provisioning: Add helpers for decoding partition table types

Signed-off-by: Ikey Doherty <[email protected]>

Author: ikeycode

crates/provisioning/src/types.rs

@@ -4,10 +4,13 @@
 
 use std::fmt;
 
-use kdl::KdlValue;
+use kdl::{KdlEntry, KdlValue};
 
 use crate::Error;
 
+mod partition_table;
+pub use partition_table::*;
+
 /// The type of a KDL value
 #[derive(Debug)]
 pub enum KdlType {
@@ -48,3 +51,7 @@ impl fmt::Display for KdlType {
         }
     }
 }
+
+pub trait FromKdlProperty<'a>: Sized {
+    fn from_kdl_property(entry: &'a KdlEntry) -> Result<Self, Error>;
+}

crates/provisioning/src/types/partition_table.rs

@@ -0,0 +1,52 @@
+// SPDX-FileCopyrightText: Copyright © 2025 Serpent OS Developers
+//
+// SPDX-License-Identifier: MPL-2.0
+
+use std::{fmt, str::FromStr};
+
+use crate::kdl_value_to_string;
+
+use super::FromKdlProperty;
+
+/// The type of partition table to create
+#[derive(Debug, PartialEq)]
+pub enum PartitionTableType {
+    /// GUID Partition Table
+    Gpt,
+
+    /// Master Boot Record
+    Msdos,
+}
+
+impl fmt::Display for PartitionTableType {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        match self {
+            Self::Gpt => f.write_str("gpt"),
+            Self::Msdos => f.write_str("msdos"),
+        }
+    }
+}
+
+impl FromStr for PartitionTableType {
+    type Err = crate::Error;
+
+    /// Attempt to convert a string to a partition table type
+    fn from_str(value: &str) -> Result<Self, Self::Err> {
+        match value {
+            "gpt" => Ok(Self::Gpt),
+            "msdos" => Ok(Self::Msdos),
+            _ => Err(crate::Error::UnknownVariant),
+        }
+    }
+}
+
+impl FromKdlProperty<'_> for PartitionTableType {
+    fn from_kdl_property(entry: &kdl::KdlEntry) -> Result<Self, crate::Error> {
+        let value = kdl_value_to_string(entry)?;
+        let v = value.parse().map_err(|_| crate::UnsupportedValue {
+            at: entry.span(),
+            advice: Some("'gpt' and 'mbr' are supported".into()),
+        })?;
+        Ok(v)
+    }
+}