replaced grub with systemd

hosts/acheron/iso.nix

@@ -1,7 +1,13 @@
 # ── acheron rescue / installer ISO ─────────────────────────────
 # ISO for VM / server deployment. Supports both BIOS (SeaBIOS) and
 # UEFI boot for maximum Proxmox compatibility.
-{ config, pkgs, pkgs-unstable, lib, ... }: {
+{
+  config,
+  pkgs,
+  pkgs-unstable,
+  lib,
+  ...
+}: {
   imports = [
     ../iso/default.nix
   ];

hosts/buildbox/configuration.nix

@@ -17,12 +17,10 @@
     inputs.home-manager.nixosModules.default
   ];
 
-  # Bootloader. disko derives boot.loader.grub.devices automatically
-  # from the EF02 (BIOS Boot) partition in ./disko-config.nix, so we
-  # only enable GRUB here — do NOT set grub.devices, or it will merge
-  # with disko's value and trigger the "duplicated devices in
-  # mirroredBoots" assertion.
-  boot.loader.grub.enable = lib.mkDefault true;
+  # Bootloader.
+  boot.loader.systemd-boot.enable = true;
+  boot.loader.efi.canTouchEfiVariables = true;
+  boot.loader.systemd-boot.removableDeviceAssistant = true;
 
   nix.settings.experimental-features = ["nix-command" "flakes"];
 

hosts/buildbox/disko-config.nix

@@ -13,16 +13,18 @@
         content = {
           type = "gpt";
           partitions = {
-            # GRUB's core.img lives here on GPT/BIOS systems (GPT leaves no
-            # gap after the MBR, so grub-install needs an EF02 partition).
-            # No `content` block — this partition holds raw GRUB boot code,
-            # not a filesystem. disko also derives boot.loader.grub.devices
-            # from this partition automatically.
-            # See: https://github.com/nix-community/disko/blob/master/example/gpt-bios-compat.nix
-            boot = {
-              size = "1M";
-              type = "EF02";
-              attributes = [0];
+            # Modern EFI System Partition (ESP)
+            ESP = {
+              priority = 1;
+              name = "ESP";
+              size = "1G"; # 1GB gives plenty of space for multiple NixOS kernels/generations
+              type = "EF00";
+              content = {
+                type = "filesystem";
+                format = "vfat";
+                mountpoint = "/boot";
+                mountOptions = ["umask=0077"];
+              };
             };
             root = {
               size = "100%";

hosts/ender-ml/configuration.nix

@@ -20,8 +20,10 @@
   boot.kernelPackages = pkgs-unstable.linuxKernel.packages.linux_zen;
 
   # Bootloader.
-  boot.loader.grub.enable = lib.mkDefault true;
-  boot.loader.grub.devices = ["nodev"];
+  boot.loader.systemd-boot.enable = true;
+  boot.loader.efi.canTouchEfiVariables = true;
+  boot.loader.systemd-boot.removableDeviceAssistant = true;
+
 
   nix.settings.experimental-features = ["nix-command" "flakes"];
 

hosts/ender-ml/disko-config.nix

@@ -9,10 +9,23 @@
     disk = {
       main = {
         type = "disk";
-        device = "/dev/vda";
+        device = "/dev/sda";
         content = {
           type = "gpt";
           partitions = {
+            # Modern EFI System Partition (ESP)
+            ESP = {
+              priority = 1;
+              name = "ESP";
+              size = "1G"; # 1GB gives plenty of space for multiple NixOS kernels/generations
+              type = "EF00";
+              content = {
+                type = "filesystem";
+                format = "vfat";
+                mountpoint = "/boot";
+                mountOptions = ["umask=0077"];
+              };
+            };
             root = {
               size = "100%";
               content = {