Memory map dump

src/main.rs

@@ -64,6 +64,8 @@ fn kernel_main(boot_info: &'static BootInfo) -> ! {
     use x86_64::structures::paging::MapperAllSizes;
     use x86_64::VirtAddr;
 
+    serial_println!("Memory map: {:#?}", boot_info.memory_map);
+
     let phys_mem_offset = VirtAddr::new(boot_info.physical_memory_offset);
     // new: initialize a mapper
     let mut frame_allocator =

src/memory.rs

@@ -79,12 +79,14 @@ impl BootInfoFrameAllocator {
         // map each region to its address range
         let addr_ranges = usable_regions.map(|r| r.range.start_addr()..r.range.end_addr());
         // transform to an iterator of frame start addresses
-        let frame_addresses = addr_ranges.flat_map(|r| r.step_by(4096));
+        let frame_addresses = addr_ranges.flat_map(|r| r.step_by(4096)); // TODO Magic number, this is where 4k pages are enforced
                                                                          // create `PhysFrame` types from the start addresses
         let frames = frame_addresses.map(|addr| PhysFrame::containing_address(PhysAddr::new(addr)));
         frames
     }
 }
+
+// We only allocate 4k pages
 unsafe impl FrameAllocator<Size4KiB> for BootInfoFrameAllocator {
     fn allocate_frame(&mut self) -> Option<UnusedPhysFrame> {
         let frame = self.usable_frames().nth(self.next);