From 6edeba8fe208fb019aec00fdc72b97407a8078d3 Mon Sep 17 00:00:00 2001
From: Loic Guegan <manzerbredes@mailbox.org>
Date: Sun, 11 Apr 2021 20:53:06 +0200
Subject: Enable paging

---
 src/utils/paging.c | 31 +++++++++++++++++++++++++++++++
 1 file changed, 31 insertions(+)
 create mode 100644 src/utils/paging.c

(limited to 'src/utils/paging.c')

diff --git a/src/utils/paging.c b/src/utils/paging.c
new file mode 100644
index 0000000..b1f462f
--- /dev/null
+++ b/src/utils/paging.c
@@ -0,0 +1,31 @@
+#include "paging.h"
+
+void paging_enable(){
+    int *page_dir=(int*)PAGING_DIR_LOCATION;
+    int *page_table=(int*)PAGING_TABLE_LOCATION;
+
+    // Init page directory
+    for(int i=0;i<1024;i++)
+        page_dir[i]=0;
+    page_dir[0]=(int)page_table;
+    page_dir[0] |=7; // Permissions
+
+    // Init page table 0
+    int addr_offset=0;
+    for(int i=0;i<1024;i++){
+        page_table[i]=addr_offset;
+        page_table[i]|=7; // Permission
+        addr_offset+=4096; // 4Ko pages
+    }
+
+    // Turns on paging
+    asm(
+        "movl %0, %%eax       \n\t"
+        "movl %%eax, %%cr3    \n\t" // Configure page table location
+        "movl %%cr0, %%eax    \n\t"
+        "orl %1, %%eax        \n\t"
+        "movl %%eax, %%cr0    \n\t" // Turn on paging
+        :: "i" (PAGING_DIR_LOCATION), "i" (PAGING_CR0_BIT)
+    );
+
+}
\ No newline at end of file
-- 
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