Recursive map the P4 table

src/arch/x86_64/boot.asm

@@ -42,6 +42,11 @@ start:
     jmp gdt64.code:long_mode_start
 
 setup_page_tables:
+    ; recursive map P4
+    mov eax, p4_table
+    or eax, 0b11 ; present + writable
+    mov [p4_table + 511 * 8], eax
+
     ; map first P4 entry to P3 table
     mov eax, p3_table
     or eax, 0b11 ; present + writable

src/memory/paging/table.rs

@@ -2,6 +2,8 @@ use memory::paging::entry::*;
 use memory::paging::ENTRY_COUNT;
 use core::ops::{Index, IndexMut};
 
+pub const P4: *mut Table = 0xffffffff_fffff000 as *mut _;
+
 pub struct Table {
     entries: [Entry; ENTRY_COUNT],
 }