uefi: add MemoryMap::raw

Author: phip1611

uefi/CHANGELOG.md

@@ -17,6 +17,9 @@
 - Re-exported `CapsuleFlags`.
 - One can now specify in `TimeError` what fields of `Time` are outside its valid
   range. `Time::is_valid` has been updated accordingly.
+- `MemoryMap::as_raw` which provides raw access to the memory map. This is for
+  example useful if you create your own Multiboot2 bootloader that embeds the
+  EFI mmap in a Multiboot2 boot information structure.
 
 ## Changed
 - `SystemTable::exit_boot_services` is now `unsafe`. See that method's

uefi/src/table/boot.rs

@@ -1729,6 +1729,12 @@ impl MemoryMapBackingMemory {
         self.0.as_ptr().cast()
     }
 
+    /// Returns a slice to the underlying memory.
+    #[must_use]
+    pub fn as_slice(&self) -> &[u8] {
+        unsafe { self.0.as_ref() }
+    }
+
     /// Returns a mutable slice to the underlying memory.
     #[must_use]
     pub fn as_mut_slice(&mut self) -> &mut [u8] {
@@ -1972,6 +1978,15 @@ impl MemoryMap {
 
         Some(desc)
     }
+
+    /// Provides access to the raw memory map.
+    ///
+    /// This is for example useful if you want to embed the memory map into
+    /// another data structure, such as a Multiboot2 boot information.
+    #[must_use]
+    pub fn as_raw(&self) -> (&[u8], MemoryMapMeta) {
+        (self.buf.as_slice(), self.meta)
+    }
 }
 
 impl core::ops::Index<usize> for MemoryMap {