Merge pull request #216 from rust-osdev/efi-mmap

multiboot2: fix handling of efi memory map

multiboot2/Cargo.toml

@@ -6,7 +6,7 @@ Multiboot2-compliant bootloaders, such as GRUB. It supports all tags from the
 specification including full support for the sections of ELF files. This library
 is `no_std` and can be used in a Multiboot2-kernel.
 """
-version = "0.20.0"
+version = "0.20.1"
 authors = [
     "Philipp Oppermann <dev@phil-opp.com>",
     "Calvin Lee <cyrus296@gmail.com>",

multiboot2/Changelog.md

@@ -1,6 +1,12 @@
 # CHANGELOG for crate `multiboot2`
 
-## Unreleased
+## 0.20.1 (2024-05-26)
+
+- fixed the handling of `EFIMemoryMapTag` and `EFIMemoryAreaIter`
+- **BREAKING** Fixed wrong creation of `EFIMemoryMapTag`.
+  `EFIMemoryMapTag::new` was replaced by `EFIMemoryMapTag::new_from_descs` and
+  `EFIMemoryMapTag::new_from_map`.
+- `ModuleTag::new`'s `end` parameter now must be bigger than `start`.
 
 ## 0.20.0 (2024-05-01)
 

multiboot2/src/lib.rs

@@ -77,8 +77,8 @@ pub use end::EndTag;
 pub use framebuffer::{FramebufferColor, FramebufferField, FramebufferTag, FramebufferType};
 pub use image_load_addr::ImageLoadPhysAddrTag;
 pub use memory_map::{
-    BasicMemoryInfoTag, EFIMemoryAreaType, EFIMemoryDesc, EFIMemoryMapTag, MemoryArea,
-    MemoryAreaType, MemoryAreaTypeId, MemoryMapTag,
+    BasicMemoryInfoTag, EFIMemoryAreaType, EFIMemoryAttribute, EFIMemoryDesc, EFIMemoryMapTag,
+    MemoryArea, MemoryAreaType, MemoryAreaTypeId, MemoryMapTag,
 };
 pub use module::{ModuleIter, ModuleTag};
 pub use ptr_meta::Pointee;
@@ -302,7 +302,10 @@ impl<'a> BootInformation<'a> {
         // If the EFIBootServicesNotExited is present, then we should not use
         // the memory map, as it could still be in use.
         match self.get_tag::<EFIBootServicesNotExitedTag>() {
-            Some(_tag) => None,
+            Some(_tag) => {
+                log::debug!("The EFI memory map is present but the UEFI Boot Services Not Existed Tag is present. Returning None.");
+                None
+            }
             None => self.get_tag::<EFIMemoryMapTag>(),
         }
     }
@@ -1450,15 +1453,15 @@ mod tests {
     #[cfg_attr(miri, ignore)]
     fn efi_memory_map() {
         #[repr(C, align(8))]
-        struct Bytes([u8; 72]);
+        struct Bytes([u8; 80]);
         // test that the EFI memory map is detected.
         let bytes: Bytes = Bytes([
-            72, 0, 0, 0, // size
+            80, 0, 0, 0, // size
             0, 0, 0, 0, // reserved
             17, 0, 0, 0, // EFI memory map type
-            56, 0, 0, 0, // EFI memory map size
+            64, 0, 0, 0, // EFI memory map size
             48, 0, 0, 0, // EFI descriptor size
-            1, 0, 0, 0, // EFI descriptor version, don't think this matters.
+            1, 0, 0, 0, // EFI descriptor version
             7, 0, 0, 0, // Type: EfiConventionalMemory
             0, 0, 0, 0, // Padding
             0, 0, 16, 0, // Physical Address: should be 0x100000
@@ -1469,6 +1472,8 @@ mod tests {
             0, 0, 0, 0, // Extension of pages
             0, 0, 0, 0, // Attributes of this memory range.
             0, 0, 0, 0, // Extension of attributes
+            0, 0, 0, 0, // More padding to extend the efi mmap to `desc_size`.
+            0, 0, 0, 0, // padding/alignment for end tag
             0, 0, 0, 0, // end tag type.
             8, 0, 0, 0, // end tag size.
         ]);