Sort and remove overlaps from memory map

Author: phil-opp

src/boot_info.rs

@@ -1,6 +1,6 @@
 use core::slice;
 
-use os_bootinfo::{E820MemoryRegion, MemoryMap, MemoryRegion};
+use os_bootinfo::{E820MemoryRegion, MemoryMap, MemoryRegion, MemoryRegionType};
 use usize_conversions::usize_from;
 use x86_64::VirtAddr;
 
@@ -14,5 +14,20 @@ pub(crate) fn create_from(memory_map_addr: VirtAddr, entry_count: u64) -> Memory
         memory_map.add_region(MemoryRegion::from(*region));
     }
 
+    memory_map.sort();
+
+    let mut iter = memory_map.iter_mut().peekable();
+    while let Some(region) = iter.next() {
+        if let Some(next) = iter.peek() {
+            if region.range.end > next.range.start {
+                if region.region_type == MemoryRegionType::Usable {
+                    region.range.end = next.range.start;
+                } else {
+                    panic!("two non-usable regions overlap: {:?} {:?}", region, next);
+                }
+            }
+        }
+    }
+
     memory_map
 }