I DONT KNOW WHAT IM DOING AND IM SCARED

src/kernel/arch/x86_64/mod.rs

@@ -4,4 +4,5 @@
 pub mod asm;
 pub mod gdt;
 pub mod interrupts;
+pub mod paging;
 pub mod serial;

src/kernel/arch/x86_64/paging.rs

@@ -0,0 +1,266 @@
+#![allow(dead_code)]
+
+use intbits::Bits;
+
+#[repr(packed)]
+pub struct PageMapLevel5 {
+    entries: [PageMapLevel5Entry; 512],
+}
+
+pub struct PageMapLevel5Entry {
+    value: u64,
+}
+
+impl PageMapLevel5Entry {
+    pub fn execute_disable(&self) -> bool {
+        self.value.bit(63)
+    }
+    pub fn present(&self) -> bool {
+        self.value.bit(0)
+    }
+    pub fn set_present(&mut self, present: bool) {
+        self.value.set_bit(0, present);
+    }
+    pub fn writable(&self) -> bool {
+        self.value.bit(1)
+    }
+    pub fn set_writable(&mut self, writable: bool) {
+        self.value.set_bit(1, writable);
+    }
+    pub fn user_accessible(&self) -> bool {
+        self.value.bit(2)
+    }
+    pub fn set_user_accessible(&mut self, accessible: bool) {
+        self.value.set_bit(2, accessible);
+    }
+    pub fn write_through(&self) -> bool {
+        self.value.bit(3)
+    }
+    pub fn set_write_through(&mut self, write_through: bool) {
+        self.value.set_bit(3, write_through);
+    }
+    pub fn cache_disable(&self) -> bool {
+        self.value.bit(4)
+    }
+    pub fn set_cache_disable(&mut self, cache_disable: bool) {
+        self.value.set_bit(4, cache_disable);
+    }
+    pub fn accessed(&self) -> bool {
+        self.value.bit(5)
+    }
+    pub fn set_accessed(&mut self, accessed: bool) {
+        self.value.set_bit(5, accessed);
+    }
+    pub fn physical_address(&self) -> usize {
+        self.value.bits(12..=51) as usize
+    }
+    pub fn set_physical_address(&mut self, address: u64) {
+        self.value &= 0xFFF0000000000FFF;
+        self.value |= (address & 0xFFFFFFFFFF) << 12;
+    }
+    pub fn available(&self) -> usize {
+        (self.value.bits(52..=62) << 4 & self.value.bits(8..=11) << 1 & self.value.bits(6..=6))
+            as usize
+    }
+}
+
+#[repr(packed)]
+pub struct PageMapLevel4 {
+    entries: [PageMapLevel4Entry; 512],
+}
+
+pub struct PageMapLevel4Entry {
+    value: u64,
+}
+
+impl PageMapLevel4Entry {
+    pub fn execute_disable(&self) -> bool {
+        self.value.bit(63)
+    }
+    pub fn present(&self) -> bool {
+        self.value.bit(0)
+    }
+    pub fn set_present(&mut self, present: bool) {
+        self.value.set_bit(0, present);
+    }
+    pub fn writable(&self) -> bool {
+        self.value.bit(1)
+    }
+    pub fn set_writable(&mut self, writable: bool) {
+        self.value.set_bit(1, writable);
+    }
+    pub fn user_accessible(&self) -> bool {
+        self.value.bit(2)
+    }
+    pub fn set_user_accessible(&mut self, accessible: bool) {
+        self.value.set_bit(2, accessible);
+    }
+    pub fn write_through(&self) -> bool {
+        self.value.bit(3)
+    }
+    pub fn set_write_through(&mut self, write_through: bool) {
+        self.value.set_bit(3, write_through);
+    }
+    pub fn cache_disable(&self) -> bool {
+        self.value.bit(4)
+    }
+    pub fn set_cache_disable(&mut self, cache_disable: bool) {
+        self.value.set_bit(4, cache_disable);
+    }
+    pub fn accessed(&self) -> bool {
+        self.value.bit(5)
+    }
+    pub fn set_accessed(&mut self, accessed: bool) {
+        self.value.set_bit(5, accessed);
+    }
+    pub fn physical_address(&self) -> usize {
+        self.value.bits(12..=51) as usize
+    }
+    pub fn set_physical_address(&mut self, address: u64) {
+        self.value &= 0xFFF0000000000FFF;
+        self.value |= (address & 0xFFFFFFFFFF) << 12;
+    }
+    pub fn set_pointer_table(&mut self, table: &PageDirectoryPointerTable) {
+        self.set_physical_address(&raw const table as u64);
+    }
+    pub fn available(&self) -> usize {
+        (self.value.bits(52..=62) << 4 & self.value.bits(8..=11) << 1 & self.value.bits(6..=6))
+            as usize
+    }
+}
+
+#[repr(packed)]
+pub struct PageDirectoryPointerTable {
+    entries: [*mut PageDirectory; 4],
+}
+
+pub struct PageDirectoryPointer {
+    value: u64
+}
+
+impl PageDirectoryPointer {
+    pub fn execute_disable(&self) -> bool {
+        self.value.bit(63)
+    }
+    pub fn present(&self) -> bool {
+        self.value.bit(0)
+    }
+    pub fn set_present(&mut self, present: bool) {
+        self.value.set_bit(0, present);
+    }
+    pub fn writable(&self) -> bool {
+        self.value.bit(1)
+    }
+    pub fn set_writable(&mut self, writable: bool) {
+        self.value.set_bit(1, writable);
+    }
+    pub fn user_accessible(&self) -> bool {
+        self.value.bit(2)
+    }
+    pub fn set_user_accessible(&mut self, accessible: bool) {
+        self.value.set_bit(2, accessible);
+    }
+    pub fn write_through(&self) -> bool {
+        self.value.bit(3)
+    }
+    pub fn set_write_through(&mut self, write_through: bool) {
+        self.value.set_bit(3, write_through);
+    }
+    pub fn cache_disable(&self) -> bool {
+        self.value.bit(4)
+    }
+    pub fn set_cache_disable(&mut self, cache_disable: bool) {
+        self.value.set_bit(4, cache_disable);
+    }
+    pub fn accessed(&self) -> bool {
+        self.value.bit(5)
+    }
+    pub fn set_accessed(&mut self, accessed: bool) {
+        self.value.set_bit(5, accessed);
+    }
+    pub fn physical_address(&self) -> *mut PageDirectory {
+        self.value.bits(12..=51) as *mut PageDirectory
+    }
+    pub fn set_physical_address(&mut self, address: u64) {
+        self.value &= 0xFFF0000000000FFF;
+        self.value |= (address & 0xFFFFFFFFFF) << 12;
+    }
+    pub fn set_page_directory(&mut self, dir: &PageDirectory) {
+        self.set_physical_address(&raw const dir as u64);
+    }
+    pub fn available(&self) -> usize {
+        (self.value.bits(52..=62) << 4 & self.value.bits(8..=11) << 1 & self.value.bits(6..=6))
+            as usize
+    }
+}
+
+pub struct PageDirectory {
+    entries: [PageDirectoryEntry; 512],
+}
+
+pub struct PageDirectoryEntry {
+    value: u64,
+}
+
+impl PageDirectoryEntry {
+    pub fn execute_disable(&self) -> bool {
+        self.value.bit(63)
+    }
+    pub fn present(&self) -> bool {
+        self.value.bit(0)
+    }
+    pub fn set_present(&mut self, present: bool) {
+        self.value.set_bit(0, present);
+    }
+    pub fn writable(&self) -> bool {
+        self.value.bit(1)
+    }
+    pub fn set_writable(&mut self, writable: bool) {
+        self.value.set_bit(1, writable);
+    }
+    pub fn user_accessible(&self) -> bool {
+        self.value.bit(2)
+    }
+    pub fn set_user_accessible(&mut self, accessible: bool) {
+        self.value.set_bit(2, accessible);
+    }
+    pub fn write_through(&self) -> bool {
+        self.value.bit(3)
+    }
+    pub fn set_write_through(&mut self, write_through: bool) {
+        self.value.set_bit(3, write_through);
+    }
+    pub fn cache_disable(&self) -> bool {
+        self.value.bit(4)
+    }
+    pub fn set_cache_disable(&mut self, cache_disable: bool) {
+        self.value.set_bit(4, cache_disable);
+    }
+    pub fn accessed(&self) -> bool {
+        self.value.bit(5)
+    }
+    pub fn set_accessed(&mut self, accessed: bool) {
+        self.value.set_bit(5, accessed);
+    }
+    pub fn physical_address(&self) -> usize {
+        self.value.bits(12..=51) as usize
+    }
+    pub fn set_physical_address(&mut self, address: u64) {
+        self.value &= 0xFFF0000000000FFF;
+        self.value |= (address & 0xFFFFFFFFFF) << 12;
+    }
+    pub fn available(&self) -> usize {
+        (self.value.bits(52..=62) << 4 & self.value.bits(8..=11) << 1 & self.value.bits(6..=6))
+            as usize
+    }
+}
+
+#[repr(align(4096))]
+pub struct PageTable {
+    entries: [PageTableEntry; 512],
+}
+
+#[repr(packed)]
+pub struct PageTableEntry {
+    value: u64,
+}

src/kernel/constants.rs

@@ -5,6 +5,7 @@ use crate::format;
 use crate::log::LogLevel;
 use crate::memory::alloc::string::String;
 
+#[allow(dead_code)]
 pub static INITRAMFS_DEFAULT_PATH: &str = "/boot/initramfs.tar.lzma";
 
 pub static LOG_DEFAULT_LEVEL: LogLevel = LogLevel::Info;

src/kernel/main.rs

@@ -22,6 +22,7 @@ mod util;
 use core::arch::asm;
 
 use arch::x86_64::gdt::gdt;
+use arch::x86_64::paging::{self, PageDirectory, PageMapLevel4Entry, PageMapLevel5, PageMapLevel5Entry};
 #[cfg(target_arch = "x86_64")]
 use arch::x86_64::serial::Serialport;
 
@@ -29,12 +30,11 @@ use arch::asm::*;
 use boot::{modules::*, params, *};
 use constants::*;
 use log::*;
-use memory::{MEMMAP_REQUEST, HHDM_RESPONSE};
 use memory::alloc::{format, string::*, vec};
+use memory::{HHDM_RESPONSE, MEMMAP_REQUEST};
 use params::*;
 
 use intbits::{self, Bits};
-use limine::file::File;
 use limine::memory_map::EntryType;
 #[allow(unused_imports)]
 use lzma_rs::lzma_decompress;
@@ -113,27 +113,6 @@ unsafe extern "C" fn main() -> ! {
         log_trace!("{log_msg}")
     }
 
-    let irfs_path = {
-        if let Some(key) = PARAMS.get("-initramfs") {
-            key
-        } else {
-            INITRAMFS_DEFAULT_PATH
-        }
-    };
-
-    log_trace!("Boot: initramfs path requested: {irfs_path}");
-    let _initramfs = {
-        let mut result: Option<&File> = None;
-        for file in MODULE_RESPONSE.modules() {
-            if file.path().to_string_lossy() == irfs_path {
-                result = Some(file);
-                log_info!("Boot: initramfs found");
-            }
-        }
-        result
-    }
-    .expect("initramfs not found in modules list");
-
     // Panic if this is absent. It's needed to set up the GDT and paging
     let mmap_response = MEMMAP_REQUEST
         .get_response()
@@ -223,9 +202,22 @@ unsafe extern "C" fn main() -> ! {
             cr3.bits(12..=31)
         };
         log_trace!("Boot: Physical address of page directory: 0x{:x}", pd_addr);
-        log_trace!("Boot: Virtual address of page directory: 0x{:x}", pd_addr + HHDM_RESPONSE.offset());
-        log_trace!("Boot: GDT: 0x{:x} bytes @ 0x{:x}", unsafe { gdt().0 }, unsafe { gdt().1} );
-        log_trace!("Boot: GDT: 0x{:x}", unsafe { *((gdt().1 + 0x0) as *const u64) })
+        log_trace!(
+            "Boot: Virtual address of page directory: 0x{:x}",
+            pd_addr + HHDM_RESPONSE.offset()
+        );
+        log_trace!(
+            "Boot: GDT: 0x{:x} bytes @ 0x{:x}",
+            unsafe { gdt().0 },
+            unsafe { gdt().1 }
+        );
+        log_trace!("Boot: GDT: 0x{:x}", unsafe {
+            *((gdt().1 + 0x0) as *const u64)
+        });
+        log_trace!(
+            "Size of page directory: {}",
+            size_of::<PageMapLevel4Entry>()
+        );
     }
 
     panic!("Bailing");

src/kernel/memory.rs

@@ -5,7 +5,10 @@
 
 use enumflags2::*;
 use lazy_static::lazy_static;
-use limine::{request::{ExecutableAddressRequest, HhdmRequest, MemoryMapRequest}, response::HhdmResponse};
+use limine::{
+    request::{ExecutableAddressRequest, HhdmRequest, MemoryMapRequest},
+    response::HhdmResponse,
+};
 
 use core::alloc::{Allocator, Layout};
 use talc::*;
@@ -26,7 +29,9 @@ pub static MEMMAP_REQUEST: MemoryMapRequest = limine::request::MemoryMapRequest:
 pub static HHDM_REQUEST: HhdmRequest = limine::request::HhdmRequest::new();
 
 lazy_static! {
-    pub static ref HHDM_RESPONSE: &'static HhdmResponse = HHDM_REQUEST.get_response().expect("Did not get HHDM response from bootloader");
+    pub static ref HHDM_RESPONSE: &'static HhdmResponse = HHDM_REQUEST
+        .get_response()
+        .expect("Did not get HHDM response from bootloader");
 }
 
 static mut ARENA: [u8; 10000] = [0; 10000];