feat(uconsole): add cm5 cross-compiled nixosConfiguration

- New host: uconsole-cm5 (aarch64-linux, cross-built from x86_64)
- SSH authorizedKeys: gortium.main + ai-worker.main
- NetworkManager enabled (WiFi password via agenix later)
- Display: vc4/panel_cwu50/rp1_dsi with empty initrd
- Config.txt [pi5] section (not [cm5])
- Backlight fix service
- nixos-raspberrypi → gortium/cm5-cross-v1 fork (PR #197)
- nixpkgs-uconsole pinned to nixos-25.11 (kernel patch compat)

V3 branch saved as archive/uconsole-cm5-v3 (Reticulum/SDR/HAM config).

flake.nix

@@ -12,10 +12,23 @@
       url = "git+https://git.lix.systems/lix-project/lix?ref=main";
       inputs.nixpkgs.follows = "nixpkgs";
     };
+
+    # uConsole CM5 — pinned nixpkgs for kernel patch compatibility
+    nixpkgs-uconsole.url = "github:NixOS/nixpkgs/nixos-25.11";
+    nixos-uconsole = {
+      url = "github:nixos-uconsole/nixos-uconsole/v1.1.0";
+      inputs.nixpkgs.follows = "nixpkgs-uconsole";
+    };
+    nixos-raspberrypi = {
+      url = "github:gortium/nixos-raspberrypi/cm5-cross-v1";
+      inputs.nixpkgs.follows = "nixpkgs-uconsole";
+    };
     self.submodules = true;
   };
 
-  outputs = { self, nixpkgs, agenix, lix, ... }@inputs:
+  outputs = { self, nixpkgs, agenix, lix
+            , nixpkgs-uconsole, nixos-uconsole, nixos-raspberrypi
+            , ... }@inputs:
     let
       system = "x86_64-linux";
       keys = import ./lib/keys.nix;
@@ -80,6 +93,48 @@
               ./hosts/cyt-pi/hardware-configuration.nix
             ];
           };
+
+          # ============================================================
+          # uConsole CM5 — cross-compilé (build sur x86_64, run sur ARM)
+          # Approche incrémentale pour fixer l'écran
+          # ============================================================
+          uconsole-cm5 = nixpkgs-uconsole.lib.nixosSystem {
+            system = "aarch64-linux";
+            specialArgs = {
+              inherit self keys paths inputs;
+              nixos-raspberrypi = nixos-raspberrypi;
+              isCM4 = false;
+            };
+            modules = [
+              {
+                # Cross-compile : build sur x86_64, run sur aarch64
+                nixpkgs.buildPlatform = "x86_64-linux";
+                nixpkgs.hostPlatform = "aarch64-linux";
+                nixpkgs.config.allowUnfree = true;
+                boot.loader.raspberry-pi.bootloader = "kernel";
+              }
+              # nixos-raspberrypi — crée pkgs.rpi avec kernel/firmware cross-compilés
+              nixos-raspberrypi.nixosModules.nixpkgs-rpi
+              {
+                nixpkgs.overlays = [
+                  nixos-raspberrypi.overlays.bootloader
+                  nixos-raspberrypi.overlays.vendor-kernel
+                  nixos-raspberrypi.overlays.vendor-firmware
+                  nixos-raspberrypi.overlays.kernel-and-firmware
+                  nixos-raspberrypi.overlays.vendor-pkgs
+                  nixos-raspberrypi.overlays.pkgs
+                ];
+              }
+              # nixos-uconsole CM5 modules
+              nixos-uconsole.nixosModules.kernel
+              nixos-uconsole.nixosModules.configtxt
+              (nixos-uconsole.nixosModules.cm { lib = nixpkgs-uconsole.lib; isCM4 = false; })
+              nixos-uconsole.nixosModules.base
+              # Notre config
+              ./hosts/uconsole-cm5/configuration.nix
+              ./hosts/uconsole-cm5/hardware-configuration.nix
+            ];
+          };
         };
         devShells.${system}.default = devShell;
       };

hosts/uconsole-cm5/configuration.nix

@@ -0,0 +1,112 @@
+{ config, lib, pkgs, keys, ... }:
+
+{
+  # Basic Host Info
+  networking.hostName = "uConsole";
+  time.timeZone = "America/Montreal";
+  i18n.defaultLocale = "en_CA.UTF-8";
+  system.stateVersion = "25.11";
+
+  # ============================================================
+  # SSH Access — ta clé + clé de déploiement
+  # ============================================================
+  services.openssh = {
+    enable = true;
+    settings.PermitRootLogin = "prohibit-password";
+    settings.PasswordAuthentication = false;
+  };
+
+  users.users.root = {
+    openssh.authorizedKeys.keys = [
+      keys.users.gortium.main
+      keys.users.ai-worker.main
+    ];
+  };
+
+  # ============================================================
+  # Networking — WiFi via NetworkManager
+  # ============================================================
+  networking.networkmanager.enable = true;
+
+  # WiFi connection — Thierry ajoutera le password dans un secret agenix
+  # networking.networkmanager.connections = { ... };
+
+  # ============================================================
+  # Kernel parameters from nixos-uconsole CM5 module
+  # ============================================================
+  boot.kernelParams = [
+    "8250.nr_uarts=1"
+    "console=tty1"
+  ];
+
+  # ============================================================
+  # Console font for 5" 720x1280 display
+  # ============================================================
+  console = {
+    earlySetup = true;
+    font = "ter-v24n";
+    packages = with pkgs; [ terminus_font ];
+  };
+
+  # ============================================================
+  # Display — vc4/panel_cwu50 loaded AFTER RP1 PCIe init
+  # Rien dans initrd — tout RP1 est derrière PCIe
+  # ============================================================
+  hardware.graphics.enable = true;
+
+  boot.kernelModules = [
+    "panel_cwu50"     # uConsole DSI panel driver
+    "vc4"             # VideoCore 4 KMS GPU driver
+    "rp1_dsi"         # RP1 DSI bridge driver
+  ];
+
+  boot.initrd.kernelModules = lib.mkForce [ ];
+
+  # ============================================================
+  # CM5 Config.txt — [pi5] section (pas [cm5])
+  # ============================================================
+  hardware.raspberry-pi.extra-config = ''
+    [all]
+    gpio=10=ip,np
+    gpio=11=op,dh
+
+    [pi5]
+    dtparam=pciex1=off
+    dtoverlay=clockworkpi-uconsole-cm5
+    dtoverlay=dwc2,dr_mode=host
+    dtoverlay=vc4-kms-v3d-pi5,cma-384
+    dtparam=nohdmi1=off
+  '';
+
+  # ============================================================
+  # CM5 Display Backlight Fix
+  # ============================================================
+  systemd.services.cm5-backlight-fix = {
+    description = "CM5 Display Backlight Fix";
+    after = [ "multi-user.target" ];
+    wantedBy = [ "multi-user.target" ];
+    serviceConfig = {
+      Type = "oneshot";
+      ExecStart = let
+        fixScript = pkgs.writeShellScript "backlight-fix" ''
+          for bl in /sys/class/backlight/*/brightness; do
+            if [ -f "$bl" ]; then
+              max=$(cat "$(dirname "$bl")/max_brightness" 2>/dev/null || echo 100)
+              echo "$max" > "$bl" 2>/dev/null || true
+            fi
+          done
+        '';
+      in "${fixScript}";
+    };
+  };
+
+  # ============================================================
+  # Minimal packages
+  # ============================================================
+  environment.systemPackages = with pkgs; [
+    git
+    vim
+    htop
+    libgpiod      # GPIO control
+  ];
+}

hosts/uconsole-cm5/hardware-configuration.nix

@@ -0,0 +1,30 @@
+{ config, lib, pkgs, modulesPath, ... }:
+
+{
+  imports = [
+    (modulesPath + "/installer/scan/not-detected.nix")
+  ];
+
+  boot.initrd.availableKernelModules = [ "xhci_pci" "usbhid" "usb_storage" "sdhci_pci" "nvme" ];
+  boot.initrd.kernelModules = [ ];
+  boot.extraModulePackages = [ ];
+
+  # SD card partitions (nixos-uconsole layout)
+  fileSystems."/" = {
+    device = "/dev/disk/by-label/NIXOS_SD";
+    fsType = "ext4";
+    options = [ "noatime" ];
+  };
+
+  fileSystems."/boot/firmware" = {
+    device = "/dev/disk/by-label/FIRMWARE";
+    fsType = "vfat";
+    options = [ "fmask=0022" "dmask=0022" ];
+  };
+
+  swapDevices = [ ];
+
+  nixpkgs.hostPlatform = lib.mkDefault "aarch64-linux";
+  hardware.enableRedistributableFirmware = true;
+  powerManagement.cpuFreqGovernor = lib.mkDefault "ondemand";
+}