libflashrom: Add layout "exclude" API

Layouts can be expensive to derive (reading from flash), so we might
want to reuse a layout for different purposes. Today, it's not possible
to undo a flashrom_layout_include_region() operation (to, say, operate
on a different region). Add such an API.

Change-Id: I7ea3e0674f25e34bf2cfc8f464ae7ca1c1a3fbfd
Signed-off-by: Brian Norris <briannorris@chromium.org>
Reviewed-on: https://review.coreboot.org/c/flashrom/+/76005
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Edward O'Callaghan <quasisec@chromium.org>
Reviewed-by: Nikolai Artemiev <nartemiev@google.com>

bindings/rust/libflashrom/src/lib.rs

@@ -879,6 +879,32 @@ impl Layout {
         }
     }
 
+    /// Exclude a region
+    ///
+    /// # Errors
+    ///
+    /// This function will return an error if the region is not a valid CString,
+    /// or if libflashrom returns an error.
+    pub fn exclude_region(&mut self, region: &str) -> std::result::Result<(), RegionError> {
+        let err = {
+            let region = CString::new(region)?;
+            unsafe {
+                libflashrom_sys::flashrom_layout_exclude_region(
+                    self.layout.as_mut(),
+                    region.as_ptr(),
+                )
+            }
+        };
+        if err != 0 {
+            Err(RegionError::ErrorCode(ErrorCode {
+                function: "flashrom_layout_exclude_region",
+                code: err,
+            }))
+        } else {
+            Ok(())
+        }
+    }
+
     /// Get the [`Range`] for the given region
     ///
     /// # Errors