add Raspberry Pi JTAG server configuration.nix

rpi-etc-nixos/configuration.nix

@@ -0,0 +1,44 @@
+{ config, pkgs, lib, ... }:
+let
+  m-labs = import (fetchTarball https://nixbld.m-labs.hk/channel/custom/artiq/main/channel/nixexprs.tar.xz) {};
+in
+{
+  boot.loader.grub.enable = false;
+  boot.loader.generic-extlinux-compatible.enable = true;
+ 
+  boot.kernelPackages = pkgs.linuxPackages_latest;
+  
+  boot.kernelParams = ["cma=32M console=ttyS1,115200n8"];
+    
+  fileSystems = {
+    "/boot" = {
+      device = "/dev/disk/by-label/NIXOS_BOOT";
+      fsType = "vfat";
+    };
+    "/" = {
+      device = "/dev/disk/by-label/NIXOS_SD";
+      fsType = "ext4";
+    };
+  };
+
+  services.openssh.enable = true;
+
+  networking.hostName = "rpi-1";
+  time.timeZone = "Asia/Hong_Kong";
+
+  users.extraGroups.plugdev = { };
+  users.extraUsers.sb = {
+    isNormalUser = true;
+    extraGroups = ["wheel" "plugdev" "dialout"];
+    uid = 1000;
+  };
+  security.sudo.wheelNeedsPassword = false;
+  services.udev.packages = [ m-labs.openocd ];
+
+  environment.systemPackages = with pkgs; [
+    wget vim git usbutils mosh tmux xc3sprog m-labs.openocd
+  ];
+
+  nix.binaryCachePublicKeys = ["nixbld.m-labs.hk-1:5aSRVA5b320xbNvu30tqxVPXpld73bhtOeH6uAjRyHc="];
+  nix.binaryCaches = ["https://cache.nixos.org" "https://nixbld.m-labs.hk"];
+}