Move memory region structs to boot_info module

Author: phil-opp

src/binary/bios/memory_descriptor.rs

@@ -1,4 +1,4 @@
-use crate::{binary::legacy_memory_region::LegacyMemoryRegion, memory_region::MemoryRegionKind};
+use crate::{binary::legacy_memory_region::LegacyMemoryRegion, boot_info::MemoryRegionKind};
 use x86_64::PhysAddr;
 
 impl LegacyMemoryRegion for E820MemoryRegion {

src/binary/legacy_memory_region.rs

@@ -1,4 +1,4 @@
-use crate::memory_region::{MemoryRegion, MemoryRegionKind};
+use crate::boot_info::{MemoryRegion, MemoryRegionKind};
 use core::mem::MaybeUninit;
 use x86_64::{
     structures::paging::{FrameAllocator, PhysFrame, Size4KiB},

src/binary/mod.rs

@@ -1,6 +1,7 @@
-use crate::binary::legacy_memory_region::{LegacyFrameAllocator, LegacyMemoryRegion};
-use crate::boot_info::{BootInfo, FrameBuffer, FrameBufferInfo, TlsTemplate};
-use crate::memory_region::MemoryRegion;
+use crate::{
+    binary::legacy_memory_region::{LegacyFrameAllocator, LegacyMemoryRegion},
+    boot_info::{BootInfo, FrameBuffer, FrameBufferInfo, MemoryRegion, TlsTemplate},
+};
 use core::{
     mem::{self, MaybeUninit},
     slice,

src/binary/uefi/memory_descriptor.rs

@@ -1,4 +1,4 @@
-use crate::{binary::legacy_memory_region::LegacyMemoryRegion, memory_region::MemoryRegionKind};
+use crate::{binary::legacy_memory_region::LegacyMemoryRegion, boot_info::MemoryRegionKind};
 use uefi::table::boot::{MemoryDescriptor, MemoryType};
 use x86_64::PhysAddr;
 

src/boot_info.rs

@@ -1,4 +1,3 @@
-use crate::memory_region::MemoryRegion;
 use core::{ops, slice};
 
 /// This structure represents the information that the bootloader passes to the kernel.
@@ -104,6 +103,52 @@ impl From<MemoryRegions> for &'static mut [MemoryRegion] {
     }
 }
 
+/// Represent a physical memory region.
+#[derive(Debug, Copy, Clone, Eq, PartialEq)]
+#[repr(C)]
+pub struct MemoryRegion {
+    /// The physical start address of the region.
+    pub start: u64,
+    /// The physical end address (exclusive) of the region.
+    pub end: u64,
+    /// The memory type of the memory region.
+    ///
+    /// Only [`Usable`][MemoryRegionKind::Usable] regions can be freely used.
+    pub kind: MemoryRegionKind,
+}
+
+impl MemoryRegion {
+    /// Creates a new empty memory region (with length 0).
+    pub const fn empty() -> Self {
+        MemoryRegion {
+            start: 0,
+            end: 0,
+            kind: MemoryRegionKind::Bootloader,
+        }
+    }
+}
+
+/// Represents the different types of memory.
+#[derive(Debug, Copy, Clone, Eq, PartialEq)]
+#[non_exhaustive]
+#[repr(C)]
+pub enum MemoryRegionKind {
+    /// Unused conventional memory, can be used by the kernel.
+    Usable,
+    /// Memory mappings created by the bootloader, including the kernel and boot info mappings.
+    ///
+    /// This memory should _not_ be used by the kernel.
+    Bootloader,
+    /// An unknown memory region reported by the UEFI firmware.
+    ///
+    /// This should only be used if the UEFI memory type is known as usable.
+    UnknownUefi(u32),
+    /// An unknown memory region reported by the BIOS firmware.
+    ///
+    /// This should only be used if the BIOS memory type is known as usable.
+    UnknownBios(u32),
+}
+
 /// A pixel-based framebuffer that controls the screen output.
 #[derive(Debug)]
 #[repr(C)]

src/lib.rs

@@ -19,8 +19,6 @@ pub mod config;
 
 /// Contains the boot information struct sent by the bootloader to the kernel on startup.
 pub mod boot_info;
-/// Provides a memory region type that is used in the memory map of the boot info structure.
-pub mod memory_region;
 
 /// Contains the actual bootloader implementation ("bootloader as a binary").
 ///