Enable optimized builds for steam deck.

nix/configuration/configuration.nix

@@ -118,6 +118,14 @@
       home.stateVersion = "24.11";
     };
 
+  home-manager.users.root =
+    { pkgs, ... }:
+    {
+      # The state version is required and should stay at the version you
+      # originally installed.
+      home.stateVersion = "24.11";
+    };
+
   # Automatic garbage collection
   nix.gc = lib.mkIf (!config.me.buildingIso) {
     # Runs nix-collect-garbage --delete-older-than 5d
@@ -163,6 +171,7 @@
     doas-sudo-shim # To support --use-remote-sudo for remote builds
     dmidecode # Read SMBIOS information.
     ipcalc
+    gptfdisk # for cgdisk
   ];
 
   services.openssh = {

nix/configuration/flake.lock

@@ -135,11 +135,11 @@
         ]
       },
       "locked": {
-        "lastModified": 1741955947,
+        "lastModified": 1742588233,
-        "narHash": "sha256-2lbURKclgKqBNm7hVRtWh0A7NrdsibD0EaWhahUVhhY=",
+        "narHash": "sha256-Fi5g8H5FXMSRqy+mU6gPG0v+C9pzjYbkkiePtz8+PpA=",
         "owner": "nix-community",
         "repo": "home-manager",
-        "rev": "4e12151c9e014e2449e0beca2c0e9534b96a26b4",
+        "rev": "296ddc64627f4a6a4eb447852d7346b9dd16197d",
         "type": "github"
       },
       "original": {
@@ -191,11 +191,11 @@
     },
     "nixpkgs": {
       "locked": {
-        "lastModified": 1741851582,
+        "lastModified": 1742422364,
-        "narHash": "sha256-cPfs8qMccim2RBgtKGF+x9IBCduRvd/N5F4nYpU0TVE=",
+        "narHash": "sha256-mNqIplmEohk5jRkqYqG19GA8MbQ/D4gQSK0Mu4LvfRQ=",
         "owner": "NixOS",
         "repo": "nixpkgs",
-        "rev": "6607cf789e541e7873d40d3a8f7815ea92204f32",
+        "rev": "a84ebe20c6bc2ecbcfb000a50776219f48d134cc",
         "type": "github"
       },
       "original": {
@@ -237,6 +237,22 @@
         "type": "github"
       }
     },
+    "nixpkgs-unoptimized": {
+      "locked": {
+        "lastModified": 1742422364,
+        "narHash": "sha256-mNqIplmEohk5jRkqYqG19GA8MbQ/D4gQSK0Mu4LvfRQ=",
+        "owner": "NixOS",
+        "repo": "nixpkgs",
+        "rev": "a84ebe20c6bc2ecbcfb000a50776219f48d134cc",
+        "type": "github"
+      },
+      "original": {
+        "owner": "NixOS",
+        "ref": "nixos-unstable",
+        "repo": "nixpkgs",
+        "type": "github"
+      }
+    },
     "pre-commit-hooks-nix": {
       "inputs": {
         "flake-compat": [
@@ -272,6 +288,7 @@
         "lanzaboote": "lanzaboote",
         "nixpkgs": "nixpkgs",
         "nixpkgs-b93b4e9b5": "nixpkgs-b93b4e9b5",
+        "nixpkgs-unoptimized": "nixpkgs-unoptimized",
         "zsh-histdb": "zsh-histdb"
       }
     },

nix/configuration/flake.nix

@@ -32,6 +32,7 @@
     impermanence.url = "github:nix-community/impermanence";
     nixpkgs.url = "github:NixOS/nixpkgs/nixos-unstable";
     nixpkgs-b93b4e9b5.url = "github:NixOS/nixpkgs/b93b4e9b527904aadf52dba6ca35efde2067cbd4";
+    nixpkgs-unoptimized.url = "github:NixOS/nixpkgs/nixos-unstable";
     home-manager.url = "github:nix-community/home-manager";
     home-manager.inputs.nixpkgs.follows = "nixpkgs";
     lanzaboote = {
@@ -58,6 +59,7 @@
     {
       self,
       nixpkgs,
+      nixpkgs-unoptimized,
       nixpkgs-b93b4e9b5,
       impermanence,
       home-manager,
@@ -73,6 +75,11 @@
           pkgs-b93b4e9b5 = import nixpkgs-b93b4e9b5 {
             inherit system;
           };
+          pkgs-unoptimized = import nixpkgs-unoptimized {
+            inherit system;
+            hostPlatform.gcc.arch = "default";
+            hostPlatform.gcc.tune = "default";
+          };
         };
         modules = [
           impermanence.nixosModules.impermanence
@@ -142,6 +149,30 @@
             }
           );
         };
+        hydra = {
+          main = nixpkgs.lib.nixosSystem (
+            base_x86_64_linux
+            // {
+              modules = base_x86_64_linux.modules ++ [
+                ./hosts/hydra
+              ];
+            }
+          );
+          iso = nixpkgs.lib.nixosSystem (
+            base_x86_64_linux
+            // {
+              modules = base_x86_64_linux.modules ++ [
+                ./hosts/hydra
+                (nixpkgs + "/nixos/modules/installer/cd-dvd/iso-image.nix")
+                {
+                  isoImage.makeEfiBootable = true;
+                  isoImage.makeUsbBootable = true;
+                  me.buildingIso = true;
+                }
+              ];
+            }
+          );
+        };
       };
     in
     {
@@ -149,5 +180,7 @@
       iso.odo = systems.odo.iso.config.system.build.isoImage;
       nixosConfigurations.neelix = systems.neelix.main;
       iso.neelix = systems.neelix.iso.config.system.build.isoImage;
+      nixosConfigurations.hydra = systems.hydra.main;
+      iso.hydra = systems.hydra.iso.config.system.build.isoImage;
     };
 }

nix/configuration/hosts/hydra/default.nix

@@ -0,0 +1,32 @@
+{ config, pkgs, ... }:
+{
+  imports = [
+    ./hardware-configuration.nix
+    ./disk-config.nix
+    ./optimized_build.nix
+  ];
+
+  # Generate with `head -c4 /dev/urandom | od -A none -t x4`
+  networking.hostId = "fbd233d8";
+
+  networking.hostName = "hydra"; # Define your hostname.
+
+  time.timeZone = "America/New_York";
+  i18n.defaultLocale = "en_US.UTF-8";
+
+  me.secureBoot.enable = false;
+
+  # Mount tmpfs at /tmp
+  boot.tmp.useTmpfs = true;
+
+  me.emacs_flavor = "plainmacs";
+  me.graphical = false;
+  me.zsh.enable = true;
+  me.wireguard.activated = [ ];
+  me.wireguard.deactivated = [ ];
+
+  # Trust this key so nix running as root can ssh into hydra.
+  users.users.talexander.openssh.authorizedKeys.keys = [
+    "ssh-ed25519 AAAAC3NzaC1lZDI1NTE5AAAAIB/IlYTQ0M5pFN5tdoswh37CDl/gbULI3h+SsKXCansh talexander@odo"
+  ];
+}

nix/configuration/hosts/hydra/disk-config.nix

@@ -0,0 +1,140 @@
+# Manual Step:
+#   Check if drive supports 4kn: nvme id-ns -H /dev/nvme0n1
+#   Format the drive to 4kn: nvme format --lbaf=1 /dev/nvme0n1
+{
+  config,
+  lib,
+  pkgs,
+  ...
+}:
+
+lib.mkIf (!config.me.buildingIso) {
+  disko.devices = {
+    disk = {
+      main = {
+        type = "disk";
+        device = "/dev/nvme0n1";
+        content = {
+          type = "gpt";
+          partitions = {
+            ESP = {
+              size = "1G";
+              type = "EF00";
+              content = {
+                type = "filesystem";
+                format = "vfat";
+                mountpoint = "/boot";
+                mountOptions = [
+                  "umask=0077"
+                  "noatime"
+                  "discard"
+                ];
+              };
+            };
+            zfs = {
+              size = "100%";
+              content = {
+                type = "zfs";
+                pool = "zroot";
+              };
+            };
+          };
+        };
+      };
+    };
+    zpool = {
+      zroot = {
+        type = "zpool";
+        # mode = "mirror";
+        # Workaround: cannot import 'zroot': I/O error in disko tests
+        options.cachefile = "none";
+        options = {
+          ashift = "12";
+          compatibility = "openzfs-2.2-freebsd";
+          autotrim = "on";
+        };
+        rootFsOptions = {
+          acltype = "posixacl";
+          atime = "off";
+          relatime = "off";
+          xattr = "sa";
+          mountpoint = "none";
+          compression = "lz4";
+          canmount = "off";
+          utf8only = "on";
+          dnodesize = "auto";
+          normalization = "formD";
+        };
+
+        datasets = {
+          "linux/nix" = {
+            type = "zfs_fs";
+            options.mountpoint = "none";
+          };
+          "linux/nix/root" = {
+            type = "zfs_fs";
+            options.mountpoint = "legacy";
+            mountpoint = "/";
+            postCreateHook = "zfs list -t snapshot -H -o name | grep -E '^zroot/linux/nix/root@blank$' || zfs snapshot zroot/linux/nix/root@blank";
+          };
+          "linux/nix/nix" = {
+            type = "zfs_fs";
+            options.mountpoint = "legacy";
+            mountpoint = "/nix";
+            postCreateHook = "zfs list -t snapshot -H -o name | grep -E '^zroot/linux/nix/nix@blank$' || zfs snapshot zroot/linux/nix/nix@blank";
+            options = {
+              recordsize = "1MiB";
+              compression = "lz4";
+            };
+          };
+          "linux/nix/home" = {
+            type = "zfs_fs";
+            options.mountpoint = "legacy";
+            mountpoint = "/home";
+            postCreateHook = "zfs list -t snapshot -H -o name | grep -E '^zroot/linux/nix/home@blank$' || zfs snapshot zroot/linux/nix/home@blank";
+          };
+          "linux/nix/persist" = {
+            type = "zfs_fs";
+            options.mountpoint = "legacy";
+            mountpoint = "/persist";
+            postCreateHook = "zfs list -t snapshot -H -o name | grep -E '^zroot/linux/nix/persist@blank$' || zfs snapshot zroot/linux/nix/persist@blank";
+          };
+          "linux/nix/state" = {
+            type = "zfs_fs";
+            options.mountpoint = "legacy";
+            mountpoint = "/state";
+            postCreateHook = "zfs list -t snapshot -H -o name | grep -E '^zroot/linux/nix/state@blank$' || zfs snapshot zroot/linux/nix/state@blank";
+          };
+        };
+      };
+    };
+  };
+
+  # Make sure all persistent volumes are marked as neededForBoot
+  #
+  # Also mounts /home so it is mounted before the user home directories are created.
+  fileSystems."/persist".neededForBoot = true;
+  fileSystems."/state".neededForBoot = true;
+  fileSystems."/home".neededForBoot = true;
+
+  fileSystems."/".options = [
+    "noatime"
+    "norelatime"
+  ];
+  fileSystems."/nix".options = [
+    "noatime"
+    "norelatime"
+  ];
+  fileSystems."/persist".options = [
+    "noatime"
+    "norelatime"
+  ];
+  fileSystems."/state".options = [
+    "noatime"
+    "norelatime"
+  ];
+  fileSystems."/home".options = [
+    "noatime"
+    "norelatime"
+  ];
+}

nix/configuration/hosts/hydra/hardware-configuration.nix

@@ -0,0 +1,39 @@
+# Do not modify this file!  It was generated by ‘nixos-generate-config’
+# and may be overwritten by future invocations.  Please make changes
+# to /etc/nixos/configuration.nix instead.
+{
+  config,
+  lib,
+  pkgs,
+  modulesPath,
+  ...
+}:
+
+{
+  imports = [
+    (modulesPath + "/installer/scan/not-detected.nix")
+  ];
+
+  boot.initrd.availableKernelModules = [
+    "xhci_pci"
+    "nvme"
+    "usbhid"
+    "usb_storage"
+    "sd_mod"
+    "sdhci_pci"
+  ];
+  boot.initrd.kernelModules = [ ];
+  boot.kernelModules = [ ];
+  boot.extraModulePackages = [ ];
+
+  # Enables DHCP on each ethernet and wireless interface. In case of scripted networking
+  # (the default) this is the recommended approach. When using systemd-networkd it's
+  # still possible to use this option, but it's recommended to use it in conjunction
+  # with explicit per-interface declarations with `networking.interfaces.<interface>.useDHCP`.
+  networking.dhcpcd.enable = lib.mkForce true;
+  networking.useDHCP = lib.mkForce true;
+  networking.interfaces.enp0s2.useDHCP = lib.mkForce true;
+  # systemd.network.enable = true;
+
+  nixpkgs.hostPlatform = lib.mkDefault "x86_64-linux";
+}

nix/configuration/hosts/hydra/optimized_build.nix

@@ -0,0 +1,88 @@
+{
+  config,
+  lib,
+  pkgs,
+  ...
+}:
+{
+  imports = [ ];
+
+  config = lib.mkMerge [
+    {
+      nix.settings.system-features = lib.mkForce [
+        "gccarch-znver4"
+        "gccarch-x86-64-v3"
+        "gccarch-x86-64-v4"
+        "benchmark"
+        "big-parallel"
+        # "kvm"
+        # "nixos-test"
+      ];
+    }
+    (lib.mkIf (!config.me.buildingIso) {
+      nix.settings.system-features = lib.mkForce [
+        "gccarch-znver4"
+        "gccarch-x86-64-v3"
+        "gccarch-x86-64-v4"
+        "benchmark"
+        "big-parallel"
+        # "kvm"
+        # "nixos-test"
+      ];
+
+      # nixpkgs.hostPlatform = {
+      #   gcc.arch = "alderlake";
+      #   gcc.tune = "alderlake";
+      #   system = "x86_64-linux";
+      # };
+
+      nixpkgs.overlays = [
+        (
+          final: prev:
+          let
+            optimizeWithFlags =
+              pkg: flags:
+              pkg.overrideAttrs (old: {
+                NIX_CFLAGS_COMPILE = [ (old.NIX_CFLAGS_COMPILE or "") ] ++ flags;
+              });
+            addConfig =
+              additionalConfig: pkg:
+              pkg.override (oldconfig: {
+                structuredExtraConfig = pkg.structuredExtraConfig // additionalConfig;
+              });
+          in
+          {
+            linux_znver4 =
+              addConfig
+                {
+                  # Full preemption
+                  PREEMPT = lib.mkOverride 60 lib.kernel.yes;
+                  PREEMPT_VOLUNTARY = lib.mkOverride 60 lib.kernel.no;
+
+                  # Google's BBRv3 TCP congestion Control
+                  TCP_CONG_BBR = lib.kernel.yes;
+                  DEFAULT_BBR = lib.kernel.yes;
+
+                  # Preemptive Full Tickless Kernel at 300Hz
+                  HZ = lib.kernel.freeform "300";
+                  HZ_300 = lib.kernel.yes;
+                  HZ_1000 = lib.kernel.no;
+                }
+                (
+                  optimizeWithFlags prev.linux_6_13 [
+                    "-march=znver4"
+                    "-mtune=znver4"
+                  ]
+                );
+          }
+        )
+      ];
+
+      boot.kernelPackages = pkgs.linuxPackagesFor pkgs.linux_znver4;
+    })
+    (lib.mkIf (config.me.buildingIso) {
+      boot.kernelPackages = pkgs.linuxPackagesFor pkgs.linux_6_13;
+      boot.supportedFilesystems = [ "zfs" ];
+    })
+  ];
+}

nix/configuration/hosts/odo/default.nix

@@ -9,6 +9,7 @@
     ./hardware-configuration.nix
     ./disk-config.nix
     ./optimized_build.nix
+    ./distributed_build.nix
     ./power_management.nix
     ./screen_brightness.nix
     ./wifi.nix

nix/configuration/hosts/odo/distributed_build.nix

@@ -0,0 +1,32 @@
+{
+  config,
+  lib,
+  pkgs,
+  ...
+}:
+{
+  imports = [ ];
+
+  config = lib.mkMerge [
+    {
+      nix.distributedBuilds = true;
+      nix.buildMachines = [
+        {
+          hostName = "hydra";
+          systems = [
+            "x86_64-linux"
+            # "aarch64-linux"
+          ];
+          maxJobs = 1;
+          speedFactor = 2;
+          supportedFeatures = [
+            # "nixos-test"
+            "benchmark"
+            "big-parallel"
+            # "kvm"
+          ];
+        }
+      ];
+    }
+  ];
+}

nix/configuration/hosts/odo/optimized_build.nix

@@ -2,6 +2,7 @@
   config,
   lib,
   pkgs,
+  pkgs-unoptimized,
   ...
 }:
 {
@@ -25,11 +26,11 @@
       # Keep ALL dependencies so we can rebuild offline. This DRASTICALLY increase disk usage, but disk space is cheap.
       # system.includeBuildDependencies = true;
 
-      # nixpkgs.hostPlatform = {
+      nixpkgs.hostPlatform = {
-      #   gcc.arch = "znver4";
+        gcc.arch = "znver4";
-      #   gcc.tune = "znver4";
+        gcc.tune = "znver4";
-      #   system = "x86_64-linux";
+        system = "x86_64-linux";
-      # };
+      };
 
       nixpkgs.overlays = [
         (
@@ -77,6 +78,26 @@
             # });
           }
         )
+        (final: prev: {
+          haskellPackages = prev.haskellPackages.extend (
+            final': prev': {
+              crypton = pkgs-unoptimized.haskellPackages.crypton;
+            }
+          );
+        })
+        # (final: prev: {
+        #   haskell = prev.haskell // {
+        #     packageOverrides = final.lib.composeExtensions prev.haskell.packageOverrides (
+        #       final': prev': {
+        #         crypton = pkgs-unoptimized.haskellPackages.crypton;
+        #       }
+        #     );
+        #   };
+        # })
+        (final: prev: {
+          redis = pkgs-unoptimized.redis;
+          gsl = pkgs-unoptimized.gsl;
+        })
       ];
 
       boot.kernelPackages = pkgs.linuxPackagesFor pkgs.linux_znver4;

nix/configuration/roles/ssh/default.nix

@@ -28,4 +28,12 @@
         source = ./files/ssh_config;
       };
     };
+
+  home-manager.users.root =
+    { pkgs, ... }:
+    {
+      home.file.".ssh/config" = {
+        source = ./files/ssh_config_root;
+      };
+    };
 }

nix/configuration/roles/ssh/files/ssh_config

@@ -30,5 +30,9 @@ Host brianai
   ProxyJump talexander@mrmanager
   HostName 10.215.1.215
 
+Host hydra
+  ProxyJump talexander@mrmanager
+  HostName 10.215.1.219
+
 Host *
   Compression yes

nix/configuration/roles/ssh/files/ssh_config_root

@@ -0,0 +1,9 @@
+Host hydra
+  HostName ns1.fizz.buzz
+  Port 65122
+  User talexander
+  IdentitiesOnly yes
+  IdentityFile /persist/manual/ssh/root/keys/id_ed25519
+
+Host *
+  Compression yes

nix/configuration/roles/wasm/default.nix

@@ -2,6 +2,7 @@
   config,
   lib,
   pkgs,
+  pkgs-unoptimized,
   ...
 }:
 
@@ -23,7 +24,7 @@
         environment.systemPackages = with pkgs; [
           wabt
           wasm-bindgen-cli
-          binaryen # for wasm-opt
+          pkgs-unoptimized.binaryen # for wasm-opt
         ];
       }
     ]

nix/steam_deck/configuration/home.nix

@@ -8,8 +8,10 @@
 {
   imports = [
     ./roles/2ship2harkinian
+    ./roles/global_options
     ./roles/graphics
     ./roles/pcsx2
+    ./roles/rpcs3
     ./roles/shipwright
     ./roles/sm64ex
     ./roles/steam_rom_manager

nix/steam_deck/configuration/hosts/deck/default.nix

@@ -10,7 +10,9 @@
 
   config = {
     me.graphical = true;
+    me.optimizations.enable = true;
     me.pcsx2.enable = true;
+    me.rpcs3.enable = true;
     me.ship2harkinian.enable = true;
     me.shipwright.enable = true;
     me.sm64ex.enable = true;

nix/steam_deck/configuration/roles/2ship2harkinian/default.nix

@@ -54,11 +54,28 @@ in
         };
 
         nixpkgs.overlays = [
-          (final: prev: {
+          (
+            final: prev:
+            let
+              optimizeWithFlags =
+                pkg: flags:
+                pkg.overrideAttrs (old: {
+                  NIX_CFLAGS_COMPILE = [ (old.NIX_CFLAGS_COMPILE or "") ] ++ flags;
+                });
+              original_package =
+                if config.me.optimizations.enable then
+                  (optimizeWithFlags prev._2ship2harkinian [
+                    "-march=znver2"
+                    "-mtune=znver2"
+                  ])
+                else
+                  prev._2ship2harkinian;
+            in
+            {
               _2ship2harkinian = pkgs.buildEnv {
                 name = prev._2ship2harkinian.name;
                 paths = [
-                (config.lib.nixGL.wrap prev._2ship2harkinian)
+                  (config.lib.nixGL.wrap original_package)
                 ];
                 extraOutputsToInstall = [
                   "man"
@@ -70,7 +87,8 @@ in
                   chmod 0555 $out/share/applications/2s2h.desktop
                 '';
               };
-          })
+            }
+          )
         ];
       })
     ]

nix/steam_deck/configuration/roles/global_options/default.nix

@@ -0,0 +1,19 @@
+{
+  config,
+  lib,
+  pkgs,
+  ...
+}:
+
+{
+  imports = [ ];
+
+  options.me = {
+    optimizations.enable = lib.mkOption {
+      type = lib.types.bool;
+      default = false;
+      example = true;
+      description = "Whether we want to enable CPU optimizations (will trigger a rebuild from source).";
+    };
+  };
+}

nix/steam_deck/configuration/roles/pcsx2/default.nix

@@ -70,11 +70,28 @@ in
         };
 
         nixpkgs.overlays = [
-          (final: prev: {
+          (
+            final: prev:
+            let
+              optimizeWithFlags =
+                pkg: flags:
+                pkg.overrideAttrs (old: {
+                  NIX_CFLAGS_COMPILE = [ (old.NIX_CFLAGS_COMPILE or "") ] ++ flags;
+                });
+              original_package =
+                if config.me.optimizations.enable then
+                  (optimizeWithFlags prev.pcsx2 [
+                    "-march=znver2"
+                    "-mtune=znver2"
+                  ])
+                else
+                  prev.pcsx2;
+            in
+            {
               pcsx2 = pkgs.buildEnv {
                 name = prev.pcsx2.name;
                 paths = [
-                (config.lib.nixGL.wrap prev.pcsx2)
+                  (config.lib.nixGL.wrap original_package)
                 ];
                 extraOutputsToInstall = [
                   "man"
@@ -86,7 +103,8 @@ in
                   chmod 0555 $out/share/applications/PCSX2.desktop
                 '';
               };
-          })
+            }
+          )
         ];
       })
     ]

nix/steam_deck/configuration/roles/rpcs3/default.nix

@@ -0,0 +1,112 @@
+# MANUAL: mkdir -p ~/.state/.cache/rpcs3 ~/.persist/.config/rpcs3/dev_hdd0 ~/.persist/.config/rpcs3/dev_hdd1 ~/.persist/.config/rpcs3/savestates ~/.persist/.config/rpcs3/dev_usb000 ~/.persist/.config/rpcs3/dev_flash
+{
+  config,
+  lib,
+  pkgs,
+  ...
+}:
+
+let
+  steam_rpcs3 = pkgs.writeScriptBin "steam_rpcs3" ''
+    export LD_LIBRARY_PATH="$LD_LIBRARY_PATH:${pkgs.libglvnd}/lib"
+    exec ${pkgs.rpcs3}/bin/rpcs3
+  '';
+in
+{
+  imports = [ ];
+
+  options.me = {
+    rpcs3.enable = lib.mkOption {
+      type = lib.types.bool;
+      default = false;
+      example = true;
+      description = "Whether we want to install rpcs3.";
+    };
+  };
+
+  config = lib.mkIf config.me.rpcs3.enable (
+    lib.mkMerge [
+      (lib.mkIf config.me.graphical {
+        home.packages = with pkgs; [
+          rpcs3
+          steam_rpcs3
+        ];
+
+        # .config/rpcs3/config.yml
+        # .config/rpcs3/GuiConfigs/CurrentSettings.ini
+
+        home.persistence."/home/deck/.persist" = {
+          directories = [
+            {
+              directory = ".config/rpcs3/dev_hdd0";
+              method = "symlink";
+            }
+            {
+              directory = ".config/rpcs3/dev_hdd1";
+              method = "symlink";
+            }
+            {
+              directory = ".config/rpcs3/savestates";
+              method = "symlink";
+            }
+            {
+              directory = ".config/rpcs3/dev_usb000";
+              method = "symlink";
+            }
+            {
+              # Seems to be where the firmware is installed.
+              directory = ".config/rpcs3/dev_flash";
+              method = "symlink";
+            }
+          ];
+        };
+        home.persistence."/home/deck/.state" = {
+          directories = [
+            {
+              directory = ".cache/rpcs3";
+              method = "symlink";
+            }
+          ];
+        };
+
+        nixpkgs.overlays = [
+          (
+            final: prev:
+            let
+              optimizeWithFlags =
+                pkg: flags:
+                pkg.overrideAttrs (old: {
+                  NIX_CFLAGS_COMPILE = [ (old.NIX_CFLAGS_COMPILE or "") ] ++ flags;
+                });
+              original_package =
+                if config.me.optimizations.enable then
+                  (optimizeWithFlags prev.rpcs3 [
+                    "-march=znver2"
+                    "-mtune=znver2"
+                  ])
+                else
+                  prev.rpcs3;
+            in
+            {
+              rpcs3 = pkgs.buildEnv {
+                name = prev.rpcs3.name;
+                paths = [
+                  (config.lib.nixGL.wrap original_package)
+                ];
+                extraOutputsToInstall = [
+                  "man"
+                  "doc"
+                  "info"
+                ];
+                # We have to use 555 instead of the normal 444 here because the .desktop file ends up inside $HOME on steam deck and desktop files must be either not in $HOME or must be executable, otherwise KDE Plasma refuses to execute them.
+                postBuild = ''
+                  chmod 0555 $out/share/applications/rpcs3.desktop
+                '';
+              };
+            }
+          )
+        ];
+      })
+    ]
+  );
+}

nix/steam_deck/configuration/roles/shipwright/default.nix

@@ -54,11 +54,30 @@ in
         };
 
         nixpkgs.overlays = [
-          (final: prev: {
+          (
+            final: prev:
+            let
+              optimizeWithFlags =
+                pkg: flags:
+                pkg.overrideAttrs (old: {
+                  NIX_CFLAGS_COMPILE = [ (old.NIX_CFLAGS_COMPILE or "") ] ++ flags;
+                });
+              original_package = prev.shipwright;
+              # Optimization is broken for shipwright, fails to build "The following attributes are overlapping"
+              # original_package =
+              #   if !config.me.optimizations.enable then
+              #     (optimizeWithFlags prev.shipwright [
+              #       "-march=znver2"
+              #       "-mtune=znver2"
+              #     ])
+              #   else
+              #     prev.shipwright;
+            in
+            {
               shipwright = pkgs.buildEnv {
                 name = prev.shipwright.name;
                 paths = [
-                (config.lib.nixGL.wrap prev.shipwright)
+                  (config.lib.nixGL.wrap original_package)
                 ];
                 extraOutputsToInstall = [
                   "man"
@@ -70,7 +89,8 @@ in
                   chmod 0555 $out/share/applications/soh.desktop
                 '';
               };
-          })
+            }
+          )
         ];
       })
     ]

nix/steam_deck/configuration/roles/sm64ex/default.nix

@@ -52,7 +52,24 @@ in
         };
 
         nixpkgs.overlays = [
-          (final: prev: {
+          (
+            final: prev:
+            let
+              optimizeWithFlags =
+                pkg: flags:
+                pkg.overrideAttrs (old: {
+                  NIX_CFLAGS_COMPILE = [ (old.NIX_CFLAGS_COMPILE or "") ] ++ flags;
+                });
+              original_package =
+                if config.me.optimizations.enable then
+                  (optimizeWithFlags prev.sm64ex [
+                    "-march=znver2"
+                    "-mtune=znver2"
+                  ])
+                else
+                  prev.sm64ex;
+            in
+            {
               sm64ex =
                 let
                   desktop_item = pkgs.makeDesktopItem {
@@ -70,7 +87,7 @@ in
                 pkgs.buildEnv {
                   name = prev.sm64ex.name;
                   paths = [
-                  (config.lib.nixGL.wrap prev.sm64ex)
+                    (config.lib.nixGL.wrap original_package)
                   ];
                   extraOutputsToInstall = [
                     "man"
@@ -83,7 +100,8 @@ in
                     install -m 444 -D "${./files/icon.png}" $out/share/pixmaps/sm64ex.png
                   '';
                 };
-          })
+            }
+          )
         ];
       })
     ]