uefi: remove code duplication

The existing code duplication is just temporary until the old API
is deleted. Nevertheless, it is nicer to have this conversion close
to the actual type.

Author: phip1611

uefi/src/boot.rs

@@ -23,7 +23,6 @@ use uefi_raw::table::boot::InterfaceType;
 
 #[cfg(doc)]
 use crate::proto::device_path::LoadedImageDevicePath;
-use uefi::proto::BootPolicy;
 #[cfg(feature = "alloc")]
 use {alloc::vec::Vec, uefi::ResultExt};
 
@@ -995,29 +994,7 @@ pub fn load_image(parent_image_handle: Handle, source: LoadImageSource) -> Resul
     let bt = boot_services_raw_panicking();
     let bt = unsafe { bt.as_ref() };
 
-    let boot_policy;
-    let device_path;
-    let source_buffer;
-    let source_size;
-    match source {
-        LoadImageSource::FromBuffer { buffer, file_path } => {
-            // Boot policy is ignored when loading from source buffer.
-            boot_policy = BootPolicy::ExactMatch;
-
-            device_path = file_path.map(|p| p.as_ffi_ptr()).unwrap_or(ptr::null());
-            source_buffer = buffer.as_ptr();
-            source_size = buffer.len();
-        }
-        LoadImageSource::FromDevicePath {
-            device_path: file_path,
-            boot_policy: new_boot_policy,
-        } => {
-            boot_policy = new_boot_policy;
-            device_path = file_path.as_ffi_ptr();
-            source_buffer = ptr::null();
-            source_size = 0;
-        }
-    };
+    let (boot_policy, device_path, source_buffer, source_size) = source.to_ffi_params();
 
     let mut image_handle = ptr::null_mut();
     unsafe {

uefi/src/table/boot.rs

@@ -8,6 +8,7 @@ use super::Revision;
 use crate::data_types::PhysicalAddress;
 use crate::mem::memory_map::*;
 use crate::proto::device_path::DevicePath;
+use crate::proto::device_path::FfiDevicePath;
 use crate::proto::loaded_image::LoadedImage;
 use crate::proto::media::fs::SimpleFileSystem;
 use crate::proto::{BootPolicy, Protocol, ProtocolPointer};
@@ -841,29 +842,7 @@ impl BootServices {
         parent_image_handle: Handle,
         source: LoadImageSource,
     ) -> uefi::Result<Handle> {
-        let boot_policy;
-        let device_path;
-        let source_buffer;
-        let source_size;
-        match source {
-            LoadImageSource::FromBuffer { buffer, file_path } => {
-                // Boot policy is ignored when loading from source buffer.
-                boot_policy = BootPolicy::ExactMatch;
-
-                device_path = file_path.map(|p| p.as_ffi_ptr()).unwrap_or(ptr::null());
-                source_buffer = buffer.as_ptr();
-                source_size = buffer.len();
-            }
-            LoadImageSource::FromDevicePath {
-                device_path: file_path,
-                boot_policy: new_boot_policy,
-            } => {
-                boot_policy = new_boot_policy;
-                device_path = file_path.as_ffi_ptr();
-                source_buffer = ptr::null();
-                source_size = 0;
-            }
-        };
+        let (boot_policy, device_path, source_buffer, source_size) = source.to_ffi_params();
 
         let mut image_handle = ptr::null_mut();
         unsafe {
@@ -1422,6 +1401,44 @@ pub enum LoadImageSource<'a> {
     },
 }
 
+impl<'a> LoadImageSource<'a> {
+    /// Returns the raw FFI parameters for `load_image`.
+    #[must_use]
+    pub(crate) fn to_ffi_params(
+        &self,
+    ) -> (
+        BootPolicy,
+        *const FfiDevicePath,
+        *const u8, /* buffer */
+        usize,     /* buffer length */
+    ) {
+        let boot_policy;
+        let device_path;
+        let source_buffer;
+        let source_size;
+        match self {
+            LoadImageSource::FromBuffer { buffer, file_path } => {
+                // Boot policy is ignored when loading from source buffer.
+                boot_policy = BootPolicy::ExactMatch;
+
+                device_path = file_path.map(|p| p.as_ffi_ptr()).unwrap_or(ptr::null());
+                source_buffer = buffer.as_ptr();
+                source_size = buffer.len();
+            }
+            LoadImageSource::FromDevicePath {
+                device_path: d_path,
+                boot_policy: b_policy,
+            } => {
+                boot_policy = *b_policy;
+                device_path = d_path.as_ffi_ptr();
+                source_buffer = ptr::null();
+                source_size = 0;
+            }
+        };
+        (boot_policy, device_path, source_buffer, source_size)
+    }
+}
+
 /// RAII guard for task priority level changes
 ///
 /// Will automatically restore the former task priority level when dropped.