partition: introduce more settings for EFI size

src/modules/partition/partition.conf

@@ -11,12 +11,22 @@ efiSystemPartition:     "/boot/efi"
 # This optional setting specifies the size of the EFI system partition.
 # If nothing is specified, the default size of 300MiB will be used.
 #
-# This size applies both to automatic partitioning and the checks
-# during manual partitioning. A minimum of 32MiB is enforced,
-# 300MiB is the default, M is treated as MiB, and if you really want
-# one-million (10^6) bytes, use MB.
+# 300MiB is the default, and when writing quantities here, M is treated
+# as MiB, and if you really want one-million (10^6) bytes, use MB.
 #
-# efiSystemPartitionSize:     300M
+# Going below the *recommended* size is allowed, but the user will
+# get a warning that it might not work. Going below the *minimum*
+# size is not allowed and the user will be told it will not work.
+#
+# Both quantities must be at least 32MiB, this is enforced by the EFI
+# spec. If minimum is not specified, it defaults to the recommended
+# size. Distro's that allow more user latitude can set the minimum lower.
+efi:
+    recommendedSize:    300MiB
+    minimumSize:        32MiB
+
+# This is a deprecated alias of efi.recommendedSize
+# efiSystemPartitionSize:          300MiB
 
 # This optional setting specifies the name of the EFI system partition (see
 # PARTLABEL; gpt only; requires KPMCore >= 4.2.0).

src/modules/partition/partition.schema.yaml

@@ -8,9 +8,16 @@ additionalProperties: false
 type: object
 properties:
     efiSystemPartition: { type: string }  # Mount point
-    efiSystemPartitionSize: { type: string }
+    efiSystemPartitionSize: { type: string } # Deprecated alias of efi.recommendedSize
     efiSystemPartitionName: { type: string }
 
+    efi:
+        type: object
+        properties:
+            recommendedSize: { type: string }
+            minimumSize: { type: string }
+        additionalProperties: false
+
     userSwapChoices: { type: array, items: { type: string, enum: [ none, reuse, small, suspend, file ] } }
     # ensureSuspendToDisk: { type: boolean, default: true }  # Legacy
     # neverCreateSwap: { type: boolean, default: false }  # Legacy