kernel: comment

kernel/src/x86_64/paging.rs

@@ -99,6 +99,10 @@ impl RootPageTable {
         let end = align_up(phy.end.0, PAGE_SIZE as u64);
         let size = end - start;
 
+        // split the mapping into regions of 1GB, 2MB, and 4KB pages, depending on the alignment of the virtual address and the size of the mapping.
+        // insert the regions with `flags` into the page table, creating new tables with permissions R/W/X as necessary.
+        // if any leaf-entries are encountered, undo the mapping and return an error.
+
         match size {
             Self::ONE_GB.. if is_aligned(virt.0, Self::ONE_GB) => {}
             Self::TWO_MB.. if is_aligned(virt.0, Self::TWO_MB) => {}