uefi: improve doc

Author: phip1611

uefi/src/lib.rs

@@ -48,7 +48,8 @@
 //!   the Rust standard library. For example, methods that return a
 //!   `Vec` rather than filling a statically-sized array. This requires
 //!   a global allocator; you can use the `global_allocator` feature or
-//!   provide your own.
+//!   provide your own. This is independent of internal direct usages of the
+//!   UEFI boot service allocator which may happen anyway, where necessary.
 //! - `global_allocator`: Set [`allocator::Allocator`] as the global Rust
 //!   allocator. This is a simple allocator that relies on the UEFI pool
 //!   allocator. You can choose to provide your own allocator instead of

uefi/src/table/boot.rs

@@ -224,6 +224,12 @@ impl BootServices {
     /// Stores the current UEFI memory map in an UEFI-heap allocated buffer
     /// and returns a [`MemoryMap`].
     ///
+    /// # Parameters
+    ///
+    /// - `mt`: The memory type for the backing memory on the UEFI heap.
+    ///   Usually, this is [`MemoryType::LOADER_DATA`]. You can also use a
+    ///   custom type.
+    ///
     /// # Errors
     ///
     /// See section `EFI_BOOT_SERVICES.GetMemoryMap()` in the UEFI Specification