feat(paging): enabling write protection

Signed-off-by: Julien CLEMENT <julien.clement@epita.fr>

src/lib.rs

@@ -34,6 +34,7 @@ pub fn init<A>(frame_allocator: &mut A, boot_info: &BootInformation)
     vga::change_color(ColorCode::new(Color::LightCyan, Color::Black));
     println!("Starting init");
     enable_nxe_bit();
+    enable_write_protect_bit();
     memory::kernel_remap(frame_allocator, boot_info);
     gdt::init_gdt();
     interrupts::init_idt();
@@ -46,6 +47,14 @@ fn enable_nxe_bit() {
     unsafe { Efer::update(|efer| *efer |= EferFlags::NO_EXECUTE_ENABLE) }
 }
 
+
+fn enable_write_protect_bit() {
+    println!("Enabling write protection bit");
+    use x86_64::registers::control::{Cr0, Cr0Flags};
+
+    unsafe { Cr0::write(Cr0::read() | Cr0Flags::WRITE_PROTECT) };
+}
+
 fn get_frame_allocator(multiboot_info_addr: usize) -> memory::AreaFrameAllocator {
     let boot_info = unsafe { multiboot2::load(multiboot_info_addr) };
     let memory_map_tag = boot_info.memory_map_tag().expect("Memory map tag required");

src/memory/paging/mod.rs

@@ -47,8 +47,6 @@ pub fn kernel_remap<A>(allocator: &mut A, boot_info: &BootInformation)
                 // section is not loaded to memory
                 continue;
             }
-            println!("mapping section at addr: {:#x}, size: {:#x}",
-                section.addr, section.size);
             assert!(section.start_address() % PAGE_SIZE == 0,
                     "sections need to be page aligned");