.

flake.nix

@@ -45,7 +45,13 @@
               content = {
                 type = "gpt";
                 partitions = {
+                  bios_boot = {
+                    size = "2MiB";
+                    type = "EF02"; # BIOS boot partition (unformatted)
+                    content = null; # No filesystem
+                  };
                   ESP = {
+                    # Optional for hybrid, but harmless
                     size = "512M";
                     type = "EF00";
                     content = {
@@ -54,7 +60,6 @@
                       mountpoint = "/boot";
                     };
                   };
-
                   root = {
                     size = "100%";
                     content = {
@@ -102,16 +107,12 @@
               };
             };
           };
+
           boot.loader = {
-            efi = {
-              canTouchEfiVariables = true;
-              efiSysMountPoint = "/boot";
-            };
             grub = {
               enable = true;
-              device = "nodev"; # For UEFI; installs to ESP
-              efiSupport = true;
-              useOSProber = false; # Avoid scanning sdb
+              device = "/dev/sda"; # Install only on sda (avoids sdb)
+              useOSProber = false; # Don't scan other disks
             };
           };