feat: support for removing properties directly in FDT

Author: m4tx

src/fdt_mut/node.rs

@@ -44,6 +44,37 @@ impl FdtNodeMut<'_> {
         None
     }
 
+    /// Removes a property from this node by its name.
+    ///
+    /// This is a convenience method that finds a property by name and calls
+    /// [`FdtPropertyMut::remove`] on it.
+    ///
+    /// Returns `true` if the property was present and successfully removed,
+    /// `false` otherwise.
+    ///
+    /// # Examples
+    ///
+    /// ```
+    /// use dtoolkit::fdt_mut::FdtMut;
+    /// use dtoolkit::{Node, Property};
+    ///
+    /// # let mut dtb = include_bytes!("../../tests/dtb/test_traversal.dtb").to_vec();
+    /// let mut fdt = FdtMut::new(&mut dtb).unwrap();
+    /// let mut node = fdt.find_node_mut("/a/b/c").unwrap();
+    /// assert!(node.property("prop").is_some());
+    /// assert!(node.remove_property("prop"));
+    /// assert!(node.property("prop").is_none());
+    /// assert!(!node.remove_property("prop"));
+    /// ```
+    pub fn remove_property(&mut self, name: &str) -> bool {
+        if let Some(prop) = self.property_mut(name) {
+            prop.remove();
+            true
+        } else {
+            false
+        }
+    }
+
     /// Returns a mutable iterator over the properties of this node.
     pub fn properties_mut(&mut self) -> FdtPropMutIter<'_> {
         FdtPropMutIter {

src/fdt_mut/property.rs

@@ -141,6 +141,37 @@ impl FdtPropertyMut<'_> {
             .expect("Fdt should be valid");
         FdtProperty { name, value }
     }
+
+    /// Removes the property by overwriting its structure with `NOP` tags.
+    ///
+    /// The memory previously occupied by this property will be replaced with
+    /// `NOP` tags, rendering it invisible to Device Tree iterators
+    /// without requiring data to be shifted.
+    ///
+    /// # Examples
+    ///
+    /// ```
+    /// use dtoolkit::fdt_mut::FdtMut;
+    /// use dtoolkit::{Node, Property};
+    ///
+    /// # let mut dtb = include_bytes!("../../tests/dtb/test_traversal.dtb").to_vec();
+    /// let mut fdt = FdtMut::new(&mut dtb).unwrap();
+    /// let mut node = fdt.find_node_mut("/a/b/c").unwrap();
+    /// let prop = node.property_mut("prop").unwrap();
+    /// prop.remove();
+    /// assert!(node.property("prop").is_none());
+    /// ```
+    pub fn remove(self) {
+        let start = self.prop_offset;
+        let end = Fdt::align_tag_offset(self.value_offset + self.len);
+        let nop_bytes = FDT_NOP.to_be_bytes();
+
+        let mut offset = start;
+        while offset < end {
+            self.data.data[offset..offset + FDT_TAGSIZE].copy_from_slice(&nop_bytes);
+            offset += FDT_TAGSIZE;
+        }
+    }
 }
 
 impl Display for FdtPropertyMut<'_> {

tests/fdt_mut.rs

@@ -79,3 +79,37 @@ fn modify_property_shrink_and_grow() {
     let err = prop_mut.set_value(long_val).unwrap_err();
     assert_eq!(err, FdtMutError::ShiftingRequired);
 }
+
+#[test]
+fn remove_property_via_handle() {
+    let dtb = include_bytes!("dtb/test_props.dtb");
+    let mut data = dtb.to_vec();
+
+    let mut fdt_mut = FdtMut::new(&mut data).unwrap();
+    let mut node_mut = fdt_mut.find_node_mut("/test-props").unwrap();
+    let prop_mut = node_mut.property_mut("str-prop").unwrap();
+    prop_mut.remove();
+
+    let fdt = Fdt::new(&data).unwrap();
+    let node = fdt.find_node("/test-props").unwrap();
+    assert!(node.property("str-prop").is_none());
+    // Verify other properties remain
+    assert!(node.property("u32-prop").is_some());
+}
+
+#[test]
+fn remove_property_via_node() {
+    let dtb = include_bytes!("dtb/test_props.dtb");
+    let mut data = dtb.to_vec();
+
+    let mut fdt_mut = FdtMut::new(&mut data).unwrap();
+    let mut node_mut = fdt_mut.find_node_mut("/test-props").unwrap();
+
+    assert!(node_mut.remove_property("str-prop"));
+    assert!(!node_mut.remove_property("str-prop")); // Idempotent check
+
+    let fdt = Fdt::new(&data).unwrap();
+    let node = fdt.find_node("/test-props").unwrap();
+    assert!(node.property("str-prop").is_none());
+    assert!(node.property("u32-prop").is_some());
+}