Implemented Paging! Moved Kernel to 0x100000, Moved TSS above 1M, Moved V86 to 0x8000, Moved Usermode test to 0x400000, Moved lots of things!

paging.c

@@ -0,0 +1,50 @@
+#include "paging.h"
+
+uint32_t page_directory[1024] __attribute__((aligned(4096)));
+uint32_t first_page_table[1024] __attribute__((aligned(4096))); // 0x00000000 - 0x00400000
+uint32_t second_page_table[1024] __attribute__((aligned(4096))); // 0x00400000 - 0x00800000
+
+void enable_paging() {
+    asm(
+        "mov %%eax, %%cr3\n"
+        "mov %%cr0, %%eax\n"
+        "or $0x80000001, %%eax\n"
+        "mov %%eax, %%cr0\n"
+    ::"a"(page_directory));
+}
+
+void init_paging() {
+    for (int i = 0; i < 1024; i++)
+        // Supervisor, R/W, Not Present
+        page_directory[i] = 2;
+
+    // First Page Table
+    // First MB: Real Mode
+    {
+        int i;
+        // Up to 0xC0000
+        // TODO make some areas here Read Only
+        for (i = 0;i < 16*0xC; i++)
+            // User, R/W, Present
+            first_page_table[i] = (i * 0x1000) |4|2|1;
+        // Remainder of first MB BIOS Area (writable?)
+        for (;i < 256; i++)
+            // User, R/W, Present
+            first_page_table[i] = (i * 0x1000) |4|2|1;
+    }
+    // Next 3MB: Kernel
+    for (int i = 256; i < 1024; i++)
+        // Supervisor, R/W, Present
+        first_page_table[i] = (i * 0x1000) |2|1;
+
+    // Usermode Page Table
+    for (int i = 0; i < 1024; i++)
+        // User, R/W, Present
+        second_page_table[i] = (i * 0x1000 + 0x400000) |4|2|1;
+
+    // User, R/W, Present
+    page_directory[0] = ((uintptr_t)first_page_table)|4|2|1;
+    page_directory[1] = ((uintptr_t)second_page_table)|4|2|1;
+
+    enable_paging();
+}