uefi: Add LoadFile and LoadFile2

Author: phip1611

uefi/CHANGELOG.md

@@ -15,6 +15,8 @@
   the implementations `MemoryMapRef`, `MemoryMapRefMut`, and `MemoryMapOwned`.
   This comes with some changes. Read below. We recommend to directly use the
   implementations instead of the traits.
+- Added `LoadFile` and `LoadFile2` which abstracts over the `LOAD_FILE` and
+  `LOAD_FILE2` protocols.
 
 ## Changed
 - **Breaking:** `uefi::helpers::init` no longer takes an argument.

uefi/src/proto/media/load_file.rs

@@ -0,0 +1,91 @@
+//! LoadFile and LoadFile2 protocols.
+
+use crate::mem::make_boxed;
+use crate::proto::device_path::DevicePath;
+use crate::proto::unsafe_protocol;
+use crate::StatusExt;
+#[cfg(all(feature = "alloc", feature = "unstable"))]
+use alloc::alloc::Global;
+#[cfg(feature = "alloc")]
+use alloc::boxed::Box;
+use uefi::Result;
+use uefi_raw::protocol::media::{LoadFile2Protocol, LoadFileProtocol};
+
+/// TODO.
+#[derive(Debug)]
+#[repr(transparent)]
+#[unsafe_protocol(LoadFileProtocol::GUID)]
+pub struct LoadFile(LoadFileProtocol);
+
+impl LoadFile {
+    /// TODO.
+    #[cfg(feature = "alloc")]
+    pub fn load_file<'a>(
+        &mut self,
+        file_path: &DevicePath,
+        boot_policy: bool,
+    ) -> Result<Box<[u8]>> {
+        log::debug!("hello");
+        let this = core::ptr::addr_of_mut!(*self).cast();
+
+        let fetch_data_fn = |buf: &'a mut [u8]| {
+            log::debug!("hello");
+            let mut size = buf.len();
+            let status = unsafe {
+                (self.0.load_file)(
+                    this,
+                    file_path.as_ffi_ptr().cast(),
+                    boot_policy,
+                    &mut size,
+                    buf.as_mut_ptr().cast(),
+                )
+            };
+            status.to_result_with_err(|_| Some(size)).map(|_| buf)
+        };
+
+        #[cfg(not(feature = "unstable"))]
+        let file: Box<[u8]> = make_boxed::<[u8], _>(fetch_data_fn)?;
+
+        #[cfg(feature = "unstable")]
+        let file = make_boxed::<[u8], _, _>(fetch_data_fn, Global)?;
+
+        Ok(file)
+    }
+}
+
+/// TODO.
+#[derive(Debug)]
+#[repr(transparent)]
+#[unsafe_protocol(LoadFile2Protocol::GUID)]
+pub struct LoadFile2(LoadFile2Protocol);
+
+impl LoadFile2 {
+    /// TODO.
+    pub fn load_file<'a>(&mut self, file_path: &DevicePath) -> Result<Box<[u8]>> {
+        let this = core::ptr::addr_of_mut!(*self).cast();
+
+        let fetch_data_fn = |buf: &'a mut [u8]| {
+            log::debug!("hello");
+            let mut size = buf.len();
+            let status = unsafe {
+                (self.0.load_file)(
+                    this,
+                    file_path.as_ffi_ptr().cast(),
+                    false, /* always false - see spec */
+                    &mut size,
+                    buf.as_mut_ptr().cast(),
+                )
+            };
+            log::debug!("hello");
+            status.to_result_with_err(|_| Some(size)).map(|_| buf)
+        };
+
+        #[cfg(not(feature = "unstable"))]
+        let file: Box<[u8]> = make_boxed::<[u8], _>(fetch_data_fn)?;
+
+        #[cfg(feature = "unstable")]
+        let file = make_boxed::<[u8], _, _>(fetch_data_fn, Global)?;
+
+        Ok(file)
+    }
+}

uefi/src/proto/media/mod.rs

@@ -9,4 +9,5 @@ pub mod file;
 pub mod block;
 pub mod disk;
 pub mod fs;
+pub mod load_file;
 pub mod partition;