Rework Hybrid MBR https://github.com/nix-community/disko/pull/168 (#508)

Add hybrid MBR functionality to the gpt type

disk-deactivate/disk-deactivate.jq

@@ -24,7 +24,7 @@ def remove:
 ;
 
 def deactivate:
-  if .type == "disk" then
+  if .type == "disk" or .type == "loop" then
     [
       # If this disk is a member of raid, stop that raid
       "md_dev=$(lsblk \(.path) -l -p -o type,name | awk 'match($1,\"raid.*\") {print $2}')",
@@ -54,7 +54,7 @@ def deactivate:
       "mdadm --stop \(.name)"
     ]
   else
-    []
+    ["echo Warning: unknown type '\(.type)'. Consider handling this in https://github.com/nix-community/disko/blob/master/disk-deactivate/disk-deactivate.jq"]
   end
 ;
 

example/hybrid-mbr.nix

@@ -0,0 +1,47 @@
+{disks ? ["/dev/sda"], ...}: {
+  disko.devices = {
+    disk = {
+      main = {
+        type = "disk";
+        device = builtins.elemAt disks 0;
+        content = {
+          type = "gpt";
+          efiGptPartitionFirst = false;
+          partitions = {
+            TOW-BOOT-FI = {
+              priority = 1;
+              type = "EF00";
+              size = "32M";
+              content = {
+                type = "filesystem";
+                format = "vfat";
+                mountpoint = null;
+              };
+              hybrid = {
+                mbrPartitionType = "0x0c";
+                mbrBootableFlag = false;
+              };
+            };
+            ESP = {
+              type = "EF00";
+              size = "512M";
+              content = {
+                type = "filesystem";
+                format = "vfat";
+                mountpoint = "/boot";
+              };
+            };
+            root = {
+              size = "100%";
+              content = {
+                type = "filesystem";
+                format = "ext4";
+                mountpoint = "/";
+              };
+            };
+          };
+        };
+      };
+    };
+  };
+}

lib/default.nix

@@ -84,9 +84,11 @@ let
         "${dev}${toString index}" # /dev/md/raid1 style
       else if match "/dev/mapper/.+" dev != null then
         "${dev}${toString index}" # /dev/mapper/vg-lv1 style
+      else if match "/dev/loop[[:digit:]]+" dev != null
+        then "${dev}p${toString index}" # /dev/mapper/vg-lv1 style
       else
         abort ''
-          ${dev} seems not to be a supported disk format. Please add this to disko in https://github.com/nix-community/disko/blob/master/types/default.nix
+          ${dev} seems not to be a supported disk format. Please add this to disko in https://github.com/nix-community/disko/blob/master/lib/default.nix
         '';
 
     /* get the index an item in a list

lib/types/gpt.nix

@@ -1,6 +1,7 @@
 { config, options, lib, diskoLib, parent, device, ... }:
 let
   sortedPartitions = lib.sort (x: y: x.priority < y.priority) (lib.attrValues config.partitions);
+  sortedHybridPartitions = lib.filter (p: p.hybrid != null) sortedPartitions;
 in
 {
   options = {
@@ -80,6 +81,35 @@ in
             '';
           };
           content = diskoLib.partitionType { parent = config; device = partition.config.device; };
+          hybrid = lib.mkOption {
+            type = lib.types.nullOr (lib.types.submodule ({name, ...} @ hp: {
+              options = {
+                mbrPartitionType = lib.mkOption {
+                  type = lib.types.nullOr lib.types.str;
+                  default = null;
+                  description = "MBR type code";
+                };
+                mbrBootableFlag = lib.mkOption {
+                  type = lib.types.bool;
+                  default = false;
+                  description = "Set the bootable flag (aka the active flag) on any or all of your hybridized partitions";
+                };
+                _create = diskoLib.mkCreateOption {
+                  inherit config options;
+                  default = ''
+                    ${lib.optionalString (hp.config.mbrPartitionType != null) ''
+                      sfdisk --label-nested dos --part-type ${parent.device} ${(toString partition.config._index)} ${hp.config.mbrPartitionType}
+                    ''}
+                    ${lib.optionalString hp.config.mbrBootableFlag ''
+                      sfdisk --label-nested dos --activate ${parent.device} ${(toString partition.config._index)}
+                    ''}
+                  '';
+                };
+              };
+            }));
+            default = null;
+            description = "Entry to add to the Hybrid MBR table";
+          };
           _index = lib.mkOption {
             internal = true;
             default = diskoLib.indexOf (x: x.name == partition.config.name) sortedPartitions 0;
@@ -89,6 +119,11 @@ in
       default = { };
       description = "Attrs of partitions to add to the partition table";
     };
+    efiGptPartitionFirst = lib.mkOption {
+      type = lib.types.bool;
+      default = true;
+      description = "Place EFI GPT (0xEE) partition first in MBR (good for GRUB)";
+    };
     _parent = lib.mkOption {
       internal = true;
       default = parent;
@@ -122,6 +157,20 @@ in
           ${lib.optionalString (partition.content != null) partition.content._create}
         '') sortedPartitions)}
 
+        ${
+          lib.optionalString (sortedHybridPartitions != [])
+          ("sgdisk -h "
+            + (lib.concatStringsSep ":" (map (p: (toString p._index)) sortedHybridPartitions))
+            + (
+              lib.optionalString (!config.efiGptPartitionFirst) ":EE "
+            )
+            + parent.device)
+        }
+        ${lib.concatMapStrings (p:
+            p.hybrid._create
+          )
+          sortedHybridPartitions}
+
       '';
     };
     _mount = diskoLib.mkMountOption {

tests/hybrid-mbr.nix

@@ -0,0 +1,11 @@
+{ pkgs ? import <nixpkgs> { }
+, diskoLib ? pkgs.callPackage ../lib { }
+}:
+diskoLib.testLib.makeDiskoTest {
+  inherit pkgs;
+  name = "hybrid-mbr";
+  disko-config = ../example/hybrid-mbr.nix;
+  extraTestScript = ''
+    machine.succeed("mountpoint /");
+  '';
+}