kernel: move limine to lib

kernel/Cargo.toml

@@ -20,6 +20,7 @@ harness = false
 [[test]]
 name = "stack_overflow"
 harness = false
+test = false # currently doesn't work reliably because the stack corrupts something
 
 [dependencies]
 bit_field = "0.10.3"

kernel/src/boot.rs

@@ -100,12 +100,19 @@ const impl Default for MemoryRegion {
 pub struct BootInfo {
     pub hhdm_base: u64,
     pub memory_map: &'static [MemoryRegion],
+    pub executable_file: Option<&'static [u8]>,
 }
 
 pub static BOOT_INFO: OnceLock<BootInfo> = OnceLock::new();
 static mut MEMORY_MAP: [MemoryRegion; 128] = [MemoryRegion::default(); 128];
 
-pub fn init_boot_info<I: Iterator<Item = MemoryRegion>>(hhdm_base: u64, memory_map: I) {
+pub fn init_boot_info<I: Iterator<Item = MemoryRegion>>(
+    hhdm_base: u64,
+    memory_map: I,
+    executable_file: Option<&'static [u8]>,
+) {
+    _ = crate::memory::HHDM_BASE.try_insert(hhdm_base);
+
     BOOT_INFO.initialize(|| {
         for (i, region) in memory_map.enumerate() {
             assert!(i < 128, "Memory map has more than 128 entries");
@@ -117,6 +124,7 @@ pub fn init_boot_info<I: Iterator<Item = MemoryRegion>>(hhdm_base: u64, memory_m
         Ok::<_, !>(BootInfo {
             hhdm_base,
             memory_map: unsafe { (&raw const MEMORY_MAP).as_ref_unchecked() },
+            executable_file,
         })
     });
 }

kernel/src/limine.rs

@@ -1,4 +1,6 @@
-use core::{cell::UnsafeCell, ffi::CStr, fmt::Debug, ptr::NonNull};
+use core::{cell::UnsafeCell, fmt::Debug, ptr::NonNull};
+
+use crate::serial_println;
 
 #[repr(C)]
 pub struct BaseRevision(UnsafeCell<[u64; 3]>);
@@ -326,6 +328,46 @@ impl LimineFile {
     }
 }
 
+#[used]
+#[unsafe(link_section = ".limine_requests_start")]
+static LIMINE_REQUESTS_START: RequestsStartMarker = REQUESTS_START_MARKER;
+
 #[used]
 #[unsafe(link_section = ".limine_requests")]
 pub static EXECUTABLE_FILE_REQUEST: ExecutableFileRequest = ExecutableFileRequest::new();
+
+#[used]
+#[unsafe(link_section = ".limine_requests")]
+pub static LIMINE_BASE_REVISION: BaseRevision = BaseRevision::from_revision(6);
+
+#[used]
+#[unsafe(link_section = ".limine_requests")]
+pub static FRAMEBUFFER_REQUEST: FramebufferRequest = FramebufferRequest::new();
+
+#[used]
+#[unsafe(link_section = ".limine_requests")]
+pub static HHDM_REQUEST: HhdmRequest = HhdmRequest::new();
+
+#[used]
+#[unsafe(link_section = ".limine_requests")]
+pub static MEMMAP_REQUEST: MemMapRequest = MemMapRequest::new();
+
+#[used]
+#[unsafe(link_section = ".limine_requests_end")]
+static LIMINE_REQUESTS_END: RequestsEndMarker = REQUESTS_END_MARKER;
+
+pub fn init_limine_boot_info() {
+    crate::boot::init_boot_info(
+        HHDM_REQUEST
+            .offset()
+            .expect("HHDM offset not provided by bootloader"),
+        MEMMAP_REQUEST
+            .entries()
+            .iter()
+            .inspect(|e| {
+                serial_println!("{e:?}");
+            })
+            .map(|&&e| e.into()),
+        EXECUTABLE_FILE_REQUEST.file().map(|f| f.bytes()),
+    );
+}

kernel/src/main.rs

@@ -23,25 +23,9 @@ static GDT: LazyLock<GlobalDescriptorTable> = LazyLock::new(GlobalDescriptorTabl
 #[unsafe(no_mangle)]
 extern "C" fn _start() -> ! {
     kernel::logger::init(log::LevelFilter::Trace);
-    assert!(limine_requests::LIMINE_BASE_REVISION.is_supported());
+    assert!(kernel::limine::LIMINE_BASE_REVISION.is_supported());
 
-    _ = kernel::memory::HHDM_BASE
+    kernel::limine::init_limine_boot_info();
-        .try_insert(
-            limine_requests::HHDM_REQUEST
-                .offset()
-                .expect("HHDM offset not provided by bootloader"),
-        )
-        .expect("HHDM offset already set");
-
-    kernel::boot::init_boot_info(
-        limine_requests::HHDM_REQUEST
-            .offset()
-            .expect("HHDM offset not provided by bootloader"),
-        limine_requests::MEMMAP_REQUEST
-            .entries()
-            .iter()
-            .map(|&&e| e.into()),
-    );
 
     kernel::serial_println!(
         "HHDM offset: 0x{:#x}",
@@ -50,13 +34,12 @@ extern "C" fn _start() -> ! {
 
     kernel::serial_println!(
         "Memory map: {:#?}",
-        limine_requests::MEMMAP_REQUEST.entries()
+        kernel::limine::MEMMAP_REQUEST.entries()
     );
 
     GDT.load();
     IDT.load();
 
-
     kernel::serial_println!("entry point: 0x{:x}", _start as *const () as usize);
     kernel::serial_println!(
         "entry point phy: {:?}",
@@ -75,7 +58,7 @@ extern "C" fn _start() -> ! {
 
     kernel::serial_println!("PMM: {pmm:#?}");
 
-    let fb = limine_requests::FRAMEBUFFER_REQUEST
+    let fb = kernel::limine::FRAMEBUFFER_REQUEST
         .framebuffers()
         .first()
         .expect("No framebuffer found");
@@ -95,34 +78,3 @@ extern "C" fn _start() -> ! {
 
     kernel::x86_64::halt_loop()
 }
-
-mod limine_requests {
-    use kernel::limine::{
-        BaseRevision, FramebufferRequest, REQUESTS_END_MARKER, REQUESTS_START_MARKER,
-        RequestsEndMarker, RequestsStartMarker,
-    };
-
-    #[used]
-    #[unsafe(link_section = ".limine_requests_start")]
-    static LIMINE_REQUESTS_START: RequestsStartMarker = REQUESTS_START_MARKER;
-
-    #[used]
-    #[unsafe(link_section = ".limine_requests")]
-    pub static LIMINE_BASE_REVISION: BaseRevision = BaseRevision::from_revision(6);
-
-    #[used]
-    #[unsafe(link_section = ".limine_requests")]
-    pub static FRAMEBUFFER_REQUEST: FramebufferRequest = FramebufferRequest::new();
-
-    #[used]
-    #[unsafe(link_section = ".limine_requests")]
-    pub static HHDM_REQUEST: kernel::limine::HhdmRequest = kernel::limine::HhdmRequest::new();
-
-    #[used]
-    #[unsafe(link_section = ".limine_requests")]
-    pub static MEMMAP_REQUEST: kernel::limine::MemMapRequest = kernel::limine::MemMapRequest::new();
-
-    #[used]
-    #[unsafe(link_section = ".limine_requests_end")]
-    static LIMINE_REQUESTS_END: RequestsEndMarker = REQUESTS_END_MARKER;
-}

kernel/src/x86_64/backtrace.rs

@@ -1,4 +1,4 @@
-use core::ffi::{CStr, c_void};
+use core::ffi::c_void;
 
 use crate::{
     limine::LimineFile,

kernel/src/x86_64/gdt.rs

@@ -472,7 +472,6 @@ const PRIVILEGE_STACK_TABLE_SIZE: usize = 3;
 const INTERRUPT_STACK_TABLE_SIZE: usize = 7;
 
 #[repr(C, packed(4))]
-#[derive(Debug)]
 pub struct TaskStateSegment {
     _reserved1: [u8; 4],
     pub privilege_stack_table: [u64; PRIVILEGE_STACK_TABLE_SIZE],
@@ -482,6 +481,31 @@ pub struct TaskStateSegment {
     pub iomap_base: u16,
 }
 
+impl Debug for TaskStateSegment {
+    fn fmt(&self, f: &mut core::fmt::Formatter<'_>) -> core::fmt::Result {
+        let mut dbg = f.debug_struct("TaskStateSegment");
+
+        let rsps = self.privilege_stack_table;
+        let ists = self.interrupt_stack_table;
+
+        dbg.field("RSP0", &format_args!("{:#x}", rsps[0]))
+            .field("RSP1", &format_args!("{:#x}", rsps[1]))
+            .field("RSP2", &format_args!("{:#x}", rsps[2]));
+
+        dbg.field("IST1", &format_args!("{:#x}", ists[0]))
+            .field("IST2", &format_args!("{:#x}", ists[1]))
+            .field("IST3", &format_args!("{:#x}", ists[2]))
+            .field("IST4", &format_args!("{:#x}", ists[3]))
+            .field("IST5", &format_args!("{:#x}", ists[4]))
+            .field("IST6", &format_args!("{:#x}", ists[5]))
+            .field("IST7", &format_args!("{:#x}", ists[6]));
+
+        dbg.field("iomap_base", &format_args!("{:#x}", self.iomap_base));
+
+        dbg.finish()
+    }
+}
+
 impl TaskStateSegment {
     pub const fn new() -> Self {
         Self {
@@ -514,7 +538,7 @@ pub const MC_STACK: u8 = 2;
 pub const PF_STACK: u8 = 3;
 
 const STACK_SIZE: usize = super::PAGE_SIZE * 5;
-#[repr(align(16))]
+#[repr(align(4096))]
 pub struct Stack(MaybeUninit<[u8; STACK_SIZE]>);
 
 impl Stack {

kernel/src/x86_64/idt.rs

@@ -523,7 +523,12 @@ extern "C" fn global_interrupt_handler(
             serial_println!("Breakpoint interrupt handled successfully.");
         }
         ExceptionVector::PAGE_FAULT => {
-            serial_println!("Page fault occurred! Error code: {:#x}", error_code);
+            let cr2 = super::registers::Cr2::read();
+            serial_println!(
+                "Page fault occurred! Error code: {:#x} CR2: {:#x}",
+                error_code,
+                cr2.0
+            );
             debug_backtrace(&Context {
                 rip: frame.instruction_pointer,
                 registers: *registers,

kernel/src/x86_64/registers.rs

@@ -64,6 +64,17 @@ bitflags::bitflags! {
     }
 }
 
+pub struct Cr2(pub u64);
+impl Cr2 {
+    pub fn read() -> Self {
+        let value: u64;
+        unsafe {
+            asm!("mov {}, cr2", out(reg) value, options(nomem, nostack, preserves_flags));
+        }
+        Self(value)
+    }
+}
+
 impl Cr4 {
     pub fn read() -> Self {
         let value: u64;

kernel/tests/stack_overflow.rs

@@ -5,6 +5,7 @@
 use core::{cell::UnsafeCell, mem::offset_of};
 
 use kernel::{
+    serial_println,
     sync::LazyLock,
     x86_64::{
         gdt::{DF_STACK, GlobalDescriptorTable, RING0},
@@ -17,6 +18,7 @@ pub static GDT: LazyLock<GlobalDescriptorTable> = LazyLock::new(GlobalDescriptor
 #[unsafe(export_name = "_start")]
 pub extern "C" fn main() -> ! {
     kernel::serial_println!("Hello, world!");
+    kernel::limine::init_limine_boot_info();
 
     GDT.load();
     kernel::serial_println!("[ok] GDT loaded");