Megacommit to move some memory code into kernel crate

README.md

@@ -10,7 +10,7 @@ git clone https://git.zxq5.dev/OsDev/FoundryOS.git
 * latest rust nightly release
 * all necessary rust components installed
 * xorriso: creates ISO images to be booted from.
-* (Optional / Recommended) Qemu: to run the kernel. (this may be packaged as qemu-desktop)
+* (Optional / Recommended) qemu: to run the kernel. (this may be packaged as qemu-desktop)
 * (Optional) GDB: for debugging the kernel.
 
 ```sh
@@ -20,12 +20,33 @@ rustup component add rust-src
 rustup component add llvm-tools-preview
 ```
 
-## Building & Running in Qemu:
+## Building & Running in qemu
 ```sh
 cargo run
 ```
 
-## Running in GDB:
+## Running in GDB
 ```sh
 USE_GDB=1 cargo run
 ```
+
+## Build errors
+
+If you see a qemu error like this:
+
+```
+qemu-system-x86_64: -drive if=pflash,format=raw,readonly=on,file=<...>/OVMF_CODE.fd: Could not open '<...>/OVMF_CODE.fd': No such file or directory
+```
+
+Simply delete the ./build directory and try to rebuild the program. Using the runner script or `cargo run` will download the required files for you, this is because the script only checks for the presence of one file and not the VARS file.
+
+Alternatively, you may disable using a UEFI firmware with qemu like so:
+```sh
+USE_LEGACY_BIOS=1 cargo run
+```
+
+## Debugging
+
+See [debugging](docs/Debugging/DEBUGGING.md) for some help with this, including commands to help with disassembly.
+
+If you have any other issues, feel free to create an issue or a PR.

config/limine.conf

@@ -1,5 +1,5 @@
 # Timeout in seconds that Limine will use before automatically booting.
-timeout: 1
+timeout: 0
 
 # The entry name that will be displayed in the boot menu.
 /foundry-os

debug.txt

@@ -0,0 +1,17 @@
+ Running kernel in debug mode.
+info: Creating build directory structure
+info: Copying files to ISO root
+  Copying: /home/fantasypvp/Projects/OSdev/FoundryOS/build/target/x86_64-kernel/debug/kernel to /home/fantasypvp/Projects/OSdev/FoundryOS/build/iso_root/boot/kernel
+  Copying: /home/fantasypvp/Projects/OSdev/FoundryOS/config/limine.conf to /home/fantasypvp/Projects/OSdev/FoundryOS/build/iso_root/boot/limine/limine.conf
+  Copying: /home/fantasypvp/Projects/OSdev/FoundryOS/build/limine/limine-bios-cd.bin to /home/fantasypvp/Projects/OSdev/FoundryOS/build/iso_root/boot/limine/
+  Copying: /home/fantasypvp/Projects/OSdev/FoundryOS/build/limine/limine-uefi-cd.bin to /home/fantasypvp/Projects/OSdev/FoundryOS/build/iso_root/boot/limine/
+  Copying: /home/fantasypvp/Projects/OSdev/FoundryOS/build/limine/limine-bios.sys to /home/fantasypvp/Projects/OSdev/FoundryOS/build/iso_root/boot/limine/
+  Copying: /home/fantasypvp/Projects/OSdev/FoundryOS/build/limine/BOOTX64.EFI to /home/fantasypvp/Projects/OSdev/FoundryOS/build/iso_root/EFI/BOOT/
+  Copying: /home/fantasypvp/Projects/OSdev/FoundryOS/build/limine/BOOTIA32.EFI to /home/fantasypvp/Projects/OSdev/FoundryOS/build/iso_root/EFI/BOOT/
+Building: bootable ISO image
+info: Installing Limine bootloader
+info: KVM acceleration enabled
+info: Running OS in QEMU...
+[=3h[=3h[=3hBdsDxe: loading Boot0001 "UEFI QEMU DVD-ROM QM00005 " from PciRoot(0x0)/Pci(0x1F,0x2)/Sata(0x2,0xFFFF,0x0)
+BdsDxe: starting Boot0001 "UEFI QEMU DVD-ROM QM00005 " from PciRoot(0x0)/Pci(0x1F,0x2)/Sata(0x2,0xFFFF,0x0)
+map worked!got apic base

docs/Debugging/DEBUGGING.md

@@ -0,0 +1,16 @@
+# Debugging the Kernel
+
+Here we will add some helpful tips on debugging the kernel.
+
+## Disassembling a public function
+
+To disassemble a public function, first we need a symbol in the public symbol table, so start by making the function fully public (including any parent modules). Do this as though you are trying to make a public function for a library crate (this includes the `kernel` crate). Simply mark the function and any parent modules as public, up until the point of [lib.rs (kernel link)](../../kernel/src/lib.rs).
+
+Then, we need to find the specific demangled symbol to disassemble, because the default objdump output can be very verbose.
+
+```sh
+# Change as required, I pipe to less and /SEARCH FOR FUNCTION HERE.
+nm --demangle ./build/target/x86_64-kernel/debug/kernel | less
+# Now just paste the symbol where it says YOUR_SYMBOL_HERE and profit. Use -Mintel for Intel assembly syntax.
+objdump -Matt --source --line-numbers --visualize-jumps ./build/target/x86_64-kernel/debug/kernel --demangle=rust --disassemble="YOUR_SYMBOL_HERE"
+```

kernel/src/arch/x86_64/apic/mod.rs

@@ -0,0 +1,113 @@
+#![allow(unused)] // TODO: Remove this when ready.
+use core::arch::x86_64::__cpuid;
+
+use x86_64::{
+    PhysAddr, VirtAddr,
+    structures::paging::{Mapper, Size4KiB},
+};
+
+use crate::serial_print;
+
+use super::{cpu::model_specific_registers::*, mem::memmap::PHYSICAL_MEMORY_OFFSET};
+
+const IA32_APIC_BASE_MSR: u32 = 0x1b;
+const IA32_APIC_BASE_MSR_BSP: u64 = 0x100;
+const IA32_APIC_BASE_MSR_ENABLE: u64 = 0x800;
+const IA32_APIC_BASE_MSR_DISABLE: u64 = !IA32_APIC_BASE_MSR_ENABLE;
+
+const CPUID_FEAT_EDX_APIC: u64 = 1 << 9; // the cpuid instruction will return this flag if it supports APIC
+
+// const APIC_VIRTUAL_ADDRESS: Lazy<VirtAddr> = Lazy::new(|| {
+//     let apic_base = get_apic_base();
+//     let virt_addr = unsafe { phys_to_virt(apic_base) };
+
+//     virt_addr
+// });
+
+fn set_apic_base_enable(apic: PhysAddr) {
+    let rax = (apic.as_u64() & 0xfffff0000) | IA32_APIC_BASE_MSR_ENABLE;
+    cpu_set_msr(IA32_APIC_BASE_MSR, rax);
+}
+
+fn set_apic_base_disable(apic: PhysAddr) {
+    let rax = (apic.as_u64() & 0xfffff0000) & IA32_APIC_BASE_MSR_DISABLE;
+    cpu_set_msr(IA32_APIC_BASE_MSR, rax);
+}
+
+fn get_apic_base() -> PhysAddr {
+    let mut value: u64 = 0;
+    cpu_get_msr(IA32_APIC_BASE_MSR, &mut value);
+    PhysAddr::new(value & 0xfffff0000)
+}
+
+fn write_apic_register(apic_base: &VirtAddr, reg: u8, value: u32) {
+    let apic_base = apic_base.as_u64();
+    let reg_addr = (apic_base & 0xFFFFF0000) + reg as u64;
+    unsafe { *(reg_addr as *mut u32) = value };
+}
+
+fn read_apic_register(apic_base: &VirtAddr, reg: u8) -> u32 {
+    let apic_base = apic_base.as_u64();
+
+    serial_print!("got apic base");
+
+    let reg_addr = (apic_base & 0xFFFFF0000) + reg as u64;
+    unsafe { *(reg_addr as *const u32) }
+}
+
+pub fn check_apic() -> bool {
+    let res = unsafe { __cpuid(1) };
+    res.edx as u64 & CPUID_FEAT_EDX_APIC != 0
+}
+
+#[inline(always)]
+unsafe fn phys_to_virt(phys: PhysAddr) -> VirtAddr {
+    let phys = phys.as_u64();
+    phys.checked_add(*PHYSICAL_MEMORY_OFFSET).map_or_else(
+        || {
+            serial_print!("THIS IS A PROBLEM");
+            panic!("overflow")
+        },
+        |virt| {
+            serial_print!("map worked!");
+            VirtAddr::new(virt)
+        },
+    )
+}
+
+pub fn enable_apic(
+    _mapper: &mut impl Mapper<Size4KiB>,
+    // TODO: Fix this function.
+    // frame_allocator: &mut FoundryOSFrameAllocator,
+) {
+    unimplemented!();
+
+    // let apic_phys_addr = get_apic_base();
+    // set_apic_base_enable(apic_phys_addr);
+    // map virt address of apic
+
+    // let apic_virt = unsafe { phys_to_virt(apic_phys_addr) };
+    // let page: Page<Size4KiB> = Page::containing_address(apic_virt);
+    // let frame: PhysFrame<Size4KiB> = PhysFrame::containing_address(apic_phys_addr);
+    // let flags: PageTableFlags = PageTableFlags::PRESENT | PageTableFlags::WRITABLE;
+
+    // unsafe {
+    //     match mapper.map_to(page, frame, flags, frame_allocator) {
+    //         Ok(_) => {}
+    //         Err(why) => panic!("failed to map apic: {:?}", why),
+    //     }
+    // }
+
+    // // FIXME: this causes a page fault
+    // // TODO: map to virtual memor
+
+    // let reg = read_apic_register(&apic_virt, 0xF0);
+
+    // serial_print!("ok2");
+
+    // write_apic_register(&apic_virt, 0xF0, reg | 0x100);
+}
+
+pub struct Apic {}
+
+pub enum ApicVector {}

kernel/src/arch/x86_64/cpu.rs

@@ -0,0 +1,26 @@
+pub mod model_specific_registers {
+    use core::arch::x86_64::__cpuid;
+    use spin::Lazy;
+    use x86_64::registers::model_specific::Msr;
+
+    const _CPUID_FLAG_MSR: u32 = 1 << 5;
+    static _EDX: Lazy<u32> = Lazy::new(|| unsafe { __cpuid(1).edx });
+
+    pub fn _cpu_has_msr() -> bool {
+        *_EDX & _CPUID_FLAG_MSR != 0
+    }
+
+    pub fn cpu_get_msr(msr: u32, value: &mut u64) {
+        let msr = Msr::new(msr);
+        unsafe {
+            *value = msr.read();
+        }
+    }
+
+    pub fn cpu_set_msr(msr: u32, value: u64) {
+        let mut msr = Msr::new(msr);
+        unsafe {
+            msr.write(value);
+        }
+    }
+}

kernel/src/arch/x86_64/interrupts.rs

@@ -1,8 +1,8 @@
+// use libk::drivers::mem::{FRAME_ALLOCATOR, OFFSET_PAGE_TABLE};
 use libk::prelude::*;
-use x86_64::registers::control::Cr2;
+use pic8259::ChainedPics;
 use x86_64::structures::idt::{InterruptDescriptorTable, InterruptStackFrame, PageFaultErrorCode};
 
-use pic8259::ChainedPics;
 use spin::{Lazy, Mutex};
 
 use super::gdt;
@@ -51,12 +51,22 @@ impl InterruptIndex {
 
 pub fn init_idt() {
     IDT.load();
+}
+
+pub fn enable_pic() {
     unsafe {
         PICS.lock().initialize();
         PICS.lock().write_masks(0xfc, 0xff);
     }
 }
 
+#[expect(unused)]
+pub fn disable_pic() {
+    unsafe {
+        PICS.lock().disable();
+    }
+}
+
 extern "x86-interrupt" fn breakpoint_handler(stack_frame: InterruptStackFrame) {
     serial_println!("Exception: Breakpoint\n{:#?}", stack_frame);
     println_log!("Exception: Breakpoint\n{:#?}", stack_frame);
@@ -112,13 +122,32 @@ extern "x86-interrupt" fn timer_interrupt_handler(_stack_frame: InterruptStackFr
 }
 
 extern "x86-interrupt" fn page_fault_handler(
-    stack_frame: InterruptStackFrame,
-    error_code: PageFaultErrorCode,
+    _stack_frame: InterruptStackFrame,
+    _error_code: PageFaultErrorCode,
 ) {
-    serial_println!("Exception: Page Fault");
-    serial_println!("Accessed Address: {:?}", Cr2::read());
-    serial_println!("Error Code: {:?}", error_code);
-    serial_println!("{:#?}", stack_frame);
+    todo!("Get this working again.")
+    // serial_println!("Exception: Page Fault");
+    // serial_println!("Accessed Address: {:?}", Cr2::read());
+    // serial_println!("Error Code: {:?}", error_code);
+    // serial_println!("{:#?}", stack_frame);
 
-    crate::hcf();
+    // if let Some(frame_allocator) = FRAME_ALLOCATOR.get() {
+    //     let mut f = frame_allocator.lock();
+
+    //     let frame = f.allocate_frame().unwrap();
+    //     let flags = PageTableFlags::PRESENT | PageTableFlags::WRITABLE;
+    //     let page: Page<Size4KiB> = Page::containing_address(Cr2::read().unwrap());
+
+    //     unsafe {
+    //         let mut mapper = OFFSET_PAGE_TABLE.get().unwrap().lock();
+
+    //         match mapper.map_to(page, frame, flags, &mut *f) {
+    //             Ok(_) => {}
+    //             Err(why) => panic!("failed to map page: {:?}", why),
+    //         }
+    //     }
+    //     MapperFlushAll::new().flush_all();
+    // } else {
+    //     panic!("failed to get frame allocator");
+    // }
 }

kernel/src/arch/x86_64/mem/memmap.rs

@@ -14,6 +14,10 @@ static MEMORY_MAP_REQUEST: MemoryMapRequest = MemoryMapRequest::new();
 #[unsafe(link_section = ".requests")]
 static HIGHER_HALF_DIRECT_MAP_REQUEST: HhdmRequest = HhdmRequest::new();
 
+#[used]
+#[unsafe(link_section = ".requests")]
+static KERNEL_ADDRESS_REQUEST: KernelAddressRequest = KernelAddressRequest::new();
+
 /// ```rs
 /// let virt_addr = phys_addr + offset;
 /// let phys_addr = virt_addr - offset; // (given VA is in the HHDM). Do not use for executable code.
@@ -25,10 +29,6 @@ pub static PHYSICAL_MEMORY_OFFSET: Lazy<u64> = Lazy::new(|| {
         .offset()
 });
 
-#[used]
-#[unsafe(link_section = ".requests")]
-static KERNEL_ADDRESS_REQUEST: KernelAddressRequest = KernelAddressRequest::new();
-
 /// Converts virtual addresses in the kernel to a physical address like this:
 /// ```rs
 /// let phys_addr = virt_addr - virtual_base + physical_base;

kernel/src/arch/x86_64/mem/mod.rs

@@ -0,0 +1,2 @@
+pub mod memmap;
+pub mod pmm;

kernel/src/arch/x86_64/memory.rs

@@ -1,141 +0,0 @@
-// use lib_alloc::allocator::FoundryAllocator;
-use limine::{memory_map::EntryType, response::MemoryMapResponse};
-use x86_64::{
-    PhysAddr,
-    VirtAddr,
-    // addr,
-    registers::control::Cr3,
-    structures::paging::{
-        // page_table::FrameError,
-        FrameAllocator,
-        OffsetPageTable,
-        PageTable,
-        PhysFrame,
-        Size4KiB,
-    },
-};
-
-/// Returns a mutable reference to the current level 4 page table.
-///
-/// # Safety
-///
-/// The caller must ensure that the level 4 page table is not modified
-/// simultaneously. The caller must also ensure that the physical memory offset
-/// is correct, to ensure that the correct virtual address is constructed.
-unsafe fn active_l4_table(physical_memory_offset: VirtAddr) -> &'static mut PageTable {
-    let (level_4_frame, _) = Cr3::read();
-
-    let phys_addr = level_4_frame.start_address();
-    let virt = phys_addr.as_u64() + physical_memory_offset.as_u64();
-    unsafe { &mut *(virt as *mut PageTable) }
-}
-
-/// Initializes the `OffsetPageTable` for the current CPU architecture.
-///
-/// # Safety
-///
-/// This function must be called only once and should be called before any
-/// memory operations are performed that rely on virtual memory management.
-/// The provided `physical_memory_offset` must be accurate to ensure correct
-/// translation of physical addresses.
-///
-/// # Parameters
-///
-/// - `physical_memory_offset`: The offset to convert physical addresses to
-///   virtual addresses in the higher-half direct map.
-///
-/// # Returns
-///
-/// Returns an `OffsetPageTable` that allows for manipulation of the page
-/// tables for the current CPU architecture.
-pub unsafe fn init(physical_memory_offset: VirtAddr) -> OffsetPageTable<'static> {
-    unsafe {
-        let l4_table = active_l4_table(physical_memory_offset);
-        OffsetPageTable::new(l4_table, physical_memory_offset)
-    }
-}
-
-pub struct FoundryOSFrameAllocator {
-    memory_map: &'static MemoryMapResponse,
-    next: usize,
-}
-
-impl FoundryOSFrameAllocator {
-    /// Creates a new `FoundryOSFrameAllocator` from a memory map.
-    ///
-    /// This function takes a reference to a `MemoryMapResponse` and initializes a
-    /// `FoundryOSFrameAllocator` with it. The `next` field is set to 0, indicating that
-    /// the first frame to be allocated is the first frame in the memory map.
-    pub const unsafe fn init(memory_map: &'static MemoryMapResponse) -> Self {
-        Self {
-            memory_map,
-            next: 0,
-        }
-    }
-
-    /// An iterator over all usable frames in the memory map.
-    ///
-    /// Yields one `PhysFrame` for each available 4KiB frame in the memory map.
-    ///
-    /// This function is used to allocate frames for the pagemap.
-    fn usable_frames(&self) -> impl Iterator<Item = PhysFrame> + use<> {
-        let regions = self.memory_map.entries().iter();
-        let usable_regions = regions.filter(|region| region.entry_type == EntryType::USABLE);
-
-        let addr_ranges = usable_regions.map(|region| region.base..region.base + region.length);
-
-        let frame_addresses = addr_ranges.flat_map(|r| r.step_by(4096));
-
-        frame_addresses.map(|addr| PhysFrame::from_start_address(PhysAddr::new(addr)).unwrap())
-    }
-}
-
-unsafe impl FrameAllocator<Size4KiB> for FoundryOSFrameAllocator {
-    /// Allocates a frame from the list of usable frames.
-    ///
-    /// This function returns the next available `PhysFrame` from the memory map,
-    /// if one exists. Once a frame is allocated, the internal counter is incremented
-    /// to point to the next frame for future allocations.
-    ///
-    /// # Returns
-    ///
-    /// - `Some(PhysFrame)`: If a usable frame is available.
-    /// - `None`: If there are no more usable frames to allocate.
-    fn allocate_frame(&mut self) -> Option<PhysFrame> {
-        let frame = self.usable_frames().nth(self.next);
-        self.next += 1;
-        frame
-    }
-}
-
-// pub unsafe fn translate_addr(addr: VirtAddr, physical_memory_offset: VirtAddr) -> Option<PhysAddr> {
-//     translate_addr_inner(addr, physical_memory_offset)
-// }
-
-// fn translate_addr_inner(addr: VirtAddr, physical_memory_offset: VirtAddr) -> Option<PhysAddr> {
-//     let (l4_table_frame, _) = Cr3::read();
-
-//     let table_indexes = [
-//         addr.p4_index(),
-//         addr.p3_index(),
-//         addr.p2_index(),
-//         addr.p1_index(),
-//     ];
-//     let mut frame = l4_table_frame;
-
-//     for &i in &table_indexes {
-//         let virt = physical_memory_offset + frame.start_address().as_u64();
-//         let table_ptr: *const PageTable = virt.as_ptr();
-//         let table = unsafe { &*table_ptr };
-
-//         let entry = &table[i];
-
-//         frame = match entry.frame() {
-//             Ok(frame) => frame,
-//             Err(FrameError::FrameNotPresent) => return None,
-//             Err(FrameError::HugeFrame) => panic!("huge frames are not supported!"),
-//         };
-//     }
-
-//     Some(frame.start_address() + u64::from(addr.page_offset()))
-// }

kernel/src/arch/x86_64/mod.rs

@@ -1,7 +1,5 @@
+pub mod apic;
+pub mod cpu;
 pub mod gdt;
-
 pub mod interrupts;
-
-pub mod memory;
-
-pub mod memmap;
+pub mod mem;

kernel/src/lib.rs

@@ -13,14 +13,14 @@
 
 extern crate alloc;
 
+// use arch::x86_64::apic::enable_apic;
 use core::arch::asm;
+// use libk::drivers::mem::pmm;
 use limine::BaseRevision;
 
-use libk::drivers::kalloc::allocator::init_heap;
+// use libk::drivers::alloc::allocator::init_heap;
 use libk::prelude::*;
 
-use x86_64::VirtAddr;
-
 mod arch;
 
 /// Sets the base revision to the latest revision supported by the crate.
@@ -56,9 +56,9 @@ pub fn boot() -> Result<(), &'static str> {
         return Err("base revision not supported");
     }
 
-    use arch::x86_64::{gdt, interrupts, memmap, memory};
+    use arch::x86_64::{gdt, interrupts, mem::memmap};
 
-    let memory_map = memmap::get_memory_map();
+    let _memory_map = memmap::get_memory_map();
 
     print_log!("    Initialising Serial... ");
     if libk::drivers::io::serial::init().is_err() {
@@ -75,21 +75,34 @@ pub fn boot() -> Result<(), &'static str> {
     interrupts::init_idt();
     println_log!("[Success]");
 
-    print_log!("    Setting Up Page Table... ");
-    let mut frame_allocator = unsafe { memory::FoundryOSFrameAllocator::init(memory_map) };
+    print_log!("    Initialising Memory Subsystem... ");
+    // let physical_memory_offset = VirtAddr::new(*memmap::PHYSICAL_MEMORY_OFFSET);
+    // pmm::init_page_table(physical_memory_offset);
     println_log!("[Success]");
 
-    print_log!("    Initialising Memory Subsystem... ");
-    let physical_memory_offset = VirtAddr::new(*memmap::PHYSICAL_MEMORY_OFFSET);
-    let mut l4_table = unsafe { memory::init(physical_memory_offset) };
+    print_log!("    Setting Up Page Table... ");
+    // pmm::init_frame_allocator(memory_map);
     println_log!("[Success]");
 
     print_log!("    Initialising Heap... ");
-    if init_heap(&mut l4_table, &mut frame_allocator).is_err() {
-        return Err("Failed to initialise heap: error");
-    }
+    // TODO: Reenable the heap.
+    // if init_heap().is_err() {
+    // return Err("Failed to initialise heap: error");
+    // }
     println_log!("[Success]");
 
+    print_log!("    Enabling PICs... ");
+    interrupts::enable_pic();
+    println_log!("[Success]");
+
+    // print_log!("    Disabling PICs... ");
+    // interrupts::disable_pic();
+    // println_log!("[Success]");
+    //
+    // print_log!("    Initialising APIC");
+    // enable_apic(&mut l4_table, &mut frame_allocator);
+    // println_log!("[Success]");
+
     print_log!("    Enabling Interrupts... ");
     x86_64::instructions::interrupts::enable();
     println_log!("[Success]");

kernel/src/main.rs

@@ -5,8 +5,8 @@ extern crate alloc;
 
 use libk::{
     drivers::{
+        async_io::task::{Executor, Task},
         io,
-        scheduling::task::{Executor, Task},
     },
     prelude::*,
     util::shell::shell,
@@ -28,6 +28,13 @@ extern "C" fn kmain() -> ! {
     println!("Dimensions: {}x{} (chars)", dimensions.0, dimensions.1);
 
     let mut executor = Executor::new();
+
+    let mut v = Vec::with_capacity(1000 * 1000);
+    for i in 0..1000 * 1000 {
+        v.push(i);
+    }
+    println!("v.len(): {}", v.len());
+
     executor.spawn(Task::new(shell()));
     executor.run();
 }

libk/src/drivers/async_io/task.rs

@@ -1,3 +1,8 @@
+//! Allows creation of asynchronous IO bound tasks.
+//!
+//! Written by @zxq5 for the most part with code from
+//! [here](https://github.com/phil-opp/blog_os/).
+//!
 use crate::prelude::*;
 use alloc::collections::BTreeMap;
 use alloc::sync::Arc;

libk/src/drivers/io/ascii/mod.rs

@@ -72,7 +72,7 @@ impl Writer {
         }
 
         // Get the character data from the font array. -- each byte is a row of pixels
-        let data: &[u8] = &self.font.0[c as usize];
+        let data: &[u8] = &self.font.glyphs[c as usize];
 
         if let Some(writer) = FRAMEBUFFER_WRITER.lock().as_mut() {
             for (row, line) in data.iter().enumerate().take(16) {

libk/src/drivers/kalloc/allocator.rs

@@ -1,45 +0,0 @@
-use linked_list_allocator::LockedHeap;
-use x86_64::{
-    VirtAddr,
-    structures::paging::{
-        FrameAllocator, Mapper, Page, PageTableFlags, Size4KiB, mapper::MapToError,
-    },
-};
-
-/// We are currently using a linked list heap allocator which uses our underlying page allocator.
-pub type FoundryAllocator = LockedHeap;
-
-#[global_allocator]
-/// This is now Rust's global allocator, so we can use stuff requiring heap allocations.
-static ALLOCATOR: FoundryAllocator = FoundryAllocator::empty();
-
-pub const HEAP_START: usize = 0x4444_4444_0000;
-pub const HEAP_SIZE: usize = 1000 * 1024;
-
-/// Sets up the heap using the backing page frame allocator.
-pub fn init_heap(
-    mapper: &mut impl Mapper<Size4KiB>,
-    frame_allocator: &mut impl FrameAllocator<Size4KiB>,
-) -> Result<(), MapToError<Size4KiB>> {
-    let range = {
-        let heap_start = VirtAddr::new(HEAP_START as u64);
-        let heap_end = heap_start + HEAP_SIZE as u64 - 1u64;
-        let heap_start_page = Page::<Size4KiB>::containing_address(heap_start);
-        let heap_end_page = Page::<Size4KiB>::containing_address(heap_end);
-        Page::range_inclusive(heap_start_page, heap_end_page)
-    };
-
-    for page in range {
-        let frame = frame_allocator
-            .allocate_frame()
-            .ok_or(MapToError::FrameAllocationFailed)?;
-        let flags = PageTableFlags::PRESENT | PageTableFlags::WRITABLE;
-        unsafe { mapper.map_to(page, frame, flags, frame_allocator)?.flush() };
-    }
-
-    unsafe {
-        ALLOCATOR.lock().init(HEAP_START as *mut u8, HEAP_SIZE);
-    }
-
-    Ok(())
-}

libk/src/drivers/kalloc/mod.rs

@@ -1 +0,0 @@
-pub mod allocator;

libk/src/drivers/mod.rs

@@ -1,3 +1,3 @@
+pub mod async_io;
 pub mod io;
-pub mod kalloc;
-pub mod scheduling;
+pub mod pic;

libk/src/drivers/pic.rs

@@ -0,0 +1,146 @@
+use x86_64::instructions::port::Port;
+
+const CMD_INIT: u8 = 0x11;
+const CMD_END_OF_INT: u8 = 0x20;
+const MODE_8086: u8 = 0x01;
+
+struct Pic {
+    offset: u8,
+    data: Port<u8>,
+    command: Port<u8>,
+}
+
+impl Pic {
+    /// Are we in charge of handling the specified interrupt?
+    /// (Each PIC handles 8 interrupts.)
+    const fn handles_interrupt(&self, interrupt_id: u8) -> bool {
+        self.offset <= interrupt_id && interrupt_id < self.offset + 8
+    }
+
+    /// Notify us that an interrupt has been handled and that we're ready
+    /// for more.
+    unsafe fn end_of_interrupt(&mut self) {
+        unsafe { self.command.write(CMD_END_OF_INT) };
+    }
+
+    /// Reads the interrupt mask of this PIC.
+    unsafe fn read_mask(&mut self) -> u8 {
+        unsafe { self.data.read() }
+    }
+
+    /// Writes the interrupt mask of this PIC.
+    unsafe fn write_mask(&mut self, mask: u8) {
+        unsafe { self.data.write(mask) }
+    }
+}
+
+/// A pair of chained PICs.  This is the standard setup on x86.
+pub struct ChainedPics {
+    pics: [Pic; 2],
+}
+
+impl ChainedPics {
+    pub const fn new(offset1: u8, offset2: u8) -> Self {
+        Self {
+            pics: [
+                Pic {
+                    offset: offset1,
+                    command: Port::new(0x20),
+                    data: Port::new(0x21),
+                },
+                Pic {
+                    offset: offset2,
+                    command: Port::new(0xA0),
+                    data: Port::new(0xA1),
+                },
+            ],
+        }
+    }
+
+    pub const fn new_contiguous(primary_offset: u8) -> Self {
+        Self::new(primary_offset, primary_offset + 8)
+    }
+
+    /// # Safety
+    ///
+    /// This should be safe if called just once on initialisation, however
+    /// sending data to IO ports tends to have side-effects.
+    pub unsafe fn initialize(&mut self) {
+        unsafe {
+            let mut wait_port: Port<u8> = Port::new(0x80);
+            let mut wait = || wait_port.write(0);
+
+            // Save our original interrupt masks, because I'm too lazy to
+            // figure out reasonable values. We'll restore these when we're
+            // done.
+            let saved_masks = self.read_masks();
+
+            // Tell each PIC that we're going to send it a three-byte
+            // initialization sequence on its data port.
+            self.pics[0].command.write(CMD_INIT);
+            wait();
+            self.pics[1].command.write(CMD_INIT);
+            wait();
+
+            // Byte 1: Set up our base offsets.
+            self.pics[0].data.write(self.pics[0].offset);
+            wait();
+            self.pics[1].data.write(self.pics[1].offset);
+            wait();
+
+            // Byte 2: Configure chaining between PIC1 and PIC2.
+            self.pics[0].data.write(4);
+            wait();
+            self.pics[1].data.write(2);
+            wait();
+
+            // Byte 3: Set our mode.
+            self.pics[0].data.write(MODE_8086);
+            wait();
+            self.pics[1].data.write(MODE_8086);
+            wait();
+
+            // Restore our saved masks.
+            self.write_masks(saved_masks[0], saved_masks[1])
+        }
+    }
+
+    /// Reads the interrupt masks of both PICs.
+    pub fn read_masks(&mut self) -> [u8; 2] {
+        unsafe { [self.pics[0].read_mask(), self.pics[1].read_mask()] }
+    }
+
+    /// Writes the interrupt masks of both PICs.
+    pub fn write_masks(&mut self, mask1: u8, mask2: u8) {
+        unsafe {
+            self.pics[0].write_mask(mask1);
+            self.pics[1].write_mask(mask2);
+        }
+    }
+
+    /// Disables both PICs by masking all interrupts.
+    pub fn disable(&mut self) {
+        self.write_masks(u8::MAX, u8::MAX)
+    }
+
+    /// Do we handle this interrupt?
+    pub fn handles_interrupt(&self, interrupt_id: u8) -> bool {
+        self.pics.iter().any(|p| p.handles_interrupt(interrupt_id))
+    }
+
+    /// Figure out which (if any) PICs in our chain need to know about this
+    /// interrupt.  This is tricky, because all interrupts from `pics[1]`
+    /// get chained through `pics[0]`.
+    pub fn notify_end_of_interrupt(&mut self, interrupt_id: u8) {
+        if self.handles_interrupt(interrupt_id) {
+            if self.pics[1].handles_interrupt(interrupt_id) {
+                unsafe {
+                    self.pics[1].end_of_interrupt();
+                }
+            }
+            unsafe {
+                self.pics[0].end_of_interrupt();
+            }
+        }
+    }
+}

libk/src/lib.rs

@@ -1,6 +1,4 @@
 #![no_std]
-#![allow(async_fn_in_trait)]
-#![warn(tail_expr_drop_order)]
 #![warn(
     clippy::correctness,
     clippy::nursery,
@@ -9,18 +7,15 @@
     clippy::suspicious,
     clippy::perf,
     rustdoc::missing_errors_doc,
-    rustdoc::missing_panics_doc
+    rustdoc::missing_panics_doc,
+    tail_expr_drop_order
 )]
 
-// alloc
-// io : serial, framebuffer, ascii(?), keyboard
-// ?????
-// scheduling / tasks : async
-
 extern crate alloc;
 
 pub mod drivers;
 pub mod resources;
+pub mod threads;
 pub mod util;
 
 #[allow(unused)] // We aren't using much of this right now.
@@ -41,3 +36,12 @@ pub use crate::drivers::io::{
     ascii::{_print, _print_log},
     serial::_serial_write,
 };
+
+pub type FoundryAllocator = linked_list_allocator::LockedHeap;
+
+#[global_allocator]
+/// This is now Rust's global allocator, so we can use stuff requiring heap allocations.
+static ALLOCATOR: FoundryAllocator = FoundryAllocator::empty();
+
+pub const HEAP_START: usize = 0x4444_4444_0000;
+pub const HEAP_SIZE: usize = 1024 * 1024 * 1024;

libk/src/resources/font/mod.rs

@@ -1,13 +1,26 @@
+// use libm::include_font;
+
 use libm::include_font;
 
 pub mod ibm_vga_8x16;
 
-pub static FONT_SPLEEN_8X16: Font = Font(include_font!(
-    "./libk/resources/font/spleen-8x16.psf"
-));
+pub static FONT_SPLEEN_8X16: Font =
+    Font::new(include_font!("./libk/resources/font/spleen-8x16.psf"));
 
-pub static FONT_CP850_8X16: Font = Font(include_font!(
-    "./libk/resources/font/cp850-8x16.psf"
-));
+pub static FONT_CP850_8X16: Font = Font::new(include_font!("./libk/resources/font/cp850-8x16.psf"));
 
-pub struct Font(pub [[u8; 16]; 512]);
+pub struct Font {
+    pub glyphs: [[u8; 16]; 512],
+}
+
+impl Default for Font {
+    fn default() -> Self {
+        Self::new([[0; 16]; 512])
+    }
+}
+
+impl Font {
+    pub const fn new(glyphs: [[u8; 16]; 512]) -> Self {
+        Self { glyphs }
+    }
+}

libk/src/std/application.rs

@@ -7,7 +7,10 @@ mod window;
 pub trait Application {
     type Output;
 
-    async fn run(&mut self, args: Vec<String>) -> Result<Self::Output, Error>;
+    fn run(
+        &mut self,
+        args: Vec<String>,
+    ) -> impl core::future::Future<Output = Result<Self::Output, Error>> + Send;
 }
 
 #[derive(Debug)]

libk/src/std/io/mod.rs

@@ -1,2 +0,0 @@
-mod io;
-pub use io::*;

libk/src/threads.rs

@@ -0,0 +1,113 @@
+use core::arch::asm;
+
+#[repr(C)]
+pub struct Thread {
+    id: usize,
+    /// This shall be default before the program is interrupted, otherwise it will store
+    /// CPU registers etc to be restored on context switch.
+    ctx: ThreadContext,
+}
+
+/// CPU state to be saved on context switches.
+#[repr(C)]
+#[derive(Default)]
+pub struct ThreadContext {
+    /// Accumulator register.
+    rax: u64,
+    /// Base register.
+    rbx: u64,
+    /// Counter register.
+    rcx: u64,
+    /// Data register.
+    rdx: u64,
+    /// Source index register.
+    rsi: u64,
+    /// Destination index register.
+    rdi: u64,
+    /// Base pointer register.
+    rbp: u64,
+    /// Stack pointer register.
+    rsp: u64,
+    /// An extended register.
+    r8: u64,
+    /// An extended register.
+    r9: u64,
+    /// An extended register.
+    r10: u64,
+    /// An extended register.
+    r11: u64,
+    /// An extended register.
+    r12: u64,
+    /// An extended register.
+    r13: u64,
+    /// An extended register.
+    r14: u64,
+    /// An extended register.
+    r15: u64,
+    /// The instruction pointer.
+    rip: u64,
+    /// RFLAGS register.
+    rflags: u64,
+}
+
+impl ThreadContext {
+    /// Saves the current registers of the CPU before a context switch
+    /// to be restored later.
+    ///
+    /// # Notes
+    ///
+    /// This function should ONLY be called in interrupt handlers such
+    /// as that of the timer. This will then save registers as required
+    ///
+    ///
+    /// # Safety
+    ///
+    /// This function is unsafe because of the usage of inline ASM.
+    #[inline(always)]
+    pub unsafe fn save_registers() -> Self {
+        let mut context = Self::default();
+        unsafe {
+            asm!(
+                "mov {0}, rax",
+                "mov {1}, rbx",
+                "mov {2}, rcx",
+                "mov {3}, rdx",
+                "mov {4}, rsi",
+                "mov {5}, rdi",
+                "mov {6}, rbp",
+                "mov {7}, rsp",
+                "mov {8}, r8",
+                "mov {9}, r9",
+                "mov {10}, r10",
+                "mov {11}, r11",
+                "mov {12}, r12",
+                "mov {13}, r13",
+                "mov {14}, r14",
+                "mov {15}, r15",
+                "lea {16}, [rip]",
+                "pushf",
+                "pop {17}",
+                out(reg) context.rax,
+                out(reg) context.rbx,
+                out(reg) context.rcx,
+                out(reg) context.rdx,
+                out(reg) context.rsi,
+                out(reg) context.rdi,
+                out(reg) context.rbp,
+                out(reg) context.rsp,
+                out(reg) context.r8,
+                out(reg) context.r9,
+                out(reg) context.r10,
+                out(reg) context.r11,
+                out(reg) context.r12,
+                out(reg) context.r13,
+                out(reg) context.r14,
+                out(reg) context.r15,
+                out(reg) context.rip,
+                out(reg) context.rflags,
+            );
+        }
+
+        context
+    }
+}

libk/src/util/shell.rs

@@ -1,4 +1,4 @@
-use x86_64::registers::rflags::read;
+// use x86_64::registers::rflags::read;
 
 use crate::{drivers::io::ascii::clear_screen, prelude::stdin::read_line, print, println};
 

scripts/build.sh

@@ -0,0 +1,109 @@
+#!/bin/bash
+
+# Colors
+GREEN='\033[0;32m'
+BLUE='\033[0;34m'
+YELLOW='\033[0;33m'
+RED='\033[0;31m'
+BOLD='\033[1m'
+NC='\033[0m' # No Color
+
+# Error handling
+set -e
+trap 'echo -e "${RED}${BOLD}error${NC}: build failed" >&2' ERR
+
+# Get absolute path to project root
+project_root=$(cd "$script_dir/.." &>/dev/null && pwd)
+build_dir="$project_root/build"
+iso_root="$build_dir/iso_root"
+
+# Logging functions
+info() {
+    echo -e "${BLUE}${BOLD}info${NC}: $1"
+}
+
+compiling() {
+    echo -e "${GREEN}${BOLD}Compiling${NC}: $1"
+}
+
+warning() {
+    echo -e "${YELLOW}${BOLD}warning${NC}: $1" >&2
+}
+
+building() {
+    echo -e "${GREEN}${BOLD}Building${NC}: $1"
+}
+
+copying() {
+    echo -e "${GREEN}${BOLD}  Copying${NC}: $1 to $2"
+}
+
+error() {
+    echo -e "${RED}${BOLD}error${NC}: $1" >&2
+    exit 1
+}
+
+copy_file() {
+    copying $1 $2
+    cp "$1" "$2" || error $3
+}
+
+# Check if we're running tests
+if [[ $1 == *"deps"* ]]; then
+    kernel_path="$1"
+else
+    # Build the kernel normally
+    cd "$project_root"
+    # cargo build
+    kernel_path="$build_dir/target/x86_64-kernel/debug/kernel"
+fi
+
+# Check for required tools
+check_tools() {
+    local missing=0
+    for tool in xorriso git qemu-system-x86_64; do
+        if ! command -v $tool >/dev/null 2>&1; then
+            error "required tool '$tool' is not installed"
+            missing=1
+        fi
+    done
+    if [ $missing -eq 1 ]; then
+        error "missing required tools"
+    fi
+}
+
+# Create build directory structure
+info "Creating build directory structure"
+mkdir -p "$iso_root/boot/limine"
+mkdir -p "$iso_root/EFI/BOOT"
+
+# Clone Limine if needed
+if [ ! -d "$build_dir/limine" ]; then
+    compiling "limine bootloader"
+    cd "$build_dir"
+    git clone https://github.com/limine-bootloader/limine.git --branch=v9.x-binary --depth=1 "$build_dir/limine" || error "failed to clone limine"
+    make -C "$build_dir/limine" || error "failed to build limine"
+    cd "$project_root"
+fi
+
+# Copy files
+info "Copying files to ISO root"
+copy_file "$kernel_path" "$iso_root/boot/kernel" "failed to copy kernel"
+copy_file "$project_root/config/limine.conf" "$iso_root/boot/limine/limine.conf" "failed to copy limine config"
+copy_file "$build_dir/limine/limine-bios-cd.bin" "$iso_root/boot/limine/" "failed to copy limine-bios-cd.bin"
+copy_file "$build_dir/limine/limine-uefi-cd.bin" "$iso_root/boot/limine/" "failed to copy limine-uefi-cd.bin"
+copy_file "$build_dir/limine/limine-bios.sys" "$iso_root/boot/limine/" "failed to copy limine-bios.sys"
+copy_file "$build_dir/limine/BOOTX64.EFI" "$iso_root/EFI/BOOT/" "failed to copy BOOTX64.EFI"
+copy_file "$build_dir/limine/BOOTIA32.EFI" "$iso_root/EFI/BOOT/" "failed to copy BOOTIA32.EFI"
+
+# Create ISO
+building "bootable ISO image"
+xorriso -as mkisofs -R -r -J -b boot/limine/limine-bios-cd.bin \
+        -no-emul-boot -boot-load-size 4 -boot-info-table -hfsplus \
+        -apm-block-size 2048 --efi-boot boot/limine/limine-uefi-cd.bin \
+        -efi-boot-part --efi-boot-image --protective-msdos-label \
+        "$iso_root" -o "$build_dir/image.iso" || error "failed to create ISO"
+
+# Install Limine
+info "Installing Limine bootloader"
+"$build_dir/limine/limine" bios-install "$build_dir/image.iso" || error "failed to install limine"

scripts/flash_iso.sh

@@ -0,0 +1,20 @@
+#!/bin/bash
+
+script_dir=$(cd -- "$(dirname -- "${BASH_SOURCE[0]}")" &>/dev/null && pwd)
+
+source scripts/build.sh
+
+warning "This script will OVERWRITE whatever media you throw at it\nwith the built ISO."
+
+info "sudo ./hardware.sh /dev/yourdisk"
+
+if ! echo "$1" | grep -q "/dev"; then
+    error "invalid device"
+fi
+
+read -p "Confirm (y/n): " confirmation
+if [ "$confirmation" != "y" ]; then
+    exit 0
+fi
+
+dd if=./build/image.iso of="$1"

scripts/hardware.sh

@@ -1,2 +0,0 @@
-#!/bin/bash
-sudo dd if=./build/image.iso of="$1"

scripts/run_debug.sh

@@ -2,120 +2,16 @@
 
 # Script originally written by zxq5, I added separate scripts to remove `jq` dependency.
 
-# Colors
-GREEN='\033[0;32m'
-BLUE='\033[0;34m'
-YELLOW='\033[0;33m'
-RED='\033[0;31m'
-BOLD='\033[1m'
-NC='\033[0m' # No Color
+script_dir=$(cd -- "$(dirname -- "${BASH_SOURCE[0]}")" &>/dev/null && pwd)
+
+source $script_dir/build.sh
 
 # Error handling
 set -e
 trap 'echo -e "${RED}${BOLD}error${NC}: build failed" >&2' ERR
 
-# Get absolute path to project root
-script_dir=$(cd -- "$(dirname -- "${BASH_SOURCE[0]}")" &>/dev/null && pwd)
-project_root=$(cd "$script_dir/.." &>/dev/null && pwd)
-
 echo -e "${GREEN}${BOLD} Running kernel in debug mode."
 
-# Logging functions
-info() {
-    echo -e "${BLUE}${BOLD}info${NC}: $1"
-}
-
-compiling() {
-    echo -e "${GREEN}${BOLD}Compiling${NC}: $1"
-}
-
-warning() {
-    echo -e "${YELLOW}${BOLD}warning${NC}: $1" >&2
-}
-
-building() {
-    echo -e "${GREEN}${BOLD}Building${NC}: $1"
-}
-
-copying() {
-    echo -e "${GREEN}${BOLD}  Copying${NC}: $1 to $2"
-}
-
-error() {
-    echo -e "${RED}${BOLD}error${NC}: $1" >&2
-    exit 1
-}
-
-copy_file() {
-    copying $1 $2
-    cp "$1" "$2" || error $3
-}
-
-build_dir="$project_root/build"
-iso_root="$build_dir/iso_root"
-
-# Check if we're running tests
-is_test=0
-if [[ $1 == *"deps"* ]]; then
-    is_test=1
-    kernel_path="$1"
-else
-    # Build the kernel normally
-    cd "$project_root"
-    # cargo build
-    kernel_path="$build_dir/target/x86_64-kernel/debug/kernel"
-fi
-
-# Check for required tools
-check_tools() {
-    local missing=0
-    for tool in xorriso git qemu-system-x86_64; do
-        if ! command -v $tool >/dev/null 2>&1; then
-            error "required tool '$tool' is not installed"
-            missing=1
-        fi
-    done
-    if [ $missing -eq 1 ]; then
-        error "missing required tools"
-    fi
-}
-
-# Create build directory structure
-info "Creating build directory structure"
-mkdir -p "$iso_root/boot/limine"
-mkdir -p "$iso_root/EFI/BOOT"
-
-# Clone Limine if needed
-if [ ! -d "$build_dir/limine" ]; then
-    compiling "limine bootloader"
-    cd "$build_dir"
-    git clone https://github.com/limine-bootloader/limine.git --branch=v9.x-binary --depth=1 "$build_dir/limine" || error "failed to clone limine"
-    make -C "$build_dir/limine" || error "failed to build limine"
-    cd "$project_root"
-fi
-
-# Copy files
-info "Copying files to ISO root"
-copy_file "$kernel_path" "$iso_root/boot/kernel" "failed to copy kernel"
-copy_file "$project_root/config/limine.conf" "$iso_root/boot/limine/limine.conf" "failed to copy limine config"
-copy_file "$build_dir/limine/limine-bios-cd.bin" "$iso_root/boot/limine/" "failed to copy limine-bios-cd.bin"
-copy_file "$build_dir/limine/limine-uefi-cd.bin" "$iso_root/boot/limine/" "failed to copy limine-uefi-cd.bin"
-copy_file "$build_dir/limine/limine-bios.sys" "$iso_root/boot/limine/" "failed to copy limine-bios.sys"
-copy_file "$build_dir/limine/BOOTX64.EFI" "$iso_root/EFI/BOOT/" "failed to copy BOOTX64.EFI"
-copy_file "$build_dir/limine/BOOTIA32.EFI" "$iso_root/EFI/BOOT/" "failed to copy BOOTIA32.EFI"
-
-# Create ISO
-building "bootable ISO image"
-xorriso -as mkisofs -R -r -J -b boot/limine/limine-bios-cd.bin \
-        -no-emul-boot -boot-load-size 4 -boot-info-table -hfsplus \
-        -apm-block-size 2048 --efi-boot boot/limine/limine-uefi-cd.bin \
-        -efi-boot-part --efi-boot-image --protective-msdos-label \
-        "$iso_root" -o "$build_dir/image.iso" || error "failed to create ISO"
-
-# Install Limine
-info "Installing Limine bootloader"
-"$build_dir/limine/limine" bios-install "$build_dir/image.iso" || error "failed to install limine"
-
 # Check if KVM is available
 if [ "${KVM_FLAG:-enable}" = "disable" ]; then
     warning "KVM acceleration disabled by user"
@@ -145,6 +41,31 @@ else
     serial_flags="-serial stdio"
 fi
 
+# Set up VM memory
+if [ $VM_MEMORY ]; then
+    vm_memory_flag="-m $VM_MEMORY"
+else
+    vm_memory_flag="-m 2G"
+fi
+
+# Set up boot flags
+if [ $USE_LEGACY_BIOS ]; then
+    boot_flags=""
+else
+#   Check for the presence of the OVMF firmware.
+    if [ ! -f $build_dir/RELEASEX64_OVMF_CODE.fd ]; then
+        info "Downloading OVMF UEFI firmware for QEMU"
+        info "To disable this, set USE_LEGACY_BIOS=1."
+        pushd $build_dir
+        curl https://retrage.github.io/edk2-nightly/bin/RELEASEX64_OVMF_CODE.fd -LO || error "failed to download OVMF firmware for UEFI"
+        curl https://retrage.github.io/edk2-nightly/bin/RELEASEX64_OVMF_VARS.fd -LO || error "failed to download OVMF firmware for UEFI"
+        popd
+    fi
+
+    boot_flags="-drive if=pflash,format=raw,readonly=on,file=$build_dir/RELEASEX64_OVMF_CODE.fd \
+                -drive if=pflash,format=raw,file=$build_dir/RELEASEX64_OVMF_VARS.fd"
+fi
+
 # Run in QEMU
 if [[ ${QEMU_FLAGS} == *-S* ]]; then
     info "Running OS in QEMU with GDB debugging enabled"
@@ -171,23 +92,18 @@ check_test_res() {
     fi
 }
 
-
-kvm_flag=""
-
 trap 'check_test_res "tests completed"' ERR
  
-    # $build_dir/image.iso
-
-
 cd "$project_root"
 qemu-system-x86_64 -M q35 \
     -cdrom "$build_dir/image.iso" \
     ${kvm_flag} \
     -boot d \
-    -m 2G \
+    ${vm_memory_flag} \
     ${serial_flags} \
     -no-reboot \
     ${test_flags} \
     ${debug_flags} \
+    ${boot_flags} \
     ${QEMU_FLAGS:-}
 

scripts/run_release.sh

@@ -2,120 +2,23 @@
 
 # Script originally written by zxq5, I added separate scripts to remove `jq` dependency.
 
-# Colors
-GREEN='\033[0;32m'
-BLUE='\033[0;34m'
-YELLOW='\033[0;33m'
-RED='\033[0;31m'
-BOLD='\033[1m'
-NC='\033[0m' # No Color
+script_dir=$(cd -- "$(dirname -- "${BASH_SOURCE[0]}")" &>/dev/null && pwd)
+
+source $script_dir/build.sh
 
 # Error handling
 set -e
 trap 'echo -e "${RED}${BOLD}error${NC}: build failed" >&2' ERR
 
-# Get absolute path to project root
-script_dir=$(cd -- "$(dirname -- "${BASH_SOURCE[0]}")" &>/dev/null && pwd)
-project_root=$(cd "$script_dir/.." &>/dev/null && pwd)
-
 echo -e "${GREEN}${BOLD} Running kernel in release mode."
 
-# Logging functions
-info() {
-    echo -e "${BLUE}${BOLD}info${NC}: $1"
-}
 
-compiling() {
-    echo -e "${GREEN}${BOLD}Compiling${NC}: $1"
-}
-
-warning() {
-    echo -e "${YELLOW}${BOLD}warning${NC}: $1" >&2
-}
-
-building() {
-    echo -e "${GREEN}${BOLD}Building${NC}: $1"
-}
-
-copying() {
-    echo -e "${GREEN}${BOLD}  Copying${NC}: $1 to $2"
-}
-
-error() {
-    echo -e "${RED}${BOLD}error${NC}: $1" >&2
-    exit 1
-}
-
-copy_file() {
-    copying $1 $2
-    cp "$1" "$2" || error $3
-}
-
-build_dir="$project_root/build"
-iso_root="$build_dir/iso_root"
-
-# Check if we're running tests
-is_test=0
-if [[ $1 == *"deps"* ]]; then
-    is_test=1
-    kernel_path="$1"
+if [ $VM_MEMORY ]; then
+    vm_memory_flag="-m $VM_MEMORY"
 else
-    # Build the kernel normally
-    cd "$project_root"
-    # cargo build
-    kernel_path="$build_dir/target/x86_64-kernel/release/kernel"
+    vm_memory_flag="-m 2G"
 fi
 
-# Check for required tools
-check_tools() {
-    local missing=0
-    for tool in xorriso git qemu-system-x86_64; do
-        if ! command -v $tool >/dev/null 2>&1; then
-            error "required tool '$tool' is not installed"
-            missing=1
-        fi
-    done
-    if [ $missing -eq 1 ]; then
-        error "missing required tools"
-    fi
-}
-
-# Create build directory structure
-info "Creating build directory structure"
-mkdir -p "$iso_root/boot/limine"
-mkdir -p "$iso_root/EFI/BOOT"
-
-# Clone Limine if needed
-if [ ! -d "$build_dir/limine" ]; then
-    compiling "limine bootloader"
-    cd "$build_dir"
-    git clone https://github.com/limine-bootloader/limine.git --branch=v9.x-binary --depth=1 "$build_dir/limine" || error "failed to clone limine"
-    make -C "$build_dir/limine" || error "failed to build limine"
-    cd "$project_root"
-fi
-
-# Copy files
-info "Copying files to ISO root"
-copy_file "$kernel_path" "$iso_root/boot/kernel" "failed to copy kernel"
-copy_file "$project_root/config/limine.conf" "$iso_root/boot/limine/limine.conf" "failed to copy limine config"
-copy_file "$build_dir/limine/limine-bios-cd.bin" "$iso_root/boot/limine/" "failed to copy limine-bios-cd.bin"
-copy_file "$build_dir/limine/limine-uefi-cd.bin" "$iso_root/boot/limine/" "failed to copy limine-uefi-cd.bin"
-copy_file "$build_dir/limine/limine-bios.sys" "$iso_root/boot/limine/" "failed to copy limine-bios.sys"
-copy_file "$build_dir/limine/BOOTX64.EFI" "$iso_root/EFI/BOOT/" "failed to copy BOOTX64.EFI"
-copy_file "$build_dir/limine/BOOTIA32.EFI" "$iso_root/EFI/BOOT/" "failed to copy BOOTIA32.EFI"
-
-# Create ISO
-building "bootable ISO image"
-xorriso -as mkisofs -R -r -J -b boot/limine/limine-bios-cd.bin \
-        -no-emul-boot -boot-load-size 4 -boot-info-table -hfsplus \
-        -apm-block-size 2048 --efi-boot boot/limine/limine-uefi-cd.bin \
-        -efi-boot-part --efi-boot-image --protective-msdos-label \
-        "$iso_root" -o "$build_dir/image.iso" || error "failed to create ISO"
-
-# Install Limine
-info "Installing Limine bootloader"
-"$build_dir/limine/limine" bios-install "$build_dir/image.iso" || error "failed to install limine"
-
 # Check if KVM is available
 if [ "${KVM_FLAG:-enable}" = "disable" ]; then
     warning "KVM acceleration disabled by user"
@@ -128,59 +31,30 @@ else
     kvm_flag=""
 fi
 
-# I'm lazy but I just remove GDB flags when running this script.
-debug_flags=""
-
-# Set up test-specific flags
-if [ $is_test -eq 1 ]; then
-    test_flags="-device isa-debug-exit,iobase=0xf4,iosize=0x04 -display none"
-    serial_flags="-serial stdio"
+if [ $USE_LEGACY_BIOS ]; then
+    boot_flags=""
 else
-    test_flags=""
-    # serial_flags="-serial tcp:127.0.0.1:1234,server -monitor telnet:127.0.0.1:1235,server"
-    serial_flags="-serial stdio"
-fi
-
-# Run in QEMU
-if [[ ${QEMU_FLAGS} == *-S* ]]; then
-    info "Running OS in QEMU with GDB debugging enabled"
-    info "To connect GDB, run: gdb"
-    info "At the GDB prompt, type: target remote localhost:1234"
-else
-    info "Running OS in QEMU..."
-fi
-
-check_test_res() {
-    qemu_exit_code=$?
-    if [ $qemu_exit_code -eq 33 ]; then
-        # Success case (0x10 << 1) | 1 = 33
-        info "All tests passed"
-        exit 0
-    elif [ $qemu_exit_code -eq 35 ]; then
-        # Failure case (0x11 << 1) | 1 = 35
-        warning "Some tests failed"
-        exit 1
-    else
-        # Any other exit code is treated as a failure
-        warning "Some tests failed"
-        exit 1
+#   Check for the presence of the OVMF firmware.
+    if [ ! -f $build_dir/RELEASEX64_OVMF_CODE.fd ]; then
+        info "Downloading OVMF UEFI firmware for QEMU"
+        info "To disable this, set USE_LEGACY_BIOS=1."
+        pushd $build_dir
+        curl https://retrage.github.io/edk2-nightly/bin/RELEASEX64_OVMF_CODE.fd -LO || error "failed to download OVMF firmware for UEFI"
+        curl https://retrage.github.io/edk2-nightly/bin/RELEASEX64_OVMF_VARS.fd -LO || error "failed to download OVMF firmware for UEFI"
+        popd
     fi
-}
 
-
-kvm_flag=""
-
-trap 'check_test_res "tests completed"' ERR
+    boot_flags="-drive if=pflash,format=raw,readonly=on,file=$build_dir/RELEASEX64_OVMF_CODE.fd \
+                -drive if=pflash,format=raw,file=$build_dir/RELEASEX64_OVMF_VARS.fd"
+fi
 
 cd "$project_root"
 qemu-system-x86_64 -M q35 \
     ${kvm_flag} \
     -cdrom "$build_dir/image.iso" \
     -boot d \
-    -m 2G \
+    ${vm_memory_flag} \
     ${serial_flags} \
     -no-reboot \
-    ${test_flags} \
-    ${debug_flags} \
-    ${QEMU_FLAGS:-}
+    ${boot_flags}