {
+              ifname = "wan";
+              devpath = "/devices/platform/ahb/19000000.eth";
+              # devpath = "/devices/platform/ahb/1a000000.eth";
+            };
+            wlan = link.build {
               ifname = "wlan0";
               dependencies = [ mac80211 ];
             };
-            wlan_5 = link.build {
+            wlan5 = link.build {
               ifname = "wlan1";
-              dependencies = [ mac80211 ath10k_cal_data ];
+              dependencies = [ ath10k_cal_data mac80211  ];
             };
           };
       };
@@ -127,21 +155,26 @@
         };
       };
       boot.tftp = {
-        loadAddress = "0x00A00000";
+        loadAddress = lim.parseInt "0x00A00000";
+        appendDTB = true;
       };
       kernel = {
         src = pkgs.pkgsBuildBuild.fetchurl {
           name = "linux.tar.gz";
-          url = "https://cdn.kernel.org/pub/linux/kernel/v5.x/linux-5.15.71.tar.gz";
-          hash = "sha256-yhO2cXIeIgUxkSZf/4aAsF11uxyh+UUZu6D1h92vCD8=";
+          url = "https://cdn.kernel.org/pub/linux/kernel/v5.x/linux-5.15.137.tar.gz";
+          hash = "sha256-PkdzUKZ0IpBiWe/RS70J76JKnBFzRblWcKlaIFNxnHQ=";
         };
+
+        # Mainline linux 5.19 doesn't have device-tree support for
+        # this device or even for the SoC, so we use the extensive
+        # OpenWrt kernel patches
         extraPatchPhase = ''
           ${openwrt.applyPatches.ath79}
+          sed -i.bak -e '\,include <linux/hw_random.h>,a #include <linux/gpio/driver.h>'  drivers/net/wireless/ath/ath9k/ath9k.h # context reqd for next patch
+          patch -p1 <  ${openwrt.src}/package/kernel/mac80211/patches/ath9k/552-ath9k-ahb_of.patch
         '';
+
         config = {
-          MIPS_ELF_APPENDED_DTB = "y";
-          OF = "y";
-          USE_OF = "y";
           ATH79 = "y";
           PCI = "y";
           PCI_AR724X = "y";
@@ -161,7 +194,6 @@
           CONSOLE_LOGLEVEL_QUIET = "4";
 
           NET = "y";
-          NETDEVICES = "y";
           ETHERNET = "y";
           NET_VENDOR_ATHEROS = "y";
           AG71XX = "y";             # ethernet (qca,qca9530-eth)
@@ -169,7 +201,6 @@
           AR8216_PHY = "y";         # eth1 is behind a switch
 
           MTD_SPI_NOR = "y";
-          MTD_SPI_NOR_USE_4K_SECTORS = "n";  # jffs2 needs min 8k erase block
 
           SPI_ATH79 = "y";      # these are copied from OpenWrt.
           SPI_MASTER= "y";      # At least one of them is necessary
@@ -186,24 +217,26 @@
           SYSFS = "y";
           SPI = "y";
           MTD = "y";
-          MTD_CMDLINE_PARTS = "y";
           MTD_BLOCK = "y";          # fix undefined ref to register_mtd_blktrans_devs
 
           WATCHDOG = "y";
           ATH79_WDT = "y";  # watchdog timer
 
-          CPU_BIG_ENDIAN= "y";
-
-          # this is all copied from nixwrt ath79 config. Clearly not all
-          # of it is device config, some of it is wifi config or
-          # installation method config or ...
-
-          CMDLINE_PARTITION = "y";
           EARLY_PRINTK = "y";
 
-          PARTITION_ADVANCED = "y";
           PRINTK_TIME = "y";
         };
+        conditionalConfig = {
+          WLAN = {
+            WLAN_VENDOR_ATH = "y";
+            ATH_COMMON = "m";
+            ATH9K = "m";
+            ATH9K_AHB = "y";
+            ATH10K = "m";
+            ATH10K_PCI = "m";
+            ATH10K_DEBUG = "y";
+          };
+        };
       };
     };
 }

devices/gl-mt300a/default.nix

@@ -1,4 +1,4 @@
-# GL.INet GL-MT300A
+# GL.iNet GL-MT300A
 
 {
   system = {
@@ -12,25 +12,55 @@
   };
 
   description = ''
+    GL.iNet GL-MT300A
+    *****************
+
+    The GL-MT300A is based on a MT7620 chipset.
+
+    For flashing from U-Boot, the firmware partition is from
+    0xbc050000 to 0xbcfd0000.
+
     WiFi on this device is provided by the rt2800soc module. It
     expects firmware to be present in the "factory" MTD partition, so
     - assuming we want to use the wireless - we need to build MTD
-    support into the kernel even if we're using TFTP root
+    support into the kernel even if we're using TFTP root.
+
+    Installation
+    ============
+
+    The stock vendor firmware is a fork of OpenWrt, meaning that the
+    binary created by :ref:`system-outputs-mtdimage` can be flashed
+    using the vendor web UI or the U-Boot emergency "unbrick" routine.
+
+    For flashing from an existing Liminix system (we think) it
+    is necessary to first boot into a :ref:`system-outputs-kexecboot`
+    system, otherwise you'll be overwriting flash partitions while
+    they're in use - and that might not end well.
+
+    Vendor web page: https://www.gl-inet.com/products/gl-mt300a/
+
+    OpenWrt web page: https://openwrt.org/toh/gl.inet/gl-mt300a
+
   '';
 
-  module = { pkgs, config, lib, ...}:
+  module = { pkgs, config, lib, lim, ...}:
     let
-      inherit (pkgs.liminix.networking) interface;
       inherit (pkgs) openwrt;
-      mac80211 = pkgs.mac80211.override {
-        drivers = ["rt2800soc"];
-        klibBuild = config.system.outputs.kernel.modulesupport;
+      mac80211 = pkgs.kmodloader.override {
+        targets = ["rt2800soc"];
+        inherit (config.system.outputs) kernel;
       };
-     in {
+    in {
+      imports = [
+        ../../modules/arch/mipsel.nix
+        ../../modules/outputs/tftpboot.nix
+        ../../modules/outputs/mtdimage.nix
+        ../../modules/outputs/jffs2.nix
+      ];
       hardware = {
-        defaultOutput = "flashimage";
-        loadAddress = "0x80000000";
-        entryPoint  = "0x80000000";
+        defaultOutput = "mtdimage";
+        loadAddress = lim.parseInt "0x80000000";
+        entryPoint = lim.parseInt "0x80000000";
 
         # Creating 5 MTD partitions on "spi0.0":
         # 0x000000000000-0x000000030000 : "u-boot"
@@ -43,9 +73,9 @@
         # 0x000000260000-0x000000f80000 : "rootfs"
 
         flash = {
-          address = "0xbc050000";
-          size ="0xf80000";
-          eraseBlockSize = "65536";
+          address = lim.parseInt "0xbc050000";
+          size = lim.parseInt "0xf80000";
+          eraseBlockSize = 65536;
         };
         rootDevice = "/dev/mtdblock5";
 
@@ -59,19 +89,6 @@
           let
             inherit (config.system.service.network) link;
             inherit (config.system.service) vlan;
-            inherit (pkgs.liminix.services) oneshot;
-            swconfig = oneshot {
-              name = "swconfig";
-              up = ''
-                PATH=${pkgs.swconfig}/bin:$PATH
-                swconfig dev switch0 set reset
-                swconfig dev switch0 set enable_vlan 1
-                swconfig dev switch0 vlan 1 set ports '1 2 3 4 6t'
-                swconfig dev switch0 vlan 2 set ports '0 6t'
-                swconfig dev switch0 set apply
-              '';
-              down = "${pkgs.swconfig}/bin/swconfig dev switch0 set reset";
-            };
           in rec {
             eth = link.build { ifname = "eth0"; };
             # lan and wan ports are both behind a switch on eth0
@@ -79,13 +96,11 @@
               ifname = "eth0.1";
               primary = eth;
               vid = "1";
-              dependencies =  [swconfig eth];
             };
             wan = vlan.build {
               ifname = "eth0.2";
               primary = eth;
               vid = "2";
-              dependencies =  [swconfig eth];
             };
             wlan = link.build {
               ifname = "wlan0";
@@ -94,22 +109,21 @@
           };
       };
       boot.tftp = {
-        loadAddress = "0x00A00000";
-      };
+        loadAddress = lim.parseInt "0x00A00000";
+        appendDTB = true;
+     };
 
       kernel = {
         src = pkgs.fetchurl {
           name = "linux.tar.gz";
-          url = "https://cdn.kernel.org/pub/linux/kernel/v5.x/linux-5.15.71.tar.gz";
-          hash = "sha256-yhO2cXIeIgUxkSZf/4aAsF11uxyh+UUZu6D1h92vCD8=";
+          url = "https://cdn.kernel.org/pub/linux/kernel/v5.x/linux-5.15.137.tar.gz";
+          hash = "sha256-PkdzUKZ0IpBiWe/RS70J76JKnBFzRblWcKlaIFNxnHQ=";
         };
         extraPatchPhase = ''
           ${openwrt.applyPatches.ramips}
+          ${openwrt.applyPatches.rt2x00}
         '';
         config = {
-          MIPS_ELF_APPENDED_DTB = "y";
-          OF = "y";
-          USE_OF = "y";
 
           RALINK = "y";
           PCI = "y";
@@ -124,7 +138,6 @@
           CONSOLE_LOGLEVEL_QUIET = "4";
 
           NET = "y";
-          NETDEVICES = "y";
           ETHERNET = "y";
           NET_VENDOR_RALINK = "y";
           NET_RALINK_MDIO = "y";
@@ -140,22 +153,25 @@
           SPI_MEM= "y";
 
           MTD = "y";
-          MTD_CMDLINE_PARTS = "y";
           MTD_BLOCK = "y";         # fix undefined ref to register_mtd_blktrans_devs
 
-          CPU_LITTLE_ENDIAN = "y";
-
-          CMDLINE_PARTITION = "y";
           EARLY_PRINTK = "y";
 
           NEW_LEDS = "y";
           LEDS_CLASS = "y";         # required by rt2x00lib
 
-          PARTITION_ADVANCED = "y";
           PRINTK_TIME = "y";
         } // lib.optionalAttrs (config.system.service ? vlan) {
           SWCONFIG = "y";
         };
+        conditionalConfig = {
+          WLAN = {
+            WLAN_VENDOR_RALINK = "y";
+            RT2800SOC = "m";
+            RT2X00 = "m";
+          };
+        };
+
       };
     };
 }

devices/gl-mt300n-v2/default.nix

@@ -1,5 +1,3 @@
-# GL.INet GL-MT300N v2
-
 {
   system = {
     crossSystem = {
@@ -11,22 +9,54 @@
     };
   };
 
-  module = { pkgs, config, lib, ...}:
+  description = ''
+    GL.iNet GL-MT300N-v2
+    ********************
+
+    The GL-MT300N-v2 "Mango" is is very similar to the :ref:`MT300A <GL.iNet GL-MT300A>, but is
+    based on the MT7628 chipset instead of MT7620.  It's also marginally cheaper
+    and comes in a yellow case not a blue one.  Be sure your device is
+    v2 not v1, which is a different animal and has only half as much RAM.
+
+    Installation
+    ============
+
+    The stock vendor firmware is a fork of OpenWrt, meaning that the
+    binary created by :ref:`system-outputs-mtdimage` can be flashed
+    using the vendor web UI or the U-Boot emergency "unbrick" routine.
+
+    For flashing from an existing Liminix system (we think) it
+    is necessary to first boot into a :ref:`system-outputs-kexecboot`
+    system, otherwise you'll be overwriting flash partitions while
+    they're in use - and that might not end well.
+
+    Vendor web page: https://www.gl-inet.com/products/gl-mt300n-v2/
+
+    OpenWrt web page: https://openwrt.org/toh/gl.inet/gl-mt300n_v2
+
+  '';
+
+  module = { pkgs, config, lib, lim, ...}:
     let
-      inherit (pkgs.liminix.networking) interface;
       inherit (pkgs.liminix.services) oneshot;
       inherit (pkgs.pseudofile) dir symlink;
       inherit (pkgs) openwrt;
 
-      mac80211 = pkgs.mac80211.override {
-        drivers = ["mt7603e"];
-        klibBuild = config.system.outputs.kernel.modulesupport;
+      mac80211 = pkgs.kmodloader.override {
+        targets = ["mt7603e"];
+        inherit (config.system.outputs) kernel;
       };
       wlan_firmware = pkgs.fetchurl {
         url = "https://github.com/openwrt/mt76/raw/f24b56f935392ca1d35fae5fd6e56ef9deda4aad/firmware/mt7628_e2.bin";
         hash = "sha256:1dkhfznmdz6s50kwc841x3wj0h6zg6icg5g2bim9pvg66as2vmh9";
       };
     in {
+      imports = [
+        ../../modules/arch/mipsel.nix
+        ../../modules/outputs/tftpboot.nix
+        ../../modules/outputs/mtdimage.nix
+        ../../modules/outputs/jffs2.nix
+      ];
       filesystem = dir {
         lib = dir {
           firmware = dir {
@@ -35,14 +65,14 @@
         };
       };
       hardware = {
-        defaultOutput = "flashimage";
-        loadAddress = "0x80000000";
-        entryPoint  = "0x80000000";
+        defaultOutput = "mtdimage";
+        loadAddress = lim.parseInt "0x80000000";
+        entryPoint = lim.parseInt "0x80000000";
 
         flash = {
-          address = "0xbc050000";
-          size = "0xfb0000";
-          eraseBlockSize = "65536";
+          address = lim.parseInt "0xbc050000";
+          size = lim.parseInt "0xfb0000";
+          eraseBlockSize = 65536;
         };
         rootDevice = "/dev/mtdblock5";
 
@@ -66,7 +96,7 @@
                 swconfig dev switch0 vlan 2 set ports '0 6t'
                 swconfig dev switch0 set apply
               '';
-              down = "swconfig dev switch0 set reset";
+              down = "${pkgs.swconfig}/bin/swconfig dev switch0 set reset";
             };
           in rec {
             eth = link.build { ifname = "eth0"; dependencies =  [swconfig]; };
@@ -90,27 +120,24 @@
       boot.tftp = {
         # 20MB seems to give enough room to uncompress the kernel
         # without anything getting trodden on. 10MB was too small
-        loadAddress = "0x1400000";
+        loadAddress = lim.parseInt "0x1400000";
+        appendDTB = true;
       };
 
       kernel = {
         src = pkgs.fetchurl {
           name = "linux.tar.gz";
-          url = "https://cdn.kernel.org/pub/linux/kernel/v5.x/linux-5.15.71.tar.gz";
-          hash = "sha256-yhO2cXIeIgUxkSZf/4aAsF11uxyh+UUZu6D1h92vCD8=";
+          url = "https://cdn.kernel.org/pub/linux/kernel/v5.x/linux-5.15.137.tar.gz";
+          hash = "sha256-PkdzUKZ0IpBiWe/RS70J76JKnBFzRblWcKlaIFNxnHQ=";
         };
         extraPatchPhase = ''
           ${openwrt.applyPatches.ramips}
         '';
         config = {
-          MIPS_ELF_APPENDED_DTB = "y";
-          OF = "y";
-          USE_OF = "y";
 
           RALINK = "y";
           PCI = "y";
           SOC_MT7620 = "y";
-          CPU_LITTLE_ENDIAN= "y";
 
           SERIAL_8250_CONSOLE = "y";
           SERIAL_8250 = "y";
@@ -121,7 +148,6 @@
           CONSOLE_LOGLEVEL_QUIET = "4";
 
           MTD = "y";
-          MTD_CMDLINE_PARTS = "y";
           MTD_BLOCK = "y";          # fix undefined ref to register_mtd_blktrans_dev
 
           SPI = "y";
@@ -134,7 +160,6 @@
           REGULATOR_FIXED_VOLTAGE = "y";
 
           NET = "y";
-          NETDEVICES = "y";
           ETHERNET = "y";
 
           PHYLIB = "y";
@@ -151,10 +176,8 @@
 
           PHY_RALINK_USB = "y";
 
-          CMDLINE_PARTITION = "y";
           EARLY_PRINTK = "y";
 
-          PARTITION_ADVANCED = "y";
           PRINTK_TIME = "y";
         } // lib.optionalAttrs (config.system.service ? vlan) {
           SWCONFIG = "y";
@@ -162,6 +185,15 @@
           RALINK_WDT = "y";  # watchdog
           MT7621_WDT = "y";  # or it might be this one
         };
+        conditionalConfig = {
+          WLAN = {
+            WLAN_VENDOR_RALINK = "y";
+            WLAN_VENDOR_MEDIATEK = "y";
+            MT7603E = "m";
+          };
+        };
+
       };
+
     };
 }

devices/qemu-aarch64/default.nix

@@ -0,0 +1,51 @@
+# This "device" generates images that can be used with the QEMU
+# emulator. The default output is a directory containing separate
+# kernel ("Image" format) and root filesystem (squashfs or jffs2)
+# images
+{
+  system = {
+    crossSystem = {
+      config = "aarch64-unknown-linux-musl";
+    };
+  };
+
+  description = ''
+    QEMU Aarch64
+    ************
+
+    This target produces an image for
+    the `QEMU "virt" platform <https://www.qemu.org/docs/master/system/arm/virt.html>`_ using a 64 bit CPU type.
+
+    ARM targets differ from MIPS in that the kernel format expected
+    by QEMU is an "Image" (raw binary file) rather than an ELF
+    file, but this is taken care of by :command:`run.sh`. Check the
+    documentation for the :ref:`QEMU` (MIPS) target for more information.
+
+  '';
+
+  # this device is described by the "qemu" device
+  installer = "vmroot";
+
+  module = { config, lim, ... }: {
+    imports = [
+      ../../modules/arch/aarch64.nix
+      ../families/qemu.nix
+    ];
+    kernel = {
+      config = {
+        VIRTUALIZATION = "y";
+        PCI_HOST_GENERIC="y";
+
+        SERIAL_AMBA_PL011 = "y";
+        SERIAL_AMBA_PL011_CONSOLE = "y";
+      };
+    };
+    boot.commandLine = [
+      "console=ttyAMA0,38400"
+    ];
+    hardware = let addr = lim.parseInt "0x40010000"; in {
+      loadAddress = addr;
+      entryPoint = addr;
+    };
+  };
+}

devices/qemu-armv7l/default.nix

@@ -0,0 +1,53 @@
+# This "device" generates images that can be used with the QEMU
+# emulator. The default output is a directory containing separate
+# kernel ("Image" format) and root filesystem (squashfs or jffs2)
+# images
+{
+  system = {
+    crossSystem = {
+      config =  "armv7l-unknown-linux-musleabihf";
+    };
+  };
+
+  # this device is described by the "qemu" device
+  description = ''
+    QEMU ARM v7
+    ***********
+
+    This target produces an image for
+    the `QEMU "virt" platform <https://www.qemu.org/docs/master/system/arm/virt.html>`_ using a 32 bit CPU type.
+
+    ARM targets differ from MIPS in that the kernel format expected
+    by QEMU is an "Image" (raw binary file) rather than an ELF
+    file, but this is taken care of by :command:`run.sh`. Check the
+    documentation for the :ref:`QEMU` (MIPS) target for more information.
+  '';
+  installer = "vmroot";
+
+  module = { config, lim, ... }: {
+    imports = [
+      ../../modules/arch/arm.nix
+      ../families/qemu.nix
+    ];
+    kernel = {
+      config = {
+        PCI_HOST_GENERIC = "y";
+        ARCH_VIRT = "y";
+
+        VFP = "y";
+        NEON = "y";
+        AEABI = "y";
+
+        SERIAL_AMBA_PL011 = "y";
+        SERIAL_AMBA_PL011_CONSOLE = "y";
+      };
+    };
+    boot.commandLine = [
+      "console=ttyAMA0"
+    ];
+    hardware = let addr = lim.parseInt "0x40008000"; in {
+      loadAddress = addr;
+      entryPoint = addr;
+    };
+  };
+}

devices/qemu/default.nix

@@ -12,57 +12,65 @@
     };
   };
 
-  module = {pkgs, config, ... }: {
+  description = ''
+    QEMU MIPS
+    *********
+
+    This target produces an image for
+    QEMU, the "generic and open source machine emulator and
+    virtualizer".
+
+    MIPS QEMU emulates a "Malta" board, which was an ATX form factor
+    evaluation board made by MIPS Technologies, but mostly in Liminix
+    we use paravirtualized devices (Virtio) instead of emulating
+    hardware.
+
+    Building an image for QEMU results in a :file:`result/` directory
+    containing ``run.sh`` ``vmlinux``, and ``rootfs`` files. To invoke
+    the emulator, run ``run.sh``.
+
+    The configuration includes two emulated "hardware" ethernet
+    devices and the kernel :code:`mac80211_hwsim` module to
+    provide an emulated wlan device. To read more about how
+    to connect to this network, refer to :ref:`qemu-networking`
+    in the Development manual.
+
+  '';
+  module = { config, lib, lim, ... }: {
+    imports = [
+      ../../modules/arch/mipseb.nix
+      ../families/qemu.nix
+    ];
     kernel = {
-      src = pkgs.pkgsBuildBuild.fetchurl {
-        name = "linux.tar.gz";
-        url = "https://cdn.kernel.org/pub/linux/kernel/v5.x/linux-5.15.71.tar.gz";
-        hash = "sha256-yhO2cXIeIgUxkSZf/4aAsF11uxyh+UUZu6D1h92vCD8=";
-      };
       config = {
         MIPS_MALTA= "y";
-        CPU_LITTLE_ENDIAN= "n";
-        CPU_BIG_ENDIAN= "y";
         CPU_MIPS32_R2= "y";
 
-        MTD = "y";
-        MTD_BLOCK2MTD = "y";
-        MTD_BLKDEVS = "y";
-        MTD_BLOCK = "y";
-
-        VIRTIO_MENU = "y";
-        PCI = "y";
-        VIRTIO_PCI = "y";
-        BLOCK = "y";
-        VIRTIO_BLK = "y";
-        NETDEVICES = "y";
-        VIRTIO_NET = "y";
+        POWER_RESET = "y";
+        POWER_RESET_SYSCON = "y";
 
         SERIAL_8250= "y";
         SERIAL_8250_CONSOLE= "y";
       };
     };
     hardware =
-      let
-        mac80211 =  pkgs.mac80211.override {
-          drivers = ["mac80211_hwsim"];
-          klibBuild = config.system.outputs.kernel.modulesupport;
-        };
+      # from arch/mips/mti-malta/Platform:load-$(CONFIG_MIPS_MALTA)  += 0xffffffff80100000
+      let addr = lim.parseInt "0x80100000";
       in {
-        defaultOutput = "vmroot";
-        flash.eraseBlockSize = "65536"; # c.f. pkgs/mips-vm/mips-vm.sh
-        networkInterfaces =
-          let inherit (config.system.service.network) link;
-          in {
-            wan = link.build { ifname = "eth0"; };
-            lan = link.build { ifname = "eth1"; };
+        loadAddress = addr;
+        entryPoint = addr;
+
+        # Unlike the arm qemu targets, we need a static dts when
+        # running u-boot-using tests, qemu dumpdtb command doesn't
+        # work for this board. I am not at all sure this dts is
+        # *correct* but it does at least boot
+        dts = lib.mkForce {
+          src = "${config.system.outputs.kernel.modulesupport}/arch/mips/boot/dts/mti/malta.dts";
+          includes =  [
+            "${config.system.outputs.kernel.modulesupport}/arch/mips/boot/dts/"
+          ];
+        };
 
-            wlan_24 = link.build {
-              ifname = "wlan0";
-              dependencies = [ mac80211 ];
-            };
-          };
       };
-
   };
 }

devices/tp-archer-ax23/default.nix

@@ -0,0 +1,441 @@
+{
+  description = ''
+    TP-Link Archer AX23 / AX1800 Dual Band Wi-Fi 6 Router
+    *****************************************************
+
+    Hardware summary
+    ================
+
+    - MediaTek MT7621 (880MHz)
+    - 16MB Flash
+    - 128MB RAM
+    - WLan hardware: Mediatek MT7905, MT7975
+
+    Limitations
+    ===========
+
+    Status LEDs do not work yet.
+
+    Uploading an image via tftp doesn't work yet, because the Archer uboot
+    version is so old it doesn't support overriding the DTB from the mboot
+    command. The tftpboot module doesn't support this yet, see
+    https://gti.telent.net/dan/liminix/pulls/5 for the WiP.
+  '';
+
+  system = {
+    crossSystem = {
+      config = "mipsel-unknown-linux-musl";
+      gcc = {
+        abi = "32";
+        # https://openwrt.org/docs/techref/instructionset/mipsel_24kc
+        arch = "24kc";
+      };
+    };
+  };
+
+  module = {pkgs, config, lib, lim, ... }:
+    let firmware = pkgs.stdenv.mkDerivation {
+          name = "wlan-firmware";
+          phases = ["installPhase"];
+          installPhase = ''
+            mkdir $out
+            cp ${pkgs.linux-firmware}/lib/firmware/mediatek/{mt7915,mt7615,mt7622}* $out
+          '';
+        };
+    in {
+      imports = [
+        ../../modules/arch/mipsel.nix
+        ../../modules/outputs/tftpboot.nix
+        ../../modules/outputs/tplink-safeloader.nix
+      ];
+      config = {
+        kernel = {
+          src = pkgs.pkgsBuildBuild.fetchurl {
+            name = "linux.tar.gz";
+            url = "https://cdn.kernel.org/pub/linux/kernel/v5.x/linux-5.15.137.tar.gz";
+            hash = "sha256-PkdzUKZ0IpBiWe/RS70J76JKnBFzRblWcKlaIFNxnHQ=";
+          };
+          extraPatchPhase = ''
+            ${pkgs.openwrt.applyPatches.ramips}
+          '';
+          config = {
+            # Initially taken from openwrt's ./target/linux/ramips/mt7621/config-5.15,
+            # then tweaked here and there
+            ARCH_32BIT_OFF_T="y";
+            ARCH_HIBERNATION_POSSIBLE="y";
+            ARCH_KEEP_MEMBLOCK="y";
+            ARCH_MMAP_RND_BITS_MAX="15";
+            ARCH_MMAP_RND_COMPAT_BITS_MAX="15";
+            ARCH_SUSPEND_POSSIBLE="y";
+            AT803X_PHY="y";
+            BLK_MQ_PCI="y";
+            BOARD_SCACHE="y";
+            CEVT_R4K="y";
+            CLKSRC_MIPS_GIC="y";
+            CLK_MT7621="y";
+            CLOCKSOURCE_WATCHDOG="y";
+            CLONE_BACKWARDS="y";
+            CMDLINE_BOOL="y";
+            COMMON_CLK="y";
+            COMPAT_32BIT_TIME="y";
+            CPU_GENERIC_DUMP_TLB="y";
+            CPU_HAS_DIEI="y";
+            CPU_HAS_PREFETCH="y";
+            CPU_HAS_RIXI="y";
+            CPU_HAS_SYNC="y";
+            CPU_LITTLE_ENDIAN="y";
+            CPU_MIPS32="y";
+            CPU_MIPS32_R2="y";
+            CPU_MIPSR2="y";
+            CPU_MIPSR2_IRQ_EI="y";
+            CPU_MIPSR2_IRQ_VI="y";
+            CPU_NEEDS_NO_SMARTMIPS_OR_MICROMIPS="y";
+            CPU_R4K_CACHE_TLB="y";
+            CPU_RMAP="y";
+            CPU_SUPPORTS_32BIT_KERNEL="y";
+            CPU_SUPPORTS_HIGHMEM="y";
+            CPU_SUPPORTS_MSA="y";
+            CRC16="y";
+            CRYPTO_DEFLATE="y";
+            CRYPTO_HASH_INFO="y";
+            CRYPTO_LIB_BLAKE2S_GENERIC="y";
+            CRYPTO_LIB_POLY1305_RSIZE="2";
+            CRYPTO_LZO="y";
+            CRYPTO_ZSTD="y";
+            CSRC_R4K="y";
+            DIMLIB="y";
+            DMA_NONCOHERENT="y";
+            DTB_RT_NONE="y";
+            DTC="y";
+            EARLY_PRINTK="y";
+            FIXED_PHY="y";
+            FWNODE_MDIO="y";
+            FW_LOADER_PAGED_BUF="y";
+            GENERIC_ATOMIC64="y";
+            GENERIC_CLOCKEVENTS="y";
+            GENERIC_CMOS_UPDATE="y";
+            GENERIC_CPU_AUTOPROBE="y";
+            GENERIC_FIND_FIRST_BIT="y";
+            GENERIC_GETTIMEOFDAY="y";
+            GENERIC_IOMAP="y";
+            GENERIC_IRQ_CHIP="y";
+            GENERIC_IRQ_EFFECTIVE_AFF_MASK="y";
+            GENERIC_IRQ_SHOW="y";
+            GENERIC_LIB_ASHLDI3="y";
+            GENERIC_LIB_ASHRDI3="y";
+            GENERIC_LIB_CMPDI2="y";
+            GENERIC_LIB_LSHRDI3="y";
+            GENERIC_LIB_UCMPDI2="y";
+            GENERIC_PCI_IOMAP="y";
+            GENERIC_PHY="y";
+            GENERIC_PINCONF="y";
+            GENERIC_SCHED_CLOCK="y";
+            GENERIC_SMP_IDLE_THREAD="y";
+            GENERIC_TIME_VSYSCALL="y";
+            GLOB="y";
+            GPIOLIB_IRQCHIP="y";
+            GPIO_CDEV="y";
+            GPIO_GENERIC="y";
+            GPIO_MT7621="y";
+            GRO_CELLS="y";
+            HANDLE_DOMAIN_IRQ="y";
+            HARDWARE_WATCHPOINTS="y";
+            HAS_DMA="y";
+            HAS_IOMEM="y";
+            HAS_IOPORT_MAP="y";
+            I2C="y";
+            I2C_ALGOBIT="y";
+            I2C_BOARDINFO="y";
+            I2C_CHARDEV="y";
+            I2C_GPIO="y";
+            I2C_MT7621="y";
+            ICPLUS_PHY="y";
+            IRQCHIP="y";
+            IRQ_DOMAIN="y";
+            IRQ_DOMAIN_HIERARCHY="y";
+            IRQ_FORCED_THREADING="y";
+            IRQ_MIPS_CPU="y";
+            IRQ_WORK="y";
+            LIBFDT="y";
+            LOCK_DEBUGGING_SUPPORT="y";
+            LZO_COMPRESS="y";
+            LZO_DECOMPRESS="y";
+            MDIO_BUS="y";
+            MDIO_DEVICE="y";
+            MDIO_DEVRES="y";
+            MEDIATEK_GE_PHY="y";
+            MEMFD_CREATE="y";
+            MFD_SYSCON="y";
+            MIGRATION="y";
+            MIKROTIK="y";
+            MIKROTIK_RB_SYSFS="y";
+            MIPS="y";
+            MIPS_ASID_BITS="8";
+            MIPS_ASID_SHIFT="0";
+            MIPS_CLOCK_VSYSCALL="y";
+            MIPS_CM="y";
+            MIPS_CPC="y";
+            MIPS_CPS="y";
+            MIPS_CPU_SCACHE="y";
+            MIPS_GIC="y";
+            MIPS_L1_CACHE_SHIFT="5";
+            MIPS_LD_CAN_LINK_VDSO="y";
+            MIPS_MT="y";
+            MIPS_MT_FPAFF="y";
+            MIPS_MT_SMP="y";
+            MIPS_NR_CPU_NR_MAP="4";
+            MIPS_PERF_SHARED_TC_COUNTERS="y";
+            MIPS_SPRAM="y";
+            MODULES_USE_ELF_REL="y";
+            MTD_CMDLINE_PARTS="y";
+            MTD_NAND_CORE="y";
+            MTD_NAND_ECC="y";
+            MTD_NAND_ECC_SW_HAMMING="y";
+            MTD_NAND_MT7621="y";
+            MTD_NAND_MTK_BMT="y";
+            MTD_RAW_NAND="y";
+            MTD_ROUTERBOOT_PARTS="y";
+            MTD_SERCOMM_PARTS="y";
+            MTD_SPI_NOR="y";
+            MTD_SPLIT_FIT_FW="y";
+            MTD_SPLIT_MINOR_FW="y";
+            MTD_SPLIT_SEAMA_FW="y";
+            MTD_SPLIT_TPLINK_FW="y";
+            MTD_SPLIT_TRX_FW="y";
+            MTD_SPLIT_UIMAGE_FW="y";
+            MTD_UBI="y";
+            MTD_UBI_BEB_LIMIT="20";
+            MTD_UBI_BLOCK="y";
+            MTD_UBI_WL_THRESHOLD="4096";
+            MTD_VIRT_CONCAT="y";
+            NEED_DMA_MAP_STATE="y";
+            NET_DEVLINK="y";
+            NET_DSA="y";
+            NET_DSA_MT7530="y";
+            NET_DSA_MT7530_MDIO="y";
+            NET_DSA_TAG_MTK="y";
+            NET_FLOW_LIMIT="y";
+            NET_MEDIATEK_SOC="y";
+            NET_SELFTESTS="y";
+            NET_SWITCHDEV="y";
+            NET_VENDOR_MEDIATEK="y";
+            NO_HZ_COMMON="y";
+            NO_HZ_IDLE="y";
+            NR_CPUS="4";
+            NVMEM="y";
+            OF="y";
+            OF_ADDRESS="y";
+            OF_EARLY_FLATTREE="y";
+            OF_FLATTREE="y";
+            OF_GPIO="y";
+            OF_IRQ="y";
+            OF_KOBJ="y";
+            OF_MDIO="y";
+            PAGE_POOL="y";
+            PAGE_POOL_STATS="y";
+            PCI="y";
+            PCIE_MT7621="y";
+            PCI_DISABLE_COMMON_QUIRKS="y";
+            PCI_DOMAINS="y";
+            PCI_DOMAINS_GENERIC="y";
+            PCI_DRIVERS_GENERIC="y";
+            PCS_MTK_LYNXI="y";
+            PERF_USE_VMALLOC="y";
+            PGTABLE_LEVELS="2";
+            PHYLIB="y";
+            PHYLINK="y";
+            PHY_MT7621_PCI="y";
+            PINCTRL="y";
+            PINCTRL_AW9523="y";
+            PINCTRL_MT7621="y";
+            PINCTRL_RALINK="y";
+            PINCTRL_SX150X="y";
+            POWER_RESET="y";
+            POWER_RESET_GPIO="y";
+            POWER_SUPPLY="y";
+            PTP_1588_CLOCK_OPTIONAL="y";
+            QUEUED_RWLOCKS="y";
+            QUEUED_SPINLOCKS="y";
+            RALINK="y";
+            RATIONAL="y";
+            REGMAP="y";
+            REGMAP_I2C="y";
+            REGMAP_MMIO="y";
+            REGULATOR="y";
+            REGULATOR_FIXED_VOLTAGE="y";
+            RESET_CONTROLLER="y";
+            RFS_ACCEL="y";
+            RPS="y";
+            RTC_CLASS="y";
+            RTC_DRV_BQ32K="y";
+            RTC_DRV_PCF8563="y";
+            RTC_I2C_AND_SPI="y";
+            SCHED_SMT="y";
+            SERIAL_8250="y";
+            SERIAL_8250_CONSOLE="y";
+            SERIAL_8250_NR_UARTS="3";
+            SERIAL_8250_RUNTIME_UARTS="3";
+            SERIAL_MCTRL_GPIO="y";
+            SERIAL_OF_PLATFORM="y";
+            SGL_ALLOC="y";
+            SMP="y";
+            SMP_UP="y";
+            SOCK_RX_QUEUE_MAPPING="y";
+            SOC_BUS="y";
+            SOC_MT7621="y";
+            SPI="y";
+            SPI_MASTER="y";
+            SPI_MEM="y";
+            SPI_MT7621="y";
+            SRCU="y";
+            SWPHY="y";
+            SYNC_R4K="y";
+            SYSCTL_EXCEPTION_TRACE="y";
+            SYS_HAS_CPU_MIPS32_R1="y";
+            SYS_HAS_CPU_MIPS32_R2="y";
+            SYS_HAS_EARLY_PRINTK="y";
+            SYS_SUPPORTS_32BIT_KERNEL="y";
+            SYS_SUPPORTS_ARBIT_HZ="y";
+            SYS_SUPPORTS_HIGHMEM="y";
+            SYS_SUPPORTS_HOTPLUG_CPU="y";
+            SYS_SUPPORTS_LITTLE_ENDIAN="y";
+            SYS_SUPPORTS_MIPS16="y";
+            SYS_SUPPORTS_MIPS_CPS="y";
+            SYS_SUPPORTS_MULTITHREADING="y";
+            SYS_SUPPORTS_SCHED_SMT="y";
+            SYS_SUPPORTS_SMP="y";
+            SYS_SUPPORTS_ZBOOT="y";
+            TARGET_ISA_REV="2";
+            TICK_CPU_ACCOUNTING="y";
+            TIMER_OF="y";
+            TIMER_PROBE="y";
+            TREE_RCU="y";
+            TREE_SRCU="y";
+            UBIFS_FS="y";
+            USB_SUPPORT="y";
+            USE_OF="y";
+            WEAK_ORDERING="y";
+            XPS="y";
+            XXHASH="y";
+            ZLIB_DEFLATE="y";
+            ZLIB_INFLATE="y";
+            ZSTD_COMPRESS="y";
+            ZSTD_DECOMPRESS="y";
+          } // lib.optionalAttrs (config.system.service ? watchdog) {
+            RALINK_WDT = "y";  # watchdog
+            MT7621_WDT = "y";  # or it might be this one
+          };
+          conditionalConfig = {
+            WLAN = {
+              MT7915E = "m";
+            };
+          };
+        };
+        tplink-safeloader.board = "ARCHER-AX23-V1";
+        boot = {
+          commandLine = [ "console=ttyS0,115200" ];
+          tftp = {
+            # Should be a segment of free RAM, where the tftp artifact
+            # can be stored before unpacking it to the 'hardware.loadAddress'
+            # The 'hardware.loadAddress' is 0x80001000, which suggests the
+            # RAM would start at 0x8000000 and (being 128MB) go to
+            # to 0x8800000. Let's put it at the 100MB mark at
+            # 0x8000000+0x0640000=0x86400000
+            loadAddress = lim.parseInt "0x86400000";
+          };
+        };
+        filesystem =
+        let inherit (pkgs.pseudofile) dir symlink;
+             in
+               dir {
+                 lib = dir {
+                   firmware = dir {
+                     mediatek = symlink firmware;
+                   };
+                 };
+               };
+
+      hardware =
+        let
+          openwrt = pkgs.openwrt;
+          mac80211 =  pkgs.kmodloader.override {
+            targets = [
+              "mt7915e"
+            ];
+            inherit (config.system.outputs) kernel;
+          };
+        in {
+          # from OEM bootlog (openwrt wiki):
+          # 4 cmdlinepart partitions found on MTD device raspi
+          # Creating 4 MTD partitions on "raspi":
+          # 0x000000000000-0x000000040000 : "uboot"
+          # 0x000000040000-0x000000440000 : "uImage"
+          # 0x000000440000-0x000000ff0000 : "rootfs"
+          # 0x000000ff0000-0x000001000000 : "ART"
+          # from openwrt bootlog (openwrt wiki):
+          # 5 fixed-partitions partitions found on MTD device spi0.0
+          # OF: Bad cell count for /palmbus@1e000000/spi@b00/flash@0/partitions
+          # OF: Bad cell count for /palmbus@1e000000/spi@b00/flash@0/partitions
+          # OF: Bad cell count for /palmbus@1e000000/spi@b00/flash@0/partitions
+          # OF: Bad cell count for /palmbus@1e000000/spi@b00/flash@0/partitions
+          # Creating 5 MTD partitions on "spi0.0":
+          # 0x000000000000-0x000000040000 : "u-boot"
+          # 0x000000040000-0x000000fa0000 : "firmware"
+          # 2 uimage-fw partitions found on MTD device firmware
+          # Creating 2 MTD partitions on "firmware":
+          # 0x000000000000-0x0000002c0000 : "kernel"
+          # 0x0000002c0000-0x000000f60000 : "rootfs"
+          # mtd: setting mtd3 (rootfs) as root device
+          # 1 squashfs-split partitions found on MTD device rootfs
+          # 0x000000640000-0x000000f60000 : "rootfs_data"
+          # 0x000000fa0000-0x000000fb0000 : "config"
+          # 0x000000fb0000-0x000000ff0000 : "tplink"
+          # 0x000000ff0000-0x000001000000 : "radio"
+          flash = {
+            # from the OEM bootlog 'Booting image at bc040000'
+            # (0x40000 from 0xbc000000)
+            address = lim.parseInt "0xbc040000";
+            # 0x000000040000-0x000000fa0000
+            size = lim.parseInt "0xf60000";
+            # TODO: find in /proc/mtd on a running system
+            eraseBlockSize = 65536;
+          };
+
+          # since this is mentioned in the partition table as well?
+          defaultOutput = "tplink-safeloader";
+          # taken from openwrt sysupgrade image:
+          # openwrt-23.05.2-ramips-mt7621-tplink_archer-ax23-v1-squashfs-sysupgrade.bin: u-boot legacy uImage, MIPS OpenWrt Linux-5.15.137, Linux/MIPS, OS Kernel Image (lzma), 2797386 bytes, Tue Nov 14 13:38:11 2023, Load Address: 0X80001000, Entry Point: 0X80001000, Header CRC: 0X19F74C5B, Data CRC: 0XF685563C
+          loadAddress = lim.parseInt "0x80001000";
+          entryPoint = lim.parseInt "0x80001000";
+          rootDevice = "/dev/mtdblock3";
+          dts = {
+            src = "${openwrt.src}/target/linux/ramips/dts/mt7621_tplink_archer-ax23-v1.dts";
+            includes =  [
+              "${openwrt.src}/target/linux/ramips/dts"
+              "${config.system.outputs.kernel.modulesupport}/arch/arm64/boot/dts/mediatek/"
+            ];
+          };
+
+          networkInterfaces =
+            let
+              inherit (config.system.service.network) link;
+            in rec {
+              lan1 = link.build { ifname = "lan1"; };
+              lan2 = link.build { ifname = "lan2"; };
+              lan3 = link.build { ifname = "lan3"; };
+              lan4 = link.build { ifname = "lan4"; };
+              wan = link.build { ifname = "wan"; };
+
+              wlan = link.build {
+                ifname = "wlan0";
+                dependencies = [ mac80211 ];
+              };
+              wlan5 = link.build {
+                ifname = "wlan1";
+                dependencies = [ mac80211 ];
+              };
+            };
+        };
+    };
+    };
+}

devices/turris-omnia/default.nix

@@ -0,0 +1,409 @@
+{
+  description = ''
+    Turris Omnia
+    ************
+
+    This is a 32 bit ARMv7 MVEBU device, which is usually shipped with
+    TurrisOS, an OpenWrt-based system. Rather than reformatting the
+    builtin storage, we install Liminix on to the existing btrfs
+    filesystem so that the vendor snapshot/recovery system continues
+    to work (and provides you an easy rollback if you decide you don't
+    like Liminix after all).
+
+    The install process has two stages, and is intended that you
+    should not need to open the device and add a serial console
+    (although it may be handy for visibility, and in case anything
+    goes wrong). First we build a minimal installation/recovery
+    system, then we reboot into that recovery image to prepare the
+    device for the full target install.
+
+    Installation using a USB stick
+    ==============================
+
+    First, build the image for the USB stick. Review
+    :file:`examples/recovery.nix` in order to change the default
+    root password (which is ``secret``) and/or the SSH keys, then
+    build it with
+
+    .. code-block:: console
+
+        $ nix-build -I liminix-config=./examples/recovery.nix \
+          --arg device "import ./devices/turris-omnia" \
+          -A outputs.mbrimage -o mbrimage
+        $ file -L mbrimage
+        mbrimage: DOS/MBR boot sector; partition 1 : ID=0x83, active, start-CHS (0x0,0,5), end-CHS (0x6,130,26), startsector 4, 104602 sectors
+
+    Next, copy the image from your build machine to a USB storage
+    medium using :command:`dd` or your other most favoured file copying
+    tool, which might be a comand something like this:
+
+    .. code-block:: console
+
+        $ dd if=mbrimage of=/dev/path/to/the/usb/stick \
+          bs=1M conv=fdatasync status=progress
+
+    The Omnia's default boot order only checks USB after it has failed
+    to boot from eMMC, which is not ideal for our purpose.  Unless you
+    have a serial cable, the easiest way to change this is by booting
+    to TurrisOS and logging in with ssh:
+
+    .. code-block:: console
+
+        root@turris:/# fw_printenv boot_targets
+        boot_targets=mmc0 nvme0 scsi0 usb0 pxe dhcp
+        root@turris:/# fw_setenv boot_targets usb0 mmc0
+        root@turris:/# fw_printenv boot_targets
+        boot_targets=usb0 mmc0
+        root@turris:/# reboot -f
+
+    It should now boot into the recovery image. It expects a network
+    cable to be plugged into LAN2 with something on the other end of
+    it that serves DHCP requests.  Check your DHCP server logs for a
+    request from a ``liminix-recovery`` host and figure out what IP
+    address was assigned.
+
+    .. code-block:: console
+
+        $ ssh liminix-recovery.lan
+
+    You should get a "Busybox" banner and a root prompt. Now you can
+    start preparing the device to install Liminix on it. First we'll
+    mount the root filesystem and take a snapshot:
+
+    .. code-block:: console
+
+        # mkdir /dest && mount /dev/mmcblk0p1 /dest
+        # schnapps -d /dest create "pre liminix"
+        # schnapps -d /dest list
+        ERROR: not a valid btrfs filesystem: /
+            # | Type      | Size        | Date                      | Description
+        ------+-----------+-------------+---------------------------+------------------------------------
+            1 | single    |    16.00KiB | 1970-01-01 00:11:49 +0000 | pre liminix
+
+    (``not a valid btrfs filesystem: /`` is not a real error)
+
+    then we can remove all the files
+
+    .. code-block:: console
+
+        # rm -r /dest/@/*
+
+    and then it's ready to install the real Liminix system onto. On
+    your build system, create the Liminix configuration you wish to
+    install: here we'll use the ``rotuer`` example.
+
+    .. code-block:: console
+
+        build$ nix-build -I liminix-config=./examples/rotuer.nix \
+          --arg device "import ./devices/turris-omnia" \
+          -A outputs.systemConfiguration
+
+    and then use :command:`min-copy-closure` to copy it to the device.
+
+    .. code-block:: console
+
+        build$ nix-shell --run \
+          "min-copy-closure -r /dest/@  root@liminix-recovery.lan result"
+
+    and activate it
+
+    .. code-block:: console
+
+        build$ ssh root@liminix-recovery.lan \
+          "/dest/@/$(readlink result)/bin/install /dest/@"
+
+    The final steps are performed directly on the device again: add
+    a symlink so U-Boot can find :file:`/boot`, then restore the
+    default boot order and reboot into the new configuration.
+
+    .. code-block:: console
+
+        # cd /dest && ln -s @/boot .
+        # fw_setenv boot_targets "mmc0 nvme0 scsi0 usb0 pxe dhcp"
+        # cd / ; umount /dest
+        # reboot
+
+
+    Installation using a TFTP server and serial console
+    ===================================================
+
+    If you have a :ref:`serial` console connection and a TFTP server,
+    and would rather use them than fiddling with USB sticks, the
+    :file:`examples/recovery.nix` configuration also works
+    using the ``tftpboot`` output. So you can do
+
+    .. code-block:: console
+
+        build$ nix-build -I liminix-config=./examples/recovery.nix \
+          --arg device "import ./devices/turris-omnia" \
+          -A outputs.tftpboot
+
+    and then paste the generated :file:`result/boot.scr` into
+    U-Boot, and you will end up with the same system as you would
+    have had after booting from USB. If you don't have a serial
+    console connection you could probably even get clever with
+    elaborate use of :command:`fw_setenv`, but that is left as
+    an exercise for the reader.
+
+  '';
+
+  system = {
+    crossSystem = {
+      config = "armv7l-unknown-linux-musleabihf";
+    };
+  };
+
+  module = {pkgs, config, lib, lim, ... }:
+    let
+      inherit (pkgs.liminix.services) oneshot;
+      inherit (pkgs) liminix;
+      mtd_by_name_links = pkgs.liminix.services.oneshot rec  {
+        name = "mtd_by_name_links";
+        up = ''
+          mkdir -p /dev/mtd/by-name
+          cd /dev/mtd/by-name
+          for i in /sys/class/mtd/mtd*[0-9]; do
+            ln -s ../../$(basename $i) $(cat $i/name)
+          done
+        '';
+      };
+    in {
+      imports = [
+        ../../modules/arch/arm.nix
+        ../../modules/outputs/tftpboot.nix
+        ../../modules/outputs/mbrimage.nix
+        ../../modules/outputs/extlinux.nix
+      ];
+
+      config = {
+        services.mtd-name-links = mtd_by_name_links;
+        kernel = {
+          src = pkgs.pkgsBuildBuild.fetchurl {
+            name = "linux.tar.gz";
+            url = "https://cdn.kernel.org/pub/linux/kernel/v6.x/linux-6.7.4.tar.gz";
+            hash = "sha256-wIrmL0BS63nRwWfm4nw+dRNVPUzGh9M4X7LaHzAn5tU=";
+          };
+          version = "6.7.4";
+          config = {
+            PCI = "y";
+            OF = "y";
+            MEMORY = "y"; # for MVEBU_DEVBUS
+            DMADEVICES = "y"; # for MV_XOR
+            CPU_V7 = "y";
+            ARCH_MULTIPLATFORM = "y";
+            ARCH_MVEBU = "y";
+            ARCH_MULTI_V7= "y";
+            PCI_MVEBU = "y";
+            AHCI_MVEBU = "y";
+
+            RTC_CLASS = "y";
+            RTC_DRV_ARMADA38X = "y"; # this may be useful anyway?
+
+            EXPERT = "y";
+            ALLOW_DEV_COREDUMP = "n";
+
+
+            # dts has a compatible for this but dmesg is not
+            # showing it
+            EEPROM_AT24 = "y"; # atmel,24c64
+
+            I2C = "y";
+            I2C_MUX = "y";
+            I2C_MUX_PCA954x = "y";
+
+            MACH_ARMADA_38X = "y";
+            SMP = "y";
+	          # this is disabled for the moment because it relies on a
+            # GCC plugin that requires gmp.h to build, and I can't see
+            # right now how to confgure it to find gmp
+            STACKPROTECTOR_PER_TASK = "n";
+            NR_CPUS = "4";
+            VFP = "y";
+            NEON= "y";
+
+            # WARNING: unmet direct dependencies detected for ARCH_WANT_LIBATA_LEDS
+            ATA = "y";
+
+            PSTORE = "y";
+            PSTORE_RAM = "y";
+            PSTORE_CONSOLE = "y";
+#            PSTORE_DEFLATE_COMPRESS = "n";
+
+            BLOCK = "y";
+            MMC="y";
+            PWRSEQ_EMMC="y";        # ???
+            PWRSEQ_SIMPLE="y";      # ???
+            MMC_BLOCK="y";
+
+            MMC_SDHCI= "y";
+            MMC_SDHCI_PLTFM= "y";
+            MMC_SDHCI_PXAV3= "y";
+            MMC_MVSDIO= "y";
+
+            SERIAL_8250 = "y";
+            SERIAL_8250_CONSOLE = "y";
+            SERIAL_OF_PLATFORM="y";
+            SERIAL_MVEBU_UART = "y";
+            SERIAL_MVEBU_CONSOLE = "y";
+
+            SERIAL_8250_DMA= "y";
+            SERIAL_8250_DW= "y";
+            SERIAL_8250_EXTENDED= "y";
+            SERIAL_8250_MANY_PORTS= "y";
+            SERIAL_8250_SHARE_IRQ= "y";
+            OF_ADDRESS= "y";
+            OF_MDIO= "y";
+
+            WATCHDOG = "y";        # watchdog is enabled by u-boot
+            ORION_WATCHDOG = "y";  # so is non-optional to keep feeding
+
+            MVEBU_DEVBUS = "y"; # "Device Bus controller ...  flash devices such as NOR, NAND, SRAM, and FPGA"
+            MVMDIO = "y";
+            MVNETA = "y";
+            MVNETA_BM = "y";
+            MVNETA_BM_ENABLE = "y";
+            SRAM = "y"; # mmio-sram is "compatible" for bm_bppi reqd by BM
+            PHY_MVEBU_A38X_COMPHY = "y"; # for eth2
+            MARVELL_PHY = "y";
+
+            MVPP2 = "y";
+            MV_XOR = "y";
+
+            # there is NOR flash on this device, which is used for U-Boot
+            # and the rescue system (which we don't interfere with) but
+            # also for the U-Boot environment variables (which we might
+            # need to meddle with)
+            MTD_SPI_NOR = "y";
+            SPI = "y";
+            SPI_MASTER = "y";
+            SPI_ORION = "y";
+
+            NET_DSA = "y";
+            NET_DSA_MV88E6XXX = "y"; # depends on PTP_1588_CLOCK_OPTIONAL
+          };
+          conditionalConfig = {
+            USB = {
+              USB_XHCI_MVEBU = "y";
+              USB_XHCI_HCD = "y";
+            };
+            WLAN = {
+              WLAN_VENDOR_ATH = "y";
+              ATH_COMMON = "m";
+              ATH9K = "m";
+              ATH9K_PCI = "y";
+              ATH10K = "m";
+              ATH10K_PCI = "m";
+              ATH10K_DEBUG = "y";
+            };
+          };
+        };
+        boot = {
+          commandLine = [
+            "console=ttyS0,115200"
+            "pcie_aspm=off" # ath9k pci incompatible with PCIe ASPM
+          ];
+        };
+        filesystem =
+          let
+            inherit (pkgs.pseudofile) dir symlink;
+            firmware = pkgs.stdenv.mkDerivation {
+              name = "wlan-firmware";
+              phases = ["installPhase"];
+              installPhase = ''
+                mkdir $out
+                cp -r ${pkgs.linux-firmware}/lib/firmware/ath10k/QCA988X $out
+              '';
+            };
+          in dir {
+            lib = dir {
+              firmware = dir {
+                ath10k = symlink firmware;
+              };
+            };
+            etc = dir {
+              "fw_env.config" =
+                let f = pkgs.writeText "fw_env.config" ''
+                  /dev/mtd/by-name/u-boot-env 0x0 0x10000 0x10000
+                '';
+                in symlink f;
+            };
+          };
+
+        boot.tftp = {
+          loadAddress = lim.parseInt "0x1700000";
+          kernelFormat = "zimage";
+          compressRoot = true;
+        };
+
+        hardware = let
+          mac80211 =  pkgs.kmodloader.override {
+            inherit (config.system.outputs) kernel;
+            targets = ["ath9k" "ath10k_pci"];
+          };
+        in {
+          defaultOutput = "mtdimage";
+          loadAddress = lim.parseInt "0x00800000"; # "0x00008000";
+          entryPoint = lim.parseInt "0x00800000"; # "0x00008000";
+          rootDevice = "/dev/mmcblk0p1";
+
+          dts = {
+            src = "${config.system.outputs.kernel.modulesupport}/arch/arm/boot/dts/marvell/armada-385-turris-omnia.dts";
+            includes =  [
+              "${config.system.outputs.kernel.modulesupport}/arch/arm/boot/dts/marvell/"
+            ];
+          };
+          flash.eraseBlockSize = 65536; # only used for tftpboot
+          networkInterfaces =
+            let
+              inherit (config.system.service.network) link;
+            in rec {
+              en70000 = link.build {
+                # in armada-38x.dtsi this is eth0.
+                # It's connected to port 5 of the 88E6176 switch
+                devpath = "/devices/platform/soc/soc:internal-regs/f1070000.ethernet";
+                # name is unambiguous but not very semantic
+                ifname = "en70000";
+              };
+              en30000 = link.build {
+                # in armada-38x.dtsi this is eth1
+                # It's connected to port 6 of the 88E6176 switch
+                devpath = "/devices/platform/soc/soc:internal-regs/f1030000.ethernet";
+                # name is unambiguous but not very semantic
+                ifname = "en30000";
+              };
+              # the default (from the dts? I'm guessing) behavour for
+              # lan ports on the switch is to attach them to
+              # en30000. It should be possible to do something better,
+              # per
+              # https://www.kernel.org/doc/html/latest/networking/dsa/configuration.html#affinity-of-user-ports-to-cpu-ports
+              # but apparently OpenWrt doesn't either so maybe it's more
+              # complicated than it looks.
+
+              wan = link.build {
+                # in armada-38x.dtsi this is eth2. It may be connected to
+                # an ethernet phy or to the SFP cage, depending on a gpio
+                devpath = "/devices/platform/soc/soc:internal-regs/f1034000.ethernet";
+                ifname = "wan";
+              };
+
+              lan0 = link.build { ifname = "lan0"; };
+              lan1 = link.build { ifname = "lan1"; };
+              lan2 = link.build { ifname = "lan2"; };
+              lan3 = link.build { ifname = "lan3"; };
+              lan4 = link.build { ifname = "lan4"; };
+              lan5 = link.build { ifname = "lan5"; };
+              lan = lan0; # maybe we should build a bridge?
+
+              wlan = link.build {
+                ifname = "wlan0";
+                dependencies = [ mac80211 ];
+              };
+              wlan5 = link.build {
+                ifname = "wlan1";
+                dependencies = [ mac80211 ];
+              };
+            };
+        };
+      };
+    };
+}

devices/zyxel-nwa50ax/a_image/mt7621_zyxel_nwa-ax-for-ab.dtsi

@@ -0,0 +1,155 @@
+#include "mt7621.dtsi"
+
+#include <dt-bindings/gpio/gpio.h>
+#include <dt-bindings/input/input.h>
+
+/ {
+	aliases {
+		label-mac-device = &gmac0;
+	};
+};
+
+&nand {
+	status = "okay";
+
+	mediatek,nmbm;
+	mediatek,bmt-max-ratio = <15>;
+	mediatek,bmt-max-reserved-blocks = <64>;
+	mediatek,bmt-remap-range =
+		<0x0 0x980000>,
+		<0x2980000 0x7800000>;
+
+	partitions {
+		compatible = "fixed-partitions";
+		#address-cells = <1>;
+		#size-cells = <1>;
+
+		partition@0 {
+			label = "u-boot";
+			reg = <0x0 0x80000>;
+			read-only;
+		};
+
+		partition@80000 {
+			label = "u-boot-env";
+			reg = <0x80000 0x80000>;
+			read-only;
+		};
+
+		factory: partition@100000 {
+			label = "factory";
+			reg = <0x100000 0x80000>;
+			read-only;
+		};
+
+		partition@180000 {
+			label = "firmware_a";
+			reg = <0x180000 0x2800000>;
+
+			compatible = "fixed-partitions";
+			#address-cells = <1>;
+			#size-cells = <1>;
+
+			partition@0 {
+				label = "kernel_a";
+				reg = <0x0 0x800000>;
+			};
+
+			partition@400000 {
+				label = "ubi";
+				reg = <0x800000 0x2000000>;
+			};
+		};
+
+		partition@2980000 {
+			label = "firmware_b";
+			reg = <0x2980000 0x2800000>;
+
+			compatible = "fixed-partitions";
+			#address-cells = <1>;
+			#size-cells = <1>;
+
+			partition@0 {
+				label = "kernel_b";
+				reg = <0x0 0x800000>;
+			};
+
+			partition@400000 {
+				label = "ubi_b";
+				reg = <0x800000 0x2000000>;
+			};
+		};
+
+		partition@5180000 {
+			label = "rootfs_data";
+			reg = <0x5180000 0x1400000>;
+		};
+
+		partition@6580000 {
+			label = "logs";
+			reg = <0x6580000 0xd00000>;
+		};
+
+		partition@7280000 {
+			label = "vendor-myzyxel";
+			reg = <0x7280000 0x480000>;
+			read-only;
+		};
+
+		partition@7700000 {
+			label = "bootconfig";
+			reg = <0x7700000 0x80000>;
+		};
+
+		mrd: partition@7780000 {
+			label = "mrd";
+			reg = <0x7780000 0x80000>;
+			read-only;
+
+			nvmem-layout {
+				compatible = "fixed-layout";
+				#address-cells = <1>;
+				#size-cells = <1>;
+
+				macaddr_mrd_1fff8: macaddr@1fff8 {
+					reg = <0x1fff8 0x6>;
+				};
+			};
+		};
+	};
+};
+
+&pcie {
+	status = "okay";
+};
+
+&pcie1 {
+	wlan_5g: wifi@0,0 {
+		reg = <0x0 0 0 0 0>;
+		compatible = "mediatek,mt76";
+
+		mediatek,mtd-eeprom = <&factory 0x0>;
+		/* MAC-Address set in userspace */
+	};
+};
+
+&gmac0 {
+	nvmem-cells = <&macaddr_mrd_1fff8>;
+	nvmem-cell-names = "mac-address";
+};
+
+&switch0 {
+	ports {
+		port@4 {
+			status = "okay";
+			label = "lan";
+		};
+	};
+};
+
+&state_default {
+	gpio {
+		groups = "uart3";
+		function = "gpio";
+	};
+};

devices/zyxel-nwa50ax/b_image/mt7621_zyxel_nwa-ax-for-ab.dtsi

@@ -0,0 +1,155 @@
+#include "mt7621.dtsi"
+
+#include <dt-bindings/gpio/gpio.h>
+#include <dt-bindings/input/input.h>
+
+/ {
+	aliases {
+		label-mac-device = &gmac0;
+	};
+};
+
+&nand {
+	status = "okay";
+
+	mediatek,nmbm;
+	mediatek,bmt-max-ratio = <15>;
+	mediatek,bmt-max-reserved-blocks = <64>;
+	mediatek,bmt-remap-range =
+		<0x0 0x980000>,
+		<0x2980000 0x7800000>;
+
+	partitions {
+		compatible = "fixed-partitions";
+		#address-cells = <1>;
+		#size-cells = <1>;
+
+		partition@0 {
+			label = "u-boot";
+			reg = <0x0 0x80000>;
+			read-only;
+		};
+
+		partition@80000 {
+			label = "u-boot-env";
+			reg = <0x80000 0x80000>;
+			read-only;
+		};
+
+		factory: partition@100000 {
+			label = "factory";
+			reg = <0x100000 0x80000>;
+			read-only;
+		};
+
+		partition@2980000 {
+			label = "firmware_b";
+			reg = <0x2980000 0x2800000>;
+
+			compatible = "fixed-partitions";
+			#address-cells = <1>;
+			#size-cells = <1>;
+
+			partition@0 {
+				label = "kernel_b";
+				reg = <0x0 0x800000>;
+			};
+
+			partition@400000 {
+				label = "ubi";
+				reg = <0x800000 0x2000000>;
+			};
+		};
+
+		partition@180000 {
+			label = "firmware_a";
+			reg = <0x180000 0x2800000>;
+
+			compatible = "fixed-partitions";
+			#address-cells = <1>;
+			#size-cells = <1>;
+
+			partition@0 {
+				label = "kernel_a";
+				reg = <0x0 0x800000>;
+			};
+
+			partition@400000 {
+				label = "ubi_a";
+				reg = <0x800000 0x2000000>;
+			};
+		};
+
+		partition@5180000 {
+			label = "rootfs_data";
+			reg = <0x5180000 0x1400000>;
+		};
+
+		partition@6580000 {
+			label = "logs";
+			reg = <0x6580000 0xd00000>;
+		};
+
+		partition@7280000 {
+			label = "vendor-myzyxel";
+			reg = <0x7280000 0x480000>;
+			read-only;
+		};
+
+		partition@7700000 {
+			label = "bootconfig";
+			reg = <0x7700000 0x80000>;
+		};
+
+		mrd: partition@7780000 {
+			label = "mrd";
+			reg = <0x7780000 0x80000>;
+			read-only;
+
+			nvmem-layout {
+				compatible = "fixed-layout";
+				#address-cells = <1>;
+				#size-cells = <1>;
+
+				macaddr_mrd_1fff8: macaddr@1fff8 {
+					reg = <0x1fff8 0x6>;
+				};
+			};
+		};
+	};
+};
+
+&pcie {
+	status = "okay";
+};
+
+&pcie1 {
+	wlan_5g: wifi@0,0 {
+		reg = <0x0 0 0 0 0>;
+		compatible = "mediatek,mt76";
+
+		mediatek,mtd-eeprom = <&factory 0x0>;
+		/* MAC-Address set in userspace */
+	};
+};
+
+&gmac0 {
+	nvmem-cells = <&macaddr_mrd_1fff8>;
+	nvmem-cell-names = "mac-address";
+};
+
+&switch0 {
+	ports {
+		port@4 {
+			status = "okay";
+			label = "lan";
+		};
+	};
+};
+
+&state_default {
+	gpio {
+		groups = "uart3";
+		function = "gpio";
+	};
+};

devices/zyxel-nwa50ax/default.nix

@@ -0,0 +1,365 @@
+{
+  system = {
+    crossSystem = {
+      config = "mipsel-unknown-linux-musl";
+      gcc = {
+        abi = "32";
+        arch = "mips32";          # mips32r2?
+      };
+    };
+  };
+
+  description = ''
+    Zyxel NWA50AX
+    ********************
+
+    Zyxel NWA50AX is quite close to the GL-MT300N-v2 "Mango" device, but it is based on the MT7621
+    chipset instead of the MT7628.
+
+    Installation
+    ============
+
+    This device is pretty, but, due to its A/B capabilities, can be a bit hard
+    to use completely.
+
+    The stock vendor firmware is a downstream fork of U-Boot: <https://github.com/RaitoBezarius/uboot-nwa50ax>
+    with restricted boot commands. Fortunately, OpenWrt folks figured out trivial command injections,
+    so you can use most of the OpenWrt commands without trouble by just command injecting
+    atns, atna or atnf, e.g. atns "; $real_command".
+
+    From factory web UI, you can upload the result of the zyxel-nwa-fit output.
+    From another operating system, you need to `dumpimage -T flat_dt -p 0 $zyxel-nwa-fit -o firmware.bin`,
+    `flash_erase $(mtd partition of the target partition firmware or zy_firmware) 0 0`, then you complete by
+    `nandwrite -p $(mtd partition of the target partition firmware or zy_firmware) firmware.bin`.
+
+    How to put the firmware.bin on the machine is left to you as an exercise, e.g. SSH, TFTP, whatever.
+
+    From serial, you have two choices:
+
+    - Flash this system via U-Boot:
+      same reasoning as from an existing Linux system, two choices:
+      - ymodem the binary, perform the write manually, you can inspire yourself
+      from the `script` contained in the vendor firmware, those are just a FIT containing a script.
+      - prepare a FIT containing a script executing your commands, tftpboot this.
+
+    - boot from an existing Liminix system, e.g. TFTPBOOT image.
+    - boot from an OpenWrt system, i.e. follow OpenWrt steps.
+
+    Once you are in a Linux system, understand that this device has A/B boot.
+
+    OpenWrt provides you with `zyxel-bootconfig` to set/unset the image status and choice.
+
+    The kernel is booted with `bootImage=<number>` which tells you which slot are you on.
+
+    You should find yourself with 10ish MTD partitions, the most interesting ones are two:
+
+    - firmware: 40MB
+    - firmware_1: 40MB
+
+    In the current setup, they are split further into kernel (8MB) and ubi (32MB).
+
+    Once you are done with first installation, note that if you want to use the A/B feature,
+    you need to write a _secondary_ image on the slot B. There is no proper flashing code
+    that will set the being-updated slot to `new` and boot on it to verify if it's working.
+    This is a WIP.
+
+    Upgrading your system can be achieved via:
+
+    - `liminix-rebuild` for the userspace.
+    - `flash_erase` + `nandwrite` for the kernelspace to the other slot than the one you are booted on,
+      note that you can just nandwrite the mtd partition corresponding to the *kernel* and not the whole firmware.
+
+    If you soft-bricked your AP, i.e. you cannot boot anything in U-Boot, no worries, just plug the serial console,
+    prepare a TFTP server (via `tufted` for example), download vendor firmware, set up `atns`, `atnf`, etc. and run `atnz`.
+
+    This will reflash everything back to normal via TFTP.
+
+    If you hard-bricked your AP, i.e. U-Boot is telling you to transfer a valid bootloader via ymodem, just extract
+    a U-Boot from the vendor OS, send it via ymodem and use the previous operations to perform a full flash this time
+    of all partitions.
+
+    Note that if you erased your MRD partition, you lost your serial and MAC address. There's no way to recover the original one
+    except by reading the physical label on your… device!
+
+    If you super-hard-bricked your AP, i.e. no output on serial console, congratulations, you reached one of the rare state
+    of this device. You need an external NAND flasher to repair it and write the first stage from Mediatek to continue the previous
+    recovery operations.
+
+    Development TODO list:
+
+    - Better support for upgrade automation w.r.t. to A/B, e.g. automagic scripts.
+    - Mount the logs partition, mount / as overlayfs of firmware ? rootfs and rootfs_data for extended data.
+    - Jitter-based entropy injection? Device can be slow to initialize its CRNG and hostapd will reject few clients at the start because of that.
+    - Defaults for hostapd based on MT7915 capabilities? See the example for one possible list.
+    - Remove primary/secondary hack and put it in preinit.
+    - Offer ways to reflash the *bootloader* itself to support direct boot via UBI and kernel upgrades via filesystem rewrite.
+
+    Vendor web page: https://www.zyxel.com/fr/fr/products/wireless/ax1800-wifi-6-dual-radio-nebulaflex-access-point-nwa50ax
+
+    OpenWrt web page: https://openwrt.org/inbox/toh/zyxel/nwa50ax
+    OpenWrt tech data: https://openwrt.org/toh/hwdata/zyxel/zyxel_nwa50ax
+
+  '';
+
+  module = { pkgs, config, lib, lim, ...}:
+    let
+      inherit (pkgs.pseudofile) dir symlink;
+      inherit (pkgs) openwrt;
+
+      mac80211 = pkgs.mac80211.override {
+        drivers = [ "mt7915e" ];
+        klibBuild = config.system.outputs.kernel.modulesupport;
+      };
+      # v204520220929
+      wlan_firmware = pkgs.fetchurl {
+        url = "https://github.com/openwrt/mt76/raw/1b88dd07f153b202e57fe29734806744ed006b0e/firmware/mt7915_wa.bin";
+        hash = "sha256-wooyefzb0i8640+lwq3vNhcBXRFCtGuo+jiL7afZaKA=";
+      };
+      wlan_firmware' = pkgs.fetchurl {
+        url = "https://github.com/openwrt/mt76/raw/1b88dd07f153b202e57fe29734806744ed006b0e/firmware/mt7915_wm.bin";
+        hash = "sha256-k62nQewRuKjBLd5R3RxU4F74YKnQx5zr6gqMMImqVQw=";
+      };
+      wlan_firmware'' = pkgs.fetchurl {
+        url = "https://github.com/openwrt/mt76/raw/1b88dd07f153b202e57fe29734806744ed006b0e/firmware/mt7915_rom_patch.bin";
+        hash = "sha256-ifriAjWzFACrxVWCANZpUaEZgB/0pdbhnTVQytx6ddg=";
+      };
+    in {
+      imports = [ 
+        # We include it to ensure the bridge functionality
+        # is available on the target kernel.
+        ../../modules/bridge
+        ../../modules/arch/mipsel.nix
+        ../../modules/outputs/tftpboot.nix
+        ../../modules/outputs/zyxel-nwa-fit.nix
+        ../../modules/zyxel-dual-image
+      ];
+
+      filesystem = dir {
+        lib = dir {
+          firmware = dir {
+            mediatek = dir {
+              "mt7915_wa.bin" = symlink wlan_firmware;
+              "mt7915_wm.bin" = symlink wlan_firmware';
+              "mt7915_rom_patch.bin" = symlink wlan_firmware'';
+            };
+          };
+        };
+      };
+
+      rootfsType = "ubifs";
+      hardware = {
+        # Taken from OpenWRT
+        # root@OpenWrt:/# ubinfo /dev/ubi0
+        # ubi0
+        # Volumes count:                           2
+        # Logical eraseblock size:                 126976 bytes, 124.0 KiB
+        # Total amount of logical eraseblocks:     256 (32505856 bytes, 31.0 MiB)
+        # Amount of available logical eraseblocks: 0 (0 bytes)
+        # Maximum count of volumes                 128
+        # Count of bad physical eraseblocks:       0
+        # Count of reserved physical eraseblocks:  19
+        # Current maximum erase counter value:     2
+        # Minimum input/output unit size:          2048 bytes
+        # Character device major/minor:            250:0
+        # Present volumes:                         0, 1
+        ubi = {
+          minIOSize = "2048";
+          logicalEraseBlockSize = "126976";
+          physicalEraseBlockSize = "128KiB";
+          maxLEBcount = "256";
+        };
+
+        # This is a FIT containing a kernel padded and
+        # a UBI volume rootfs.
+        defaultOutput = "zyxel-nwa-fit";
+
+        loadAddress = lim.parseInt "0x80001000";
+        entryPoint = lim.parseInt "0x80001000";
+        # Aligned on 2kb.
+        alignment = 2048;
+
+        rootDevice = "ubi:rootfs";
+
+        dts = {
+          # Actually, this is not what we want.
+          # This DTS is insufficient.
+          src = ./mt7621_zyxel_nwa50ax.dtsi;
+          includes = [
+            # Here's one weird trick to make `ubi` detection
+            # out of the box.
+            # We will write ubi on /dev/firmware_a:rootfs location
+            # and same for /dev/firmware_b:rootfs.
+            # How do we distinguish both?
+            # We can just use the DTS to point ubi at A or B.
+            # This, unfortunately, means that we have "two images".
+            # But they are really just 1 image with 2 different DTS.
+            # TODO: improve this hack in preinit?
+            (if config.boot.imageType == "primary" then "${./a_image}" else "${./b_image}")
+            "${openwrt.src}/target/linux/ramips/dts"
+          ];
+        };
+        networkInterfaces =
+          let
+            inherit (config.system.service.network) link;
+          in {
+            eth = link.build { ifname = "eth0"; };
+            lan = link.build { ifname = "lan"; };
+            wlan0 = link.build {
+              ifname = "wlan0";
+              dependencies = [ mac80211 ];
+            };
+            wlan1 = link.build {
+              ifname = "wlan1";
+              dependencies = [ mac80211 ];
+            };
+          };
+      };
+
+      boot = {
+        # Critical because NWA50AX will extend your cmdline with the image number booted.
+        # and some bootloader version.
+        # You don't want to find yourself being overridden.
+        commandLineDtbNode = "bootargs-override";
+
+        imageFormat = "fit";
+        tftp = {
+          # 5MB is nice.
+          freeSpaceBytes = 5 * 1024 * 1024;
+          loadAddress = lim.parseInt "0x2000000";
+        };
+      };
+
+      # Dual image management service in userspace.
+      services.zyxel-dual-image = config.boot.zyxel-dual-image.build {
+        ensureActiveImage = "primary";
+        # TODO: use mtd names rather…
+        # primary and secondary are always /dev/mtd3 by virtue of the 
+        # dtb being not too wrong…
+        # TODO: remove this hack.
+        primaryMtdPartition = "/dev/mtd3";
+        secondaryMtdPartition = "/dev/mtd3";
+        bootConfigurationMtdPartition = "/dev/mtd12";
+      };
+
+      #  DEVICE_VENDOR := ZyXEL
+      #  KERNEL_SIZE := 8192k
+      #  DEVICE_PACKAGES := kmod-mt7915-firmware zyxel-bootconfig
+      #  KERNEL := kernel-bin | lzma | fit lzma $$(KDIR)/image-$$(firstword $$(DEVICE_DTS)).dtb
+      #  IMAGES += factory.bin ramboot-factory.bin
+      #  IMAGE/factory.bin := append-kernel | pad-to $$(KERNEL_SIZE) | append-ubi | zyxel-nwa-fit
+      #  IMAGE/ramboot-factory.bin := append-kernel | pad-to $$(KERNEL_SIZE) | append-ubi
+
+      kernel = {
+        src = pkgs.fetchurl {
+          name = "linux.tar.gz";
+          url = "https://cdn.kernel.org/pub/linux/kernel/v5.x/linux-5.15.137.tar.gz";
+          hash = "sha256-PkdzUKZ0IpBiWe/RS70J76JKnBFzRblWcKlaIFNxnHQ=";
+        };
+        extraPatchPhase = ''
+          ${openwrt.applyPatches.ramips}
+
+        '';
+        config = {
+
+          RALINK = "y";
+          PCI = "y";
+          PHY_MT7621_PCI = "y";
+          PCIE_MT7621 = "y";
+          SOC_MT7621 = "y";
+          CLK_MT7621 = "y";
+          CLOCKSOURCE_WATCHDOG = "y";
+
+          SERIAL_8250_CONSOLE = "y";
+          SERIAL_8250 = "y";
+          SERIAL_CORE_CONSOLE = "y";
+          SERIAL_OF_PLATFORM = "y";
+          SERIAL_8250_NR_UARTS = "3";
+          SERIAL_8250_RUNTIME_UARTS = "3";
+          SERIAL_MCTRL_GPIO = "y";
+
+          CONSOLE_LOGLEVEL_DEFAULT = "8";
+          CONSOLE_LOGLEVEL_QUIET = "4";
+
+          # MTD_UBI_BEB_LIMIT = "20";
+          # MTD_UBI_WL_THRESHOLD = "4096";
+
+          MTD = "y";
+          MTD_BLOCK = "y";          # fix undefined ref to register_mtd_blktrans_dev
+          MTD_RAW_NAND = "y";
+          MTD_NAND_MT7621 = "y";
+          MTD_NAND_MTK_BMT = "y";      # Bad-block Management Table
+          MTD_NAND_ECC_SW_HAMMING= "y";
+          MTD_SPI_NAND= "y";
+          MTD_OF_PARTS = "y";
+          MTD_NAND_CORE= "y";
+          MTD_SPLIT_FIRMWARE= "y";
+          MTD_SPLIT_FIT_FW= "y";
+
+          PINCTRL = "y";
+          PINCTRL_MT7621 = "y";
+
+          I2C = "y";
+          I2C_MT7621 = "y";
+
+          SPI = "y";
+          MTD_SPI_NOR = "y";
+          SPI_MT7621 = "y";
+          SPI_MASTER = "y";
+          SPI_MEM = "y";
+
+          REGULATOR = "y";
+          REGULATOR_FIXED_VOLTAGE = "y";
+          RESET_CONTROLLER = "y";
+          POWER_RESET = "y";
+          POWER_RESET_GPIO = "y";
+          POWER_SUPPLY = "y";
+          LED_TRIGGER_PHY = "y";
+
+          PCI_DISABLE_COMMON_QUIRKS = "y";
+          PCI_DOMAINS = "y";
+          PCI_DOMAINS_GENERIC = "y";
+          PCI_DRIVERS_GENERIC = "y";
+          PCS_MTK_LYNXI = "y";
+
+          SOC_BUS = "y";
+
+          NET = "y";
+          ETHERNET = "y";
+          WLAN = "y";
+
+          PHYLIB = "y";
+          AT803X_PHY = "y";
+          FIXED_PHY = "y";
+          GENERIC_PHY = "y";
+          NET_DSA = "y";
+          NET_DSA_MT7530 = "y";
+          NET_DSA_MT7530_MDIO = "y";
+          NET_DSA_TAG_MTK = "y";
+          NET_MEDIATEK_SOC = "y";
+          NET_SWITCHDEV = "y";
+          NET_VENDOR_MEDIATEK = "y";
+
+          SWPHY = "y";
+
+          GPIOLIB = "y";
+          GPIO_MT7621 = "y";
+          OF_GPIO = "y";
+
+          EARLY_PRINTK = "y";
+
+          NEW_LEDS = "y";
+          LEDS_TRIGGERS = "y";
+          LEDS_CLASS = "y";         # required by rt2x00lib
+          LEDS_CLASS_MULTICOLOR = "y";
+          LEDS_BRIGHTNESS_HW_CHANGED = "y";
+
+          PRINTK_TIME = "y";
+        } // lib.optionalAttrs (config.system.service ? vlan) {
+          SWCONFIG = "y";
+        } // lib.optionalAttrs (config.system.service ? watchdog) {
+          RALINK_WDT = "y";  # watchdog
+          MT7621_WDT = "y";  # or it might be this one
+        };
+      };
+    };
+}