From e071c2468067c77e8672755082cc4006e33d11ee Mon Sep 17 00:00:00 2001
From: Philipp Oppermann <dev@phil-opp.com>
Date: Wed, 9 Dec 2015 00:10:50 +0100
Subject: [PATCH] Recursive map the P4 table

---
 src/arch/x86_64/boot.asm   | 5 +++++
 src/memory/paging/table.rs | 2 ++
 2 files changed, 7 insertions(+)

diff --git a/src/arch/x86_64/boot.asm b/src/arch/x86_64/boot.asm
index 2f5295d7..4abb2899 100644
--- a/src/arch/x86_64/boot.asm
+++ b/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
diff --git a/src/memory/paging/table.rs b/src/memory/paging/table.rs
index 0a1935e2..41d92742 100644
--- a/src/memory/paging/table.rs
+++ b/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],
 }