mirror of
https://github.com/phil-opp/blog_os.git
synced 2025-12-16 14:27:49 +00:00
Compare commits
1 Commits
post-12-wi
...
post-06-st
| Author | SHA1 | Date | |
|---|---|---|---|
|
e3e8a3e112 |
33
Cargo.lock
generated
33
Cargo.lock
generated
@@ -27,9 +27,6 @@ version = "0.1.0"
|
||||
dependencies = [
|
||||
"bootloader",
|
||||
"lazy_static",
|
||||
"linked_list_allocator",
|
||||
"pc-keyboard",
|
||||
"pic8259_simple",
|
||||
"spin",
|
||||
"uart_16550",
|
||||
"volatile",
|
||||
@@ -51,12 +48,6 @@ dependencies = [
|
||||
"rustc_version",
|
||||
]
|
||||
|
||||
[[package]]
|
||||
name = "cpuio"
|
||||
version = "0.2.0"
|
||||
source = "registry+https://github.com/rust-lang/crates.io-index"
|
||||
checksum = "22b8e308ccfc5acf3b82f79c0eac444cf6114cb2ac67a230ca6c177210068daa"
|
||||
|
||||
[[package]]
|
||||
name = "lazy_static"
|
||||
version = "1.4.0"
|
||||
@@ -66,36 +57,12 @@ dependencies = [
|
||||
"spin",
|
||||
]
|
||||
|
||||
[[package]]
|
||||
name = "linked_list_allocator"
|
||||
version = "0.6.4"
|
||||
source = "registry+https://github.com/rust-lang/crates.io-index"
|
||||
checksum = "47314ec1d29aa869ee7cb5a5be57be9b1055c56567d59c3fb6689926743e0bea"
|
||||
dependencies = [
|
||||
"spin",
|
||||
]
|
||||
|
||||
[[package]]
|
||||
name = "nodrop"
|
||||
version = "0.1.14"
|
||||
source = "registry+https://github.com/rust-lang/crates.io-index"
|
||||
checksum = "72ef4a56884ca558e5ddb05a1d1e7e1bfd9a68d9ed024c21704cc98872dae1bb"
|
||||
|
||||
[[package]]
|
||||
name = "pc-keyboard"
|
||||
version = "0.3.1"
|
||||
source = "registry+https://github.com/rust-lang/crates.io-index"
|
||||
checksum = "fff50ab09ba31bcebc0669f4e64c0952fae1acdca9e6e0587e68e4e8443808ac"
|
||||
|
||||
[[package]]
|
||||
name = "pic8259_simple"
|
||||
version = "0.1.1"
|
||||
source = "registry+https://github.com/rust-lang/crates.io-index"
|
||||
checksum = "dc64b2fd10828da8521b6cdabe0679385d7d2a3a6d4c336b819d1fa31ba35c72"
|
||||
dependencies = [
|
||||
"cpuio",
|
||||
]
|
||||
|
||||
[[package]]
|
||||
name = "rustc_version"
|
||||
version = "0.2.3"
|
||||
|
||||
@@ -13,14 +13,11 @@ name = "stack_overflow"
|
||||
harness = false
|
||||
|
||||
[dependencies]
|
||||
bootloader = { version = "0.8.0", features = ["map_physical_memory"]}
|
||||
bootloader = "0.8.0"
|
||||
volatile = "0.2.6"
|
||||
spin = "0.5.2"
|
||||
x86_64 = "0.8.1"
|
||||
uart_16550 = "0.2.0"
|
||||
pic8259_simple = "0.1.1"
|
||||
pc-keyboard = "0.3.1"
|
||||
linked_list_allocator = "0.6.4"
|
||||
|
||||
[dependencies.lazy_static]
|
||||
version = "1.0"
|
||||
@@ -33,6 +30,3 @@ test-args = [
|
||||
"-display", "none"
|
||||
]
|
||||
test-success-exit-code = 33 # (0x10 << 1) | 1
|
||||
|
||||
[profile.release]
|
||||
lto = true
|
||||
@@ -1,10 +1,10 @@
|
||||
# Blog OS (Heap Allocation)
|
||||
# Blog OS (Double Faults)
|
||||
|
||||
[](https://github.com/phil-opp/blog_os/actions?query=workflow%3A%22Build+Code%22+branch%3Apost-10)
|
||||
[](https://github.com/phil-opp/blog_os/actions?query=workflow%3A%22Build+Code%22+branch%3Apost-06)
|
||||
|
||||
This repository contains the source code for the [Heap Allocation][post] post of the [Writing an OS in Rust](https://os.phil-opp.com) series.
|
||||
This repository contains the source code for the [Double Faults][post] post of the [Writing an OS in Rust](https://os.phil-opp.com) series.
|
||||
|
||||
[post]: https://os.phil-opp.com/heap-allocation/
|
||||
[post]: https://os.phil-opp.com/double-fault-exceptions/
|
||||
|
||||
**Check out the [master branch](https://github.com/phil-opp/blog_os) for more information.**
|
||||
|
||||
|
||||
@@ -1,58 +0,0 @@
|
||||
use super::{align_up, Locked};
|
||||
use alloc::alloc::{GlobalAlloc, Layout};
|
||||
use core::ptr;
|
||||
|
||||
pub struct BumpAllocator {
|
||||
heap_start: usize,
|
||||
heap_end: usize,
|
||||
next: usize,
|
||||
allocations: usize,
|
||||
}
|
||||
|
||||
impl BumpAllocator {
|
||||
/// Creates a new empty bump allocator.
|
||||
pub const fn new() -> Self {
|
||||
BumpAllocator {
|
||||
heap_start: 0,
|
||||
heap_end: 0,
|
||||
next: 0,
|
||||
allocations: 0,
|
||||
}
|
||||
}
|
||||
|
||||
/// Initializes the bump allocator with the given heap bounds.
|
||||
///
|
||||
/// This method is unsafe because the caller must ensure that the given
|
||||
/// memory range is unused. Also, this method must be called only once.
|
||||
pub unsafe fn init(&mut self, heap_start: usize, heap_size: usize) {
|
||||
self.heap_start = heap_start;
|
||||
self.heap_end = heap_start + heap_size;
|
||||
self.next = heap_start;
|
||||
}
|
||||
}
|
||||
|
||||
unsafe impl GlobalAlloc for Locked<BumpAllocator> {
|
||||
unsafe fn alloc(&self, layout: Layout) -> *mut u8 {
|
||||
let mut bump = self.lock(); // get a mutable reference
|
||||
|
||||
let alloc_start = align_up(bump.next, layout.align());
|
||||
let alloc_end = alloc_start + layout.size();
|
||||
|
||||
if alloc_end > bump.heap_end {
|
||||
ptr::null_mut() // out of memory
|
||||
} else {
|
||||
bump.next = alloc_end;
|
||||
bump.allocations += 1;
|
||||
alloc_start as *mut u8
|
||||
}
|
||||
}
|
||||
|
||||
unsafe fn dealloc(&self, _ptr: *mut u8, _layout: Layout) {
|
||||
let mut bump = self.lock(); // get a mutable reference
|
||||
|
||||
bump.allocations -= 1;
|
||||
if bump.allocations == 0 {
|
||||
bump.next = bump.heap_start;
|
||||
}
|
||||
}
|
||||
}
|
||||
@@ -1,102 +0,0 @@
|
||||
use super::Locked;
|
||||
use alloc::alloc::{GlobalAlloc, Layout};
|
||||
use core::{
|
||||
mem,
|
||||
ptr::{self, NonNull},
|
||||
};
|
||||
|
||||
/// The block sizes to use.
|
||||
///
|
||||
/// The sizes must each be power of 2 because they are also used as
|
||||
/// the block alignment (alignments must be always powers of 2).
|
||||
const BLOCK_SIZES: &[usize] = &[8, 16, 32, 64, 128, 256, 512, 1024, 2048];
|
||||
|
||||
/// Choose an appropriate block size for the given layout.
|
||||
///
|
||||
/// Returns an index into the `BLOCK_SIZES` array.
|
||||
fn list_index(layout: &Layout) -> Option<usize> {
|
||||
let required_block_size = layout.size().max(layout.align());
|
||||
BLOCK_SIZES.iter().position(|&s| s >= required_block_size)
|
||||
}
|
||||
|
||||
struct ListNode {
|
||||
next: Option<&'static mut ListNode>,
|
||||
}
|
||||
|
||||
pub struct FixedSizeBlockAllocator {
|
||||
list_heads: [Option<&'static mut ListNode>; BLOCK_SIZES.len()],
|
||||
fallback_allocator: linked_list_allocator::Heap,
|
||||
}
|
||||
|
||||
impl FixedSizeBlockAllocator {
|
||||
/// Creates an empty FixedSizeBlockAllocator.
|
||||
pub const fn new() -> Self {
|
||||
FixedSizeBlockAllocator {
|
||||
list_heads: [None; BLOCK_SIZES.len()],
|
||||
fallback_allocator: linked_list_allocator::Heap::empty(),
|
||||
}
|
||||
}
|
||||
|
||||
/// Initialize the allocator with the given heap bounds.
|
||||
///
|
||||
/// This function is unsafe because the caller must guarantee that the given
|
||||
/// heap bounds are valid and that the heap is unused. This method must be
|
||||
/// called only once.
|
||||
pub unsafe fn init(&mut self, heap_start: usize, heap_size: usize) {
|
||||
self.fallback_allocator.init(heap_start, heap_size);
|
||||
}
|
||||
|
||||
/// Allocates using the fallback allocator.
|
||||
fn fallback_alloc(&mut self, layout: Layout) -> *mut u8 {
|
||||
match self.fallback_allocator.allocate_first_fit(layout) {
|
||||
Ok(ptr) => ptr.as_ptr(),
|
||||
Err(_) => ptr::null_mut(),
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
unsafe impl GlobalAlloc for Locked<FixedSizeBlockAllocator> {
|
||||
unsafe fn alloc(&self, layout: Layout) -> *mut u8 {
|
||||
let mut allocator = self.lock();
|
||||
match list_index(&layout) {
|
||||
Some(index) => {
|
||||
match allocator.list_heads[index].take() {
|
||||
Some(node) => {
|
||||
allocator.list_heads[index] = node.next.take();
|
||||
node as *mut ListNode as *mut u8
|
||||
}
|
||||
None => {
|
||||
// no block exists in list => allocate new block
|
||||
let block_size = BLOCK_SIZES[index];
|
||||
// only works if all block sizes are a power of 2
|
||||
let block_align = block_size;
|
||||
let layout = Layout::from_size_align(block_size, block_align).unwrap();
|
||||
allocator.fallback_alloc(layout)
|
||||
}
|
||||
}
|
||||
}
|
||||
None => allocator.fallback_alloc(layout),
|
||||
}
|
||||
}
|
||||
|
||||
unsafe fn dealloc(&self, ptr: *mut u8, layout: Layout) {
|
||||
let mut allocator = self.lock();
|
||||
match list_index(&layout) {
|
||||
Some(index) => {
|
||||
let new_node = ListNode {
|
||||
next: allocator.list_heads[index].take(),
|
||||
};
|
||||
// verify that block has size and alignment required for storing node
|
||||
assert!(mem::size_of::<ListNode>() <= BLOCK_SIZES[index]);
|
||||
assert!(mem::align_of::<ListNode>() <= BLOCK_SIZES[index]);
|
||||
let new_node_ptr = ptr as *mut ListNode;
|
||||
new_node_ptr.write(new_node);
|
||||
allocator.list_heads[index] = Some(&mut *new_node_ptr);
|
||||
}
|
||||
None => {
|
||||
let ptr = NonNull::new(ptr).unwrap();
|
||||
allocator.fallback_allocator.deallocate(ptr, layout);
|
||||
}
|
||||
}
|
||||
}
|
||||
}
|
||||
@@ -1,145 +0,0 @@
|
||||
use super::{align_up, Locked};
|
||||
use alloc::alloc::{GlobalAlloc, Layout};
|
||||
use core::{mem, ptr};
|
||||
|
||||
struct ListNode {
|
||||
size: usize,
|
||||
next: Option<&'static mut ListNode>,
|
||||
}
|
||||
|
||||
impl ListNode {
|
||||
const fn new(size: usize) -> Self {
|
||||
ListNode { size, next: None }
|
||||
}
|
||||
|
||||
fn start_addr(&self) -> usize {
|
||||
self as *const Self as usize
|
||||
}
|
||||
|
||||
fn end_addr(&self) -> usize {
|
||||
self.start_addr() + self.size
|
||||
}
|
||||
}
|
||||
|
||||
pub struct LinkedListAllocator {
|
||||
head: ListNode,
|
||||
}
|
||||
|
||||
impl LinkedListAllocator {
|
||||
/// Creates an empty LinkedListAllocator.
|
||||
pub const fn new() -> Self {
|
||||
Self {
|
||||
head: ListNode::new(0),
|
||||
}
|
||||
}
|
||||
|
||||
/// Initialize the allocator with the given heap bounds.
|
||||
///
|
||||
/// This function is unsafe because the caller must guarantee that the given
|
||||
/// heap bounds are valid and that the heap is unused. This method must be
|
||||
/// called only once.
|
||||
pub unsafe fn init(&mut self, heap_start: usize, heap_size: usize) {
|
||||
self.add_free_region(heap_start, heap_size);
|
||||
}
|
||||
|
||||
/// Adds the given memory region to the front of the list.
|
||||
unsafe fn add_free_region(&mut self, addr: usize, size: usize) {
|
||||
// ensure that the freed region is capable of holding ListNode
|
||||
assert!(align_up(addr, mem::align_of::<ListNode>()) == addr);
|
||||
assert!(size >= mem::size_of::<ListNode>());
|
||||
|
||||
// create a new list node and append it at the start of the list
|
||||
let mut node = ListNode::new(size);
|
||||
node.next = self.head.next.take();
|
||||
let node_ptr = addr as *mut ListNode;
|
||||
node_ptr.write(node);
|
||||
self.head.next = Some(&mut *node_ptr)
|
||||
}
|
||||
|
||||
/// Looks for a free region with the given size and alignment and removes
|
||||
/// it from the list.
|
||||
///
|
||||
/// Returns a tuple of the list node and the start address of the allocation.
|
||||
fn find_region(&mut self, size: usize, align: usize) -> Option<(&'static mut ListNode, usize)> {
|
||||
// reference to current list node, updated for each iteration
|
||||
let mut current = &mut self.head;
|
||||
// look for a large enough memory region in linked list
|
||||
while let Some(ref mut region) = current.next {
|
||||
if let Ok(alloc_start) = Self::alloc_from_region(®ion, size, align) {
|
||||
// region suitable for allocation -> remove node from list
|
||||
let next = region.next.take();
|
||||
let ret = Some((current.next.take().unwrap(), alloc_start));
|
||||
current.next = next;
|
||||
return ret;
|
||||
} else {
|
||||
// region not suitable -> continue with next region
|
||||
current = current.next.as_mut().unwrap();
|
||||
}
|
||||
}
|
||||
|
||||
// no suitable region found
|
||||
None
|
||||
}
|
||||
|
||||
/// Try to use the given region for an allocation with given size and alignment.
|
||||
///
|
||||
/// Returns the allocation start address on success.
|
||||
fn alloc_from_region(region: &ListNode, size: usize, align: usize) -> Result<usize, ()> {
|
||||
let alloc_start = align_up(region.start_addr(), align);
|
||||
let alloc_end = alloc_start + size;
|
||||
|
||||
if alloc_end > region.end_addr() {
|
||||
// region too small
|
||||
return Err(());
|
||||
}
|
||||
|
||||
let excess_size = region.end_addr() - alloc_end;
|
||||
if excess_size > 0 && excess_size < mem::size_of::<ListNode>() {
|
||||
// rest of region too small to hold a ListNode (required because the
|
||||
// allocation splits the region in a used and a free part)
|
||||
return Err(());
|
||||
}
|
||||
|
||||
// region suitable for allocation
|
||||
Ok(alloc_start)
|
||||
}
|
||||
|
||||
/// Adjust the given layout so that the resulting allocated memory
|
||||
/// region is also capable of storing a `ListNode`.
|
||||
///
|
||||
/// Returns the adjusted size and alignment as a (size, align) tuple.
|
||||
fn size_align(layout: Layout) -> (usize, usize) {
|
||||
let layout = layout
|
||||
.align_to(mem::align_of::<ListNode>())
|
||||
.expect("adjusting alignment failed")
|
||||
.pad_to_align();
|
||||
let size = layout.size().max(mem::size_of::<ListNode>());
|
||||
(size, layout.align())
|
||||
}
|
||||
}
|
||||
|
||||
unsafe impl GlobalAlloc for Locked<LinkedListAllocator> {
|
||||
unsafe fn alloc(&self, layout: Layout) -> *mut u8 {
|
||||
// perform layout adjustments
|
||||
let (size, align) = LinkedListAllocator::size_align(layout);
|
||||
let mut allocator = self.inner.lock();
|
||||
|
||||
if let Some((region, alloc_start)) = allocator.find_region(size, align) {
|
||||
let alloc_end = alloc_start + size;
|
||||
let excess_size = region.end_addr() - alloc_end;
|
||||
if excess_size > 0 {
|
||||
allocator.add_free_region(alloc_end, excess_size);
|
||||
}
|
||||
alloc_start as *mut u8
|
||||
} else {
|
||||
ptr::null_mut()
|
||||
}
|
||||
}
|
||||
|
||||
unsafe fn dealloc(&self, ptr: *mut u8, layout: Layout) {
|
||||
// perform layout adjustments
|
||||
let (size, _) = LinkedListAllocator::size_align(layout);
|
||||
|
||||
self.inner.lock().add_free_region(ptr as usize, size)
|
||||
}
|
||||
}
|
||||
@@ -1,84 +0,0 @@
|
||||
use alloc::alloc::{GlobalAlloc, Layout};
|
||||
use core::ptr::null_mut;
|
||||
use fixed_size_block::FixedSizeBlockAllocator;
|
||||
use x86_64::{
|
||||
structures::paging::{
|
||||
mapper::MapToError, FrameAllocator, Mapper, Page, PageTableFlags, Size4KiB,
|
||||
},
|
||||
VirtAddr,
|
||||
};
|
||||
|
||||
pub mod bump;
|
||||
pub mod fixed_size_block;
|
||||
pub mod linked_list;
|
||||
|
||||
pub const HEAP_START: usize = 0x_4444_4444_0000;
|
||||
pub const HEAP_SIZE: usize = 100 * 1024; // 100 KiB
|
||||
|
||||
#[global_allocator]
|
||||
static ALLOCATOR: Locked<FixedSizeBlockAllocator> = Locked::new(FixedSizeBlockAllocator::new());
|
||||
|
||||
pub fn init_heap(
|
||||
mapper: &mut impl Mapper<Size4KiB>,
|
||||
frame_allocator: &mut impl FrameAllocator<Size4KiB>,
|
||||
) -> Result<(), MapToError> {
|
||||
let page_range = {
|
||||
let heap_start = VirtAddr::new(HEAP_START as u64);
|
||||
let heap_end = heap_start + HEAP_SIZE - 1u64;
|
||||
let heap_start_page = Page::containing_address(heap_start);
|
||||
let heap_end_page = Page::containing_address(heap_end);
|
||||
Page::range_inclusive(heap_start_page, heap_end_page)
|
||||
};
|
||||
|
||||
for page in page_range {
|
||||
let frame = frame_allocator
|
||||
.allocate_frame()
|
||||
.ok_or(MapToError::FrameAllocationFailed)?;
|
||||
let flags = PageTableFlags::PRESENT | PageTableFlags::WRITABLE;
|
||||
mapper.map_to(page, frame, flags, frame_allocator)?.flush();
|
||||
}
|
||||
|
||||
unsafe {
|
||||
ALLOCATOR.lock().init(HEAP_START, HEAP_SIZE);
|
||||
}
|
||||
|
||||
Ok(())
|
||||
}
|
||||
|
||||
pub struct Dummy;
|
||||
|
||||
unsafe impl GlobalAlloc for Dummy {
|
||||
unsafe fn alloc(&self, _layout: Layout) -> *mut u8 {
|
||||
null_mut()
|
||||
}
|
||||
|
||||
unsafe fn dealloc(&self, _ptr: *mut u8, _layout: Layout) {
|
||||
panic!("dealloc should be never called")
|
||||
}
|
||||
}
|
||||
|
||||
/// A wrapper around spin::Mutex to permit trait implementations.
|
||||
pub struct Locked<A> {
|
||||
inner: spin::Mutex<A>,
|
||||
}
|
||||
|
||||
impl<A> Locked<A> {
|
||||
pub const fn new(inner: A) -> Self {
|
||||
Locked {
|
||||
inner: spin::Mutex::new(inner),
|
||||
}
|
||||
}
|
||||
|
||||
pub fn lock(&self) -> spin::MutexGuard<A> {
|
||||
self.inner.lock()
|
||||
}
|
||||
}
|
||||
|
||||
fn align_up(addr: usize, align: usize) -> usize {
|
||||
let remainder = addr % align;
|
||||
if remainder == 0 {
|
||||
addr // addr already aligned
|
||||
} else {
|
||||
addr - remainder + align
|
||||
}
|
||||
}
|
||||
@@ -10,7 +10,11 @@ lazy_static! {
|
||||
let mut tss = TaskStateSegment::new();
|
||||
tss.interrupt_stack_table[DOUBLE_FAULT_IST_INDEX as usize] = {
|
||||
const STACK_SIZE: usize = 4096;
|
||||
static mut STACK: [u8; STACK_SIZE] = [0; STACK_SIZE];
|
||||
|
||||
#[repr(align(16))]
|
||||
struct Stack([u8; STACK_SIZE]);
|
||||
|
||||
static mut STACK: Stack = Stack([0; STACK_SIZE]);
|
||||
|
||||
let stack_start = VirtAddr::from_ptr(unsafe { &STACK });
|
||||
let stack_end = stack_start + STACK_SIZE;
|
||||
|
||||
@@ -1,44 +1,16 @@
|
||||
use crate::{gdt, hlt_loop, print, println};
|
||||
use crate::{gdt, println};
|
||||
use lazy_static::lazy_static;
|
||||
use pic8259_simple::ChainedPics;
|
||||
use spin;
|
||||
use x86_64::structures::idt::{InterruptDescriptorTable, InterruptStackFrame, PageFaultErrorCode};
|
||||
|
||||
pub const PIC_1_OFFSET: u8 = 32;
|
||||
pub const PIC_2_OFFSET: u8 = PIC_1_OFFSET + 8;
|
||||
|
||||
#[derive(Debug, Clone, Copy)]
|
||||
#[repr(u8)]
|
||||
pub enum InterruptIndex {
|
||||
Timer = PIC_1_OFFSET,
|
||||
Keyboard,
|
||||
}
|
||||
|
||||
impl InterruptIndex {
|
||||
fn as_u8(self) -> u8 {
|
||||
self as u8
|
||||
}
|
||||
|
||||
fn as_usize(self) -> usize {
|
||||
usize::from(self.as_u8())
|
||||
}
|
||||
}
|
||||
|
||||
pub static PICS: spin::Mutex<ChainedPics> =
|
||||
spin::Mutex::new(unsafe { ChainedPics::new(PIC_1_OFFSET, PIC_2_OFFSET) });
|
||||
use x86_64::structures::idt::{InterruptDescriptorTable, InterruptStackFrame};
|
||||
|
||||
lazy_static! {
|
||||
static ref IDT: InterruptDescriptorTable = {
|
||||
let mut idt = InterruptDescriptorTable::new();
|
||||
idt.breakpoint.set_handler_fn(breakpoint_handler);
|
||||
idt.page_fault.set_handler_fn(page_fault_handler);
|
||||
unsafe {
|
||||
idt.double_fault
|
||||
.set_handler_fn(double_fault_handler)
|
||||
.set_stack_index(gdt::DOUBLE_FAULT_IST_INDEX);
|
||||
}
|
||||
idt[InterruptIndex::Timer.as_usize()].set_handler_fn(timer_interrupt_handler);
|
||||
idt[InterruptIndex::Keyboard.as_usize()].set_handler_fn(keyboard_interrupt_handler);
|
||||
idt
|
||||
};
|
||||
}
|
||||
@@ -51,19 +23,6 @@ extern "x86-interrupt" fn breakpoint_handler(stack_frame: &mut InterruptStackFra
|
||||
println!("EXCEPTION: BREAKPOINT\n{:#?}", stack_frame);
|
||||
}
|
||||
|
||||
extern "x86-interrupt" fn page_fault_handler(
|
||||
stack_frame: &mut InterruptStackFrame,
|
||||
error_code: PageFaultErrorCode,
|
||||
) {
|
||||
use x86_64::registers::control::Cr2;
|
||||
|
||||
println!("EXCEPTION: PAGE FAULT");
|
||||
println!("Accessed Address: {:?}", Cr2::read());
|
||||
println!("Error Code: {:?}", error_code);
|
||||
println!("{:#?}", stack_frame);
|
||||
hlt_loop();
|
||||
}
|
||||
|
||||
extern "x86-interrupt" fn double_fault_handler(
|
||||
stack_frame: &mut InterruptStackFrame,
|
||||
_error_code: u64,
|
||||
@@ -71,44 +30,6 @@ extern "x86-interrupt" fn double_fault_handler(
|
||||
panic!("EXCEPTION: DOUBLE FAULT\n{:#?}", stack_frame);
|
||||
}
|
||||
|
||||
extern "x86-interrupt" fn timer_interrupt_handler(_stack_frame: &mut InterruptStackFrame) {
|
||||
print!(".");
|
||||
unsafe {
|
||||
PICS.lock()
|
||||
.notify_end_of_interrupt(InterruptIndex::Timer.as_u8());
|
||||
}
|
||||
crate::multitasking::invoke_scheduler();
|
||||
}
|
||||
|
||||
extern "x86-interrupt" fn keyboard_interrupt_handler(_stack_frame: &mut InterruptStackFrame) {
|
||||
use pc_keyboard::{layouts, DecodedKey, Keyboard, ScancodeSet1};
|
||||
use spin::Mutex;
|
||||
use x86_64::instructions::port::Port;
|
||||
|
||||
lazy_static! {
|
||||
static ref KEYBOARD: Mutex<Keyboard<layouts::Us104Key, ScancodeSet1>> =
|
||||
Mutex::new(Keyboard::new(layouts::Us104Key, ScancodeSet1));
|
||||
}
|
||||
|
||||
let mut keyboard = KEYBOARD.lock();
|
||||
let mut port = Port::new(0x60);
|
||||
|
||||
let scancode: u8 = unsafe { port.read() };
|
||||
if let Ok(Some(key_event)) = keyboard.add_byte(scancode) {
|
||||
if let Some(key) = keyboard.process_keyevent(key_event) {
|
||||
match key {
|
||||
DecodedKey::Unicode(character) => print!("{}", character),
|
||||
DecodedKey::RawKey(key) => print!("{:?}", key),
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
unsafe {
|
||||
PICS.lock()
|
||||
.notify_end_of_interrupt(InterruptIndex::Keyboard.as_u8());
|
||||
}
|
||||
}
|
||||
|
||||
#[cfg(test)]
|
||||
use crate::{serial_print, serial_println};
|
||||
|
||||
|
||||
41
src/lib.rs
41
src/lib.rs
@@ -2,36 +2,19 @@
|
||||
#![cfg_attr(test, no_main)]
|
||||
#![feature(custom_test_frameworks)]
|
||||
#![feature(abi_x86_interrupt)]
|
||||
#![feature(alloc_error_handler)]
|
||||
#![feature(const_fn)]
|
||||
#![feature(alloc_layout_extra)]
|
||||
#![feature(const_in_array_repeat_expressions)]
|
||||
#![feature(global_asm)]
|
||||
#![feature(asm)]
|
||||
#![feature(raw)]
|
||||
#![feature(never_type)]
|
||||
#![feature(naked_functions)]
|
||||
#![feature(option_expect_none)]
|
||||
#![test_runner(crate::test_runner)]
|
||||
#![reexport_test_harness_main = "test_main"]
|
||||
|
||||
extern crate alloc;
|
||||
|
||||
use core::panic::PanicInfo;
|
||||
|
||||
pub mod allocator;
|
||||
pub mod gdt;
|
||||
pub mod interrupts;
|
||||
pub mod memory;
|
||||
pub mod multitasking;
|
||||
pub mod serial;
|
||||
pub mod vga_buffer;
|
||||
|
||||
pub fn init() {
|
||||
gdt::init();
|
||||
interrupts::init_idt();
|
||||
unsafe { interrupts::PICS.lock().initialize() };
|
||||
x86_64::instructions::interrupts::enable();
|
||||
}
|
||||
|
||||
pub fn test_runner(tests: &[&dyn Fn()]) {
|
||||
@@ -46,7 +29,7 @@ pub fn test_panic_handler(info: &PanicInfo) -> ! {
|
||||
serial_println!("[failed]\n");
|
||||
serial_println!("Error: {}\n", info);
|
||||
exit_qemu(QemuExitCode::Failed);
|
||||
hlt_loop();
|
||||
loop {}
|
||||
}
|
||||
|
||||
#[derive(Debug, Clone, Copy, PartialEq, Eq)]
|
||||
@@ -65,24 +48,13 @@ pub fn exit_qemu(exit_code: QemuExitCode) {
|
||||
}
|
||||
}
|
||||
|
||||
pub fn hlt_loop() -> ! {
|
||||
loop {
|
||||
x86_64::instructions::hlt();
|
||||
}
|
||||
}
|
||||
|
||||
#[cfg(test)]
|
||||
use bootloader::{entry_point, BootInfo};
|
||||
|
||||
#[cfg(test)]
|
||||
entry_point!(test_kernel_main);
|
||||
|
||||
/// Entry point for `cargo xtest`
|
||||
#[cfg(test)]
|
||||
fn test_kernel_main(_boot_info: &'static BootInfo) -> ! {
|
||||
#[no_mangle]
|
||||
pub extern "C" fn _start() -> ! {
|
||||
init();
|
||||
test_main();
|
||||
hlt_loop();
|
||||
loop {}
|
||||
}
|
||||
|
||||
#[cfg(test)]
|
||||
@@ -90,8 +62,3 @@ fn test_kernel_main(_boot_info: &'static BootInfo) -> ! {
|
||||
fn panic(info: &PanicInfo) -> ! {
|
||||
test_panic_handler(info)
|
||||
}
|
||||
|
||||
#[alloc_error_handler]
|
||||
fn alloc_error_handler(layout: alloc::alloc::Layout) -> ! {
|
||||
panic!("allocation error: {:?}", layout)
|
||||
}
|
||||
|
||||
83
src/main.rs
83
src/main.rs
@@ -4,98 +4,35 @@
|
||||
#![test_runner(blog_os::test_runner)]
|
||||
#![reexport_test_harness_main = "test_main"]
|
||||
|
||||
extern crate alloc;
|
||||
|
||||
use alloc::{boxed::Box, rc::Rc, vec, vec::Vec};
|
||||
use blog_os::multitasking::{self, thread::Thread, with_scheduler};
|
||||
use blog_os::{print, println};
|
||||
use bootloader::{entry_point, BootInfo};
|
||||
use blog_os::println;
|
||||
use core::panic::PanicInfo;
|
||||
|
||||
entry_point!(kernel_main);
|
||||
|
||||
fn kernel_main(boot_info: &'static BootInfo) -> ! {
|
||||
use blog_os::allocator;
|
||||
use blog_os::memory::{self, BootInfoFrameAllocator};
|
||||
use x86_64::VirtAddr;
|
||||
|
||||
#[no_mangle]
|
||||
pub extern "C" fn _start() -> ! {
|
||||
println!("Hello World{}", "!");
|
||||
|
||||
blog_os::init();
|
||||
|
||||
let phys_mem_offset = VirtAddr::new(boot_info.physical_memory_offset);
|
||||
let mut mapper = unsafe { memory::init(phys_mem_offset) };
|
||||
let mut frame_allocator = unsafe { BootInfoFrameAllocator::init(&boot_info.memory_map) };
|
||||
|
||||
allocator::init_heap(&mut mapper, &mut frame_allocator).expect("heap initialization failed");
|
||||
|
||||
// allocate a number on the heap
|
||||
let heap_value = Box::new(41);
|
||||
println!("heap_value at {:p}", heap_value);
|
||||
|
||||
// create a dynamically sized vector
|
||||
let mut vec = Vec::new();
|
||||
for i in 0..500 {
|
||||
vec.push(i);
|
||||
fn stack_overflow() {
|
||||
stack_overflow(); // for each recursion, the return address is pushed
|
||||
}
|
||||
println!("vec at {:p}", vec.as_slice());
|
||||
|
||||
// create a reference counted vector -> will be freed when count reaches 0
|
||||
let reference_counted = Rc::new(vec![1, 2, 3]);
|
||||
let cloned_reference = reference_counted.clone();
|
||||
println!(
|
||||
"current reference count is {}",
|
||||
Rc::strong_count(&cloned_reference)
|
||||
);
|
||||
core::mem::drop(reference_counted);
|
||||
println!(
|
||||
"reference count is {} now",
|
||||
Rc::strong_count(&cloned_reference)
|
||||
);
|
||||
// uncomment line below to trigger a stack overflow
|
||||
// stack_overflow();
|
||||
|
||||
#[cfg(test)]
|
||||
test_main();
|
||||
|
||||
let idle_thread = Thread::create(idle_thread, 2, &mut mapper, &mut frame_allocator).unwrap();
|
||||
with_scheduler(|s| s.set_idle_thread(idle_thread));
|
||||
|
||||
for _ in 0..10 {
|
||||
let thread = Thread::create(thread_entry, 2, &mut mapper, &mut frame_allocator).unwrap();
|
||||
with_scheduler(|s| s.add_new_thread(thread));
|
||||
}
|
||||
let thread =
|
||||
Thread::create_from_closure(|| thread_entry(), 2, &mut mapper, &mut frame_allocator)
|
||||
.unwrap();
|
||||
with_scheduler(|s| s.add_new_thread(thread));
|
||||
|
||||
println!("It did not crash!");
|
||||
thread_entry();
|
||||
}
|
||||
|
||||
fn idle_thread() -> ! {
|
||||
loop {
|
||||
x86_64::instructions::hlt();
|
||||
multitasking::yield_now();
|
||||
}
|
||||
}
|
||||
|
||||
fn thread_entry() -> ! {
|
||||
let thread_id = with_scheduler(|s| s.current_thread_id()).as_u64();
|
||||
for _ in 0..=thread_id {
|
||||
print!("{}", thread_id);
|
||||
x86_64::instructions::hlt();
|
||||
}
|
||||
multitasking::exit_thread();
|
||||
loop {}
|
||||
}
|
||||
|
||||
/// This function is called on panic.
|
||||
#[cfg(not(test))]
|
||||
#[panic_handler]
|
||||
fn panic(info: &PanicInfo) -> ! {
|
||||
unsafe {
|
||||
blog_os::vga_buffer::WRITER.force_unlock();
|
||||
}
|
||||
println!("{}", info);
|
||||
blog_os::hlt_loop();
|
||||
loop {}
|
||||
}
|
||||
|
||||
#[cfg(test)]
|
||||
|
||||
154
src/memory.rs
154
src/memory.rs
@@ -1,154 +0,0 @@
|
||||
use bootloader::bootinfo::{MemoryMap, MemoryRegionType};
|
||||
use x86_64::{
|
||||
structures::paging::{
|
||||
mapper, FrameAllocator, Mapper, OffsetPageTable, Page, PageTable, PhysFrame, Size4KiB,
|
||||
UnusedPhysFrame,
|
||||
},
|
||||
PhysAddr, VirtAddr,
|
||||
};
|
||||
|
||||
/// Initialize a new OffsetPageTable.
|
||||
///
|
||||
/// This function is unsafe because the caller must guarantee that the
|
||||
/// complete physical memory is mapped to virtual memory at the passed
|
||||
/// `physical_memory_offset`. Also, this function must be only called once
|
||||
/// to avoid aliasing `&mut` references (which is undefined behavior).
|
||||
pub unsafe fn init(physical_memory_offset: VirtAddr) -> OffsetPageTable<'static> {
|
||||
let level_4_table = active_level_4_table(physical_memory_offset);
|
||||
OffsetPageTable::new(level_4_table, physical_memory_offset)
|
||||
}
|
||||
|
||||
/// Returns a mutable reference to the active level 4 table.
|
||||
///
|
||||
/// This function is unsafe because the caller must guarantee that the
|
||||
/// complete physical memory is mapped to virtual memory at the passed
|
||||
/// `physical_memory_offset`. Also, this function must be only called once
|
||||
/// to avoid aliasing `&mut` references (which is undefined behavior).
|
||||
unsafe fn active_level_4_table(physical_memory_offset: VirtAddr) -> &'static mut PageTable {
|
||||
use x86_64::registers::control::Cr3;
|
||||
|
||||
let (level_4_table_frame, _) = Cr3::read();
|
||||
|
||||
let phys = level_4_table_frame.start_address();
|
||||
let virt = physical_memory_offset + phys.as_u64();
|
||||
let page_table_ptr: *mut PageTable = virt.as_mut_ptr();
|
||||
|
||||
&mut *page_table_ptr // unsafe
|
||||
}
|
||||
|
||||
#[derive(Debug, Clone, Copy, PartialEq, Eq)]
|
||||
pub struct StackBounds {
|
||||
start: VirtAddr,
|
||||
end: VirtAddr,
|
||||
}
|
||||
|
||||
impl StackBounds {
|
||||
pub fn start(&self) -> VirtAddr {
|
||||
self.start
|
||||
}
|
||||
|
||||
pub fn end(&self) -> VirtAddr {
|
||||
self.end
|
||||
}
|
||||
}
|
||||
|
||||
pub fn alloc_stack(
|
||||
size_in_pages: u64,
|
||||
mapper: &mut impl Mapper<Size4KiB>,
|
||||
frame_allocator: &mut impl FrameAllocator<Size4KiB>,
|
||||
) -> Result<StackBounds, mapper::MapToError> {
|
||||
use core::sync::atomic::{AtomicU64, Ordering};
|
||||
use x86_64::structures::paging::PageTableFlags as Flags;
|
||||
|
||||
static STACK_ALLOC_NEXT: AtomicU64 = AtomicU64::new(0x_5555_5555_0000);
|
||||
|
||||
let guard_page_start = STACK_ALLOC_NEXT.fetch_add(
|
||||
(size_in_pages + 1) * Page::<Size4KiB>::SIZE,
|
||||
Ordering::SeqCst,
|
||||
);
|
||||
let guard_page = Page::from_start_address(VirtAddr::new(guard_page_start))
|
||||
.expect("`STACK_ALLOC_NEXT` not page aligned");
|
||||
|
||||
let stack_start = guard_page + 1;
|
||||
let stack_end = stack_start + size_in_pages;
|
||||
let flags = Flags::PRESENT | Flags::WRITABLE;
|
||||
for page in Page::range(stack_start, stack_end) {
|
||||
let frame = frame_allocator
|
||||
.allocate_frame()
|
||||
.ok_or(mapper::MapToError::FrameAllocationFailed)?;
|
||||
mapper.map_to(page, frame, flags, frame_allocator)?.flush();
|
||||
}
|
||||
Ok(StackBounds {
|
||||
start: stack_start.start_address(),
|
||||
end: stack_end.start_address(),
|
||||
})
|
||||
}
|
||||
|
||||
/// Creates an example mapping for the given page to frame `0xb8000`.
|
||||
pub fn create_example_mapping(
|
||||
page: Page,
|
||||
mapper: &mut OffsetPageTable,
|
||||
frame_allocator: &mut impl FrameAllocator<Size4KiB>,
|
||||
) {
|
||||
use x86_64::structures::paging::PageTableFlags as Flags;
|
||||
|
||||
let frame = PhysFrame::containing_address(PhysAddr::new(0xb8000));
|
||||
// FIXME: ONLY FOR TEMPORARY TESTING
|
||||
let unused_frame = unsafe { UnusedPhysFrame::new(frame) };
|
||||
let flags = Flags::PRESENT | Flags::WRITABLE;
|
||||
|
||||
let map_to_result = mapper.map_to(page, unused_frame, flags, frame_allocator);
|
||||
map_to_result.expect("map_to failed").flush();
|
||||
}
|
||||
|
||||
/// A FrameAllocator that always returns `None`.
|
||||
pub struct EmptyFrameAllocator;
|
||||
|
||||
unsafe impl FrameAllocator<Size4KiB> for EmptyFrameAllocator {
|
||||
fn allocate_frame(&mut self) -> Option<UnusedPhysFrame> {
|
||||
None
|
||||
}
|
||||
}
|
||||
|
||||
/// A FrameAllocator that returns usable frames from the bootloader's memory map.
|
||||
pub struct BootInfoFrameAllocator {
|
||||
memory_map: &'static MemoryMap,
|
||||
next: usize,
|
||||
}
|
||||
|
||||
impl BootInfoFrameAllocator {
|
||||
/// Create a FrameAllocator from the passed memory map.
|
||||
///
|
||||
/// This function is unsafe because the caller must guarantee that the passed
|
||||
/// memory map is valid. The main requirement is that all frames that are marked
|
||||
/// as `USABLE` in it are really unused.
|
||||
pub unsafe fn init(memory_map: &'static MemoryMap) -> Self {
|
||||
BootInfoFrameAllocator {
|
||||
memory_map,
|
||||
next: 0,
|
||||
}
|
||||
}
|
||||
|
||||
/// Returns an iterator over the usable frames specified in the memory map.
|
||||
fn usable_frames(&self) -> impl Iterator<Item = UnusedPhysFrame> {
|
||||
// get usable regions from memory map
|
||||
let regions = self.memory_map.iter();
|
||||
let usable_regions = regions.filter(|r| r.region_type == MemoryRegionType::Usable);
|
||||
// map each region to its address range
|
||||
let addr_ranges = usable_regions.map(|r| r.range.start_addr()..r.range.end_addr());
|
||||
// transform to an iterator of frame start addresses
|
||||
let frame_addresses = addr_ranges.flat_map(|r| r.step_by(4096));
|
||||
// create `PhysFrame` types from the start addresses
|
||||
let frames = frame_addresses.map(|addr| PhysFrame::containing_address(PhysAddr::new(addr)));
|
||||
// we know that the frames are really unused
|
||||
frames.map(|f| unsafe { UnusedPhysFrame::new(f) })
|
||||
}
|
||||
}
|
||||
|
||||
unsafe impl FrameAllocator<Size4KiB> for BootInfoFrameAllocator {
|
||||
fn allocate_frame(&mut self) -> Option<UnusedPhysFrame> {
|
||||
let frame = self.usable_frames().nth(self.next);
|
||||
self.next += 1;
|
||||
frame
|
||||
}
|
||||
}
|
||||
@@ -1,105 +0,0 @@
|
||||
use super::{with_scheduler, SwitchReason};
|
||||
use crate::multitasking::thread::ThreadId;
|
||||
use alloc::boxed::Box;
|
||||
use core::mem;
|
||||
use core::raw::TraitObject;
|
||||
use x86_64::VirtAddr;
|
||||
|
||||
pub struct Stack {
|
||||
pointer: VirtAddr,
|
||||
}
|
||||
|
||||
impl Stack {
|
||||
pub unsafe fn new(stack_pointer: VirtAddr) -> Self {
|
||||
Stack {
|
||||
pointer: stack_pointer,
|
||||
}
|
||||
}
|
||||
|
||||
pub fn get_stack_pointer(self) -> VirtAddr {
|
||||
self.pointer
|
||||
}
|
||||
|
||||
pub fn set_up_for_closure(&mut self, closure: Box<dyn FnOnce() -> !>) {
|
||||
let trait_object: TraitObject = unsafe { mem::transmute(closure) };
|
||||
unsafe { self.push(trait_object.data) };
|
||||
unsafe { self.push(trait_object.vtable) };
|
||||
|
||||
self.set_up_for_entry_point(call_closure_entry);
|
||||
}
|
||||
|
||||
pub fn set_up_for_entry_point(&mut self, entry_point: fn() -> !) {
|
||||
unsafe { self.push(entry_point) };
|
||||
let rflags: u64 = 0x200;
|
||||
unsafe { self.push(rflags) };
|
||||
}
|
||||
|
||||
unsafe fn push<T>(&mut self, value: T) {
|
||||
self.pointer -= core::mem::size_of::<T>();
|
||||
let ptr: *mut T = self.pointer.as_mut_ptr();
|
||||
ptr.write(value);
|
||||
}
|
||||
}
|
||||
|
||||
pub unsafe fn context_switch_to(
|
||||
new_stack_pointer: VirtAddr,
|
||||
prev_thread_id: ThreadId,
|
||||
switch_reason: SwitchReason,
|
||||
) {
|
||||
asm!(
|
||||
"call asm_context_switch"
|
||||
:
|
||||
: "{rdi}"(new_stack_pointer), "{rsi}"(prev_thread_id), "{rdx}"(switch_reason as u64)
|
||||
: "rax", "rbx", "rcx", "rdx", "rsi", "rdi", "rbp", "r8", "r9", "r10",
|
||||
"r11", "r12", "r13", "r14", "r15", "rflags", "memory"
|
||||
: "intel", "volatile"
|
||||
);
|
||||
}
|
||||
|
||||
global_asm!(
|
||||
"
|
||||
.intel_syntax noprefix
|
||||
|
||||
// asm_context_switch(stack_pointer: u64, thread_id: u64)
|
||||
asm_context_switch:
|
||||
pushfq
|
||||
|
||||
mov rax, rsp
|
||||
mov rsp, rdi
|
||||
|
||||
mov rdi, rax
|
||||
call add_paused_thread
|
||||
|
||||
popfq
|
||||
ret
|
||||
"
|
||||
);
|
||||
|
||||
#[no_mangle]
|
||||
pub extern "C" fn add_paused_thread(
|
||||
paused_stack_pointer: VirtAddr,
|
||||
paused_thread_id: ThreadId,
|
||||
switch_reason: SwitchReason,
|
||||
) {
|
||||
with_scheduler(|s| s.add_paused_thread(paused_stack_pointer, paused_thread_id, switch_reason));
|
||||
}
|
||||
|
||||
#[naked]
|
||||
fn call_closure_entry() -> ! {
|
||||
unsafe {
|
||||
asm!("
|
||||
pop rsi
|
||||
pop rdi
|
||||
call call_closure
|
||||
" ::: "mem" : "intel", "volatile")
|
||||
};
|
||||
unreachable!();
|
||||
}
|
||||
|
||||
// no_mangle required because of https://github.com/rust-lang/rust/issues/68136
|
||||
#[no_mangle]
|
||||
extern "C" fn call_closure(data: *mut (), vtable: *mut ()) -> ! {
|
||||
let trait_object = TraitObject { data, vtable };
|
||||
let f: Box<dyn FnOnce() -> !> = unsafe { mem::transmute(trait_object) };
|
||||
f()
|
||||
}
|
||||
@@ -1,57 +0,0 @@
|
||||
use scheduler::Scheduler;
|
||||
|
||||
pub mod context_switch;
|
||||
pub mod scheduler;
|
||||
pub mod thread;
|
||||
|
||||
static SCHEDULER: spin::Mutex<Option<Scheduler>> = spin::Mutex::new(None);
|
||||
|
||||
#[repr(u64)]
|
||||
pub enum SwitchReason {
|
||||
Paused,
|
||||
Yield,
|
||||
Blocked,
|
||||
Exit,
|
||||
}
|
||||
|
||||
pub fn invoke_scheduler() {
|
||||
let next = SCHEDULER
|
||||
.try_lock()
|
||||
.and_then(|mut scheduler| scheduler.as_mut().and_then(|s| s.schedule()));
|
||||
if let Some((next_stack_pointer, prev_thread_id)) = next {
|
||||
unsafe {
|
||||
context_switch::context_switch_to(
|
||||
next_stack_pointer,
|
||||
prev_thread_id,
|
||||
SwitchReason::Paused,
|
||||
)
|
||||
};
|
||||
}
|
||||
}
|
||||
|
||||
pub fn exit_thread() -> ! {
|
||||
synchronous_context_switch(SwitchReason::Exit).expect("can't exit last thread");
|
||||
unreachable!("finished thread continued");
|
||||
}
|
||||
|
||||
pub fn yield_now() {
|
||||
let _ = synchronous_context_switch(SwitchReason::Yield);
|
||||
}
|
||||
|
||||
fn synchronous_context_switch(reason: SwitchReason) -> Result<(), ()> {
|
||||
let next = with_scheduler(|s| s.schedule());
|
||||
match next {
|
||||
Some((next_stack_pointer, prev_thread_id)) => unsafe {
|
||||
context_switch::context_switch_to(next_stack_pointer, prev_thread_id, reason);
|
||||
Ok(())
|
||||
},
|
||||
None => Err(()),
|
||||
}
|
||||
}
|
||||
|
||||
pub fn with_scheduler<F, T>(f: F) -> T
|
||||
where
|
||||
F: FnOnce(&mut Scheduler) -> T,
|
||||
{
|
||||
f(SCHEDULER.lock().get_or_insert_with(Scheduler::new))
|
||||
}
|
||||
@@ -1,122 +0,0 @@
|
||||
use super::SwitchReason;
|
||||
use crate::multitasking::thread::{Thread, ThreadId};
|
||||
use alloc::collections::{BTreeMap, BTreeSet, VecDeque};
|
||||
use core::mem;
|
||||
use x86_64::VirtAddr;
|
||||
|
||||
pub struct Scheduler {
|
||||
threads: BTreeMap<ThreadId, Thread>,
|
||||
idle_thread_id: Option<ThreadId>,
|
||||
current_thread_id: ThreadId,
|
||||
paused_threads: VecDeque<ThreadId>,
|
||||
blocked_threads: BTreeSet<ThreadId>,
|
||||
wakeups: BTreeSet<ThreadId>,
|
||||
}
|
||||
|
||||
impl Scheduler {
|
||||
pub fn new() -> Self {
|
||||
let root_thread = Thread::create_root_thread();
|
||||
let root_id = root_thread.id();
|
||||
let mut threads = BTreeMap::new();
|
||||
threads
|
||||
.insert(root_id, root_thread)
|
||||
.expect_none("map is not empty after creation");
|
||||
Scheduler {
|
||||
threads,
|
||||
current_thread_id: root_id,
|
||||
paused_threads: VecDeque::new(),
|
||||
blocked_threads: BTreeSet::new(),
|
||||
wakeups: BTreeSet::new(),
|
||||
idle_thread_id: None,
|
||||
}
|
||||
}
|
||||
|
||||
fn next_thread(&mut self) -> Option<ThreadId> {
|
||||
self.paused_threads.pop_front()
|
||||
}
|
||||
|
||||
pub fn schedule(&mut self) -> Option<(VirtAddr, ThreadId)> {
|
||||
let mut next_thread_id = self.next_thread();
|
||||
if next_thread_id.is_none() && Some(self.current_thread_id) != self.idle_thread_id {
|
||||
next_thread_id = self.idle_thread_id
|
||||
}
|
||||
if let Some(next_id) = next_thread_id {
|
||||
let next_thread = self
|
||||
.threads
|
||||
.get_mut(&next_id)
|
||||
.expect("next thread does not exist");
|
||||
let next_stack_pointer = next_thread
|
||||
.stack_pointer()
|
||||
.take()
|
||||
.expect("paused thread has no stack pointer");
|
||||
let prev_thread_id = mem::replace(&mut self.current_thread_id, next_thread.id());
|
||||
Some((next_stack_pointer, prev_thread_id))
|
||||
} else {
|
||||
None
|
||||
}
|
||||
}
|
||||
|
||||
pub(super) fn add_paused_thread(
|
||||
&mut self,
|
||||
paused_stack_pointer: VirtAddr,
|
||||
paused_thread_id: ThreadId,
|
||||
switch_reason: SwitchReason,
|
||||
) {
|
||||
let paused_thread = self
|
||||
.threads
|
||||
.get_mut(&paused_thread_id)
|
||||
.expect("paused thread does not exist");
|
||||
paused_thread
|
||||
.stack_pointer()
|
||||
.replace(paused_stack_pointer)
|
||||
.expect_none("running thread should have stack pointer set to None");
|
||||
if Some(paused_thread_id) == self.idle_thread_id {
|
||||
return; // do nothing
|
||||
}
|
||||
match switch_reason {
|
||||
SwitchReason::Paused | SwitchReason::Yield => {
|
||||
self.paused_threads.push_back(paused_thread_id)
|
||||
}
|
||||
SwitchReason::Blocked => {
|
||||
self.blocked_threads.insert(paused_thread_id);
|
||||
self.check_for_wakeup(paused_thread_id);
|
||||
}
|
||||
SwitchReason::Exit => {
|
||||
let thread = self
|
||||
.threads
|
||||
.remove(&paused_thread_id)
|
||||
.expect("thread not found");
|
||||
// TODO: free stack memory again
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
pub fn add_new_thread(&mut self, thread: Thread) {
|
||||
let thread_id = thread.id();
|
||||
self.threads
|
||||
.insert(thread_id, thread)
|
||||
.expect_none("thread already exists");
|
||||
self.paused_threads.push_back(thread_id);
|
||||
}
|
||||
|
||||
pub fn set_idle_thread(&mut self, thread: Thread) {
|
||||
let thread_id = thread.id();
|
||||
self.threads
|
||||
.insert(thread_id, thread)
|
||||
.expect_none("thread already exists");
|
||||
self.idle_thread_id
|
||||
.replace(thread_id)
|
||||
.expect_none("idle thread should be set only once");
|
||||
}
|
||||
|
||||
pub fn current_thread_id(&self) -> ThreadId {
|
||||
self.current_thread_id
|
||||
}
|
||||
|
||||
fn check_for_wakeup(&mut self, thread_id: ThreadId) {
|
||||
if self.wakeups.remove(&thread_id) {
|
||||
assert!(self.blocked_threads.remove(&thread_id));
|
||||
self.paused_threads.push_back(thread_id);
|
||||
}
|
||||
}
|
||||
}
|
||||
@@ -1,82 +0,0 @@
|
||||
use crate::memory::{alloc_stack, StackBounds};
|
||||
use crate::multitasking::context_switch::Stack;
|
||||
use alloc::boxed::Box;
|
||||
use x86_64::{
|
||||
structures::paging::{mapper, FrameAllocator, Mapper, Size4KiB},
|
||||
VirtAddr,
|
||||
};
|
||||
|
||||
#[derive(Debug, Clone, Copy, PartialEq, Eq, PartialOrd, Ord)]
|
||||
pub struct ThreadId(u64);
|
||||
|
||||
impl ThreadId {
|
||||
pub fn as_u64(&self) -> u64 {
|
||||
self.0
|
||||
}
|
||||
|
||||
fn new() -> Self {
|
||||
use core::sync::atomic::{AtomicU64, Ordering};
|
||||
static NEXT_THREAD_ID: AtomicU64 = AtomicU64::new(1);
|
||||
ThreadId(NEXT_THREAD_ID.fetch_add(1, Ordering::SeqCst))
|
||||
}
|
||||
}
|
||||
|
||||
#[derive(Debug)]
|
||||
pub struct Thread {
|
||||
id: ThreadId,
|
||||
stack_pointer: Option<VirtAddr>,
|
||||
stack_bounds: Option<StackBounds>,
|
||||
}
|
||||
|
||||
impl Thread {
|
||||
pub fn create(
|
||||
entry_point: fn() -> !,
|
||||
stack_size: u64,
|
||||
mapper: &mut impl Mapper<Size4KiB>,
|
||||
frame_allocator: &mut impl FrameAllocator<Size4KiB>,
|
||||
) -> Result<Self, mapper::MapToError> {
|
||||
let stack_bounds = alloc_stack(stack_size, mapper, frame_allocator)?;
|
||||
let mut stack = unsafe { Stack::new(stack_bounds.end()) };
|
||||
stack.set_up_for_entry_point(entry_point);
|
||||
Ok(Self::new(stack.get_stack_pointer(), stack_bounds))
|
||||
}
|
||||
|
||||
pub fn create_from_closure<F>(
|
||||
closure: F,
|
||||
stack_size: u64,
|
||||
mapper: &mut impl Mapper<Size4KiB>,
|
||||
frame_allocator: &mut impl FrameAllocator<Size4KiB>,
|
||||
) -> Result<Self, mapper::MapToError>
|
||||
where
|
||||
F: FnOnce() -> ! + 'static + Send + Sync,
|
||||
{
|
||||
let stack_bounds = alloc_stack(stack_size, mapper, frame_allocator)?;
|
||||
let mut stack = unsafe { Stack::new(stack_bounds.end()) };
|
||||
stack.set_up_for_closure(Box::new(closure));
|
||||
Ok(Self::new(stack.get_stack_pointer(), stack_bounds))
|
||||
}
|
||||
|
||||
fn new(stack_pointer: VirtAddr, stack_bounds: StackBounds) -> Self {
|
||||
Thread {
|
||||
id: ThreadId::new(),
|
||||
stack_pointer: Some(stack_pointer),
|
||||
stack_bounds: Some(stack_bounds),
|
||||
}
|
||||
}
|
||||
|
||||
pub(super) fn create_root_thread() -> Self {
|
||||
Thread {
|
||||
id: ThreadId(0),
|
||||
stack_pointer: None,
|
||||
stack_bounds: None,
|
||||
}
|
||||
}
|
||||
|
||||
pub fn id(&self) -> ThreadId {
|
||||
self.id
|
||||
}
|
||||
|
||||
pub(super) fn stack_pointer(&mut self) -> &mut Option<VirtAddr> {
|
||||
&mut self.stack_pointer
|
||||
}
|
||||
}
|
||||
@@ -13,14 +13,10 @@ lazy_static! {
|
||||
#[doc(hidden)]
|
||||
pub fn _print(args: ::core::fmt::Arguments) {
|
||||
use core::fmt::Write;
|
||||
use x86_64::instructions::interrupts;
|
||||
|
||||
interrupts::without_interrupts(|| {
|
||||
SERIAL1
|
||||
.lock()
|
||||
.write_fmt(args)
|
||||
.expect("Printing to serial failed");
|
||||
});
|
||||
SERIAL1
|
||||
.lock()
|
||||
.write_fmt(args)
|
||||
.expect("Printing to serial failed");
|
||||
}
|
||||
|
||||
/// Prints to the host through the serial interface.
|
||||
|
||||
@@ -166,16 +166,11 @@ macro_rules! println {
|
||||
($($arg:tt)*) => ($crate::print!("{}\n", format_args!($($arg)*)));
|
||||
}
|
||||
|
||||
/// Prints the given formatted string to the VGA text buffer
|
||||
/// through the global `WRITER` instance.
|
||||
/// Prints the given formatted string to the VGA text buffer through the global `WRITER` instance.
|
||||
#[doc(hidden)]
|
||||
pub fn _print(args: fmt::Arguments) {
|
||||
use core::fmt::Write;
|
||||
use x86_64::instructions::interrupts;
|
||||
|
||||
interrupts::without_interrupts(|| {
|
||||
WRITER.lock().write_fmt(args).unwrap();
|
||||
});
|
||||
WRITER.lock().write_fmt(args).unwrap();
|
||||
}
|
||||
|
||||
#[test_case]
|
||||
@@ -196,20 +191,14 @@ fn test_println_many() {
|
||||
|
||||
#[test_case]
|
||||
fn test_println_output() {
|
||||
use core::fmt::Write;
|
||||
use x86_64::instructions::interrupts;
|
||||
|
||||
serial_print!("test_println_output... ");
|
||||
|
||||
let s = "Some test string that fits on a single line";
|
||||
interrupts::without_interrupts(|| {
|
||||
let mut writer = WRITER.lock();
|
||||
writeln!(writer, "\n{}", s).expect("writeln failed");
|
||||
for (i, c) in s.chars().enumerate() {
|
||||
let screen_char = writer.buffer.chars[BUFFER_HEIGHT - 2][i].read();
|
||||
assert_eq!(char::from(screen_char.ascii_character), c);
|
||||
}
|
||||
});
|
||||
println!("{}", s);
|
||||
for (i, c) in s.chars().enumerate() {
|
||||
let screen_char = WRITER.lock().buffer.chars[BUFFER_HEIGHT - 2][i].read();
|
||||
assert_eq!(char::from(screen_char.ascii_character), c);
|
||||
}
|
||||
|
||||
serial_println!("[ok]");
|
||||
}
|
||||
|
||||
@@ -1,76 +0,0 @@
|
||||
#![no_std]
|
||||
#![no_main]
|
||||
#![feature(custom_test_frameworks)]
|
||||
#![test_runner(blog_os::test_runner)]
|
||||
#![reexport_test_harness_main = "test_main"]
|
||||
|
||||
extern crate alloc;
|
||||
|
||||
use alloc::{boxed::Box, vec::Vec};
|
||||
use blog_os::{allocator::HEAP_SIZE, serial_print, serial_println};
|
||||
use bootloader::{entry_point, BootInfo};
|
||||
use core::panic::PanicInfo;
|
||||
|
||||
entry_point!(main);
|
||||
|
||||
fn main(boot_info: &'static BootInfo) -> ! {
|
||||
use blog_os::allocator;
|
||||
use blog_os::memory::{self, BootInfoFrameAllocator};
|
||||
use x86_64::VirtAddr;
|
||||
|
||||
blog_os::init();
|
||||
let phys_mem_offset = VirtAddr::new(boot_info.physical_memory_offset);
|
||||
let mut mapper = unsafe { memory::init(phys_mem_offset) };
|
||||
let mut frame_allocator = unsafe { BootInfoFrameAllocator::init(&boot_info.memory_map) };
|
||||
allocator::init_heap(&mut mapper, &mut frame_allocator).expect("heap initialization failed");
|
||||
|
||||
test_main();
|
||||
loop {}
|
||||
}
|
||||
|
||||
#[test_case]
|
||||
fn simple_allocation() {
|
||||
serial_print!("simple_allocation... ");
|
||||
let heap_value = Box::new(41);
|
||||
assert_eq!(*heap_value, 41);
|
||||
serial_println!("[ok]");
|
||||
}
|
||||
|
||||
#[test_case]
|
||||
fn large_vec() {
|
||||
serial_print!("large_vec... ");
|
||||
let n = 1000;
|
||||
let mut vec = Vec::new();
|
||||
for i in 0..n {
|
||||
vec.push(i);
|
||||
}
|
||||
assert_eq!(vec.iter().sum::<u64>(), (n - 1) * n / 2);
|
||||
serial_println!("[ok]");
|
||||
}
|
||||
|
||||
#[test_case]
|
||||
fn many_boxes() {
|
||||
serial_print!("many_boxes... ");
|
||||
for i in 0..HEAP_SIZE {
|
||||
let x = Box::new(i);
|
||||
assert_eq!(*x, i);
|
||||
}
|
||||
serial_println!("[ok]");
|
||||
}
|
||||
|
||||
#[test_case]
|
||||
fn many_boxes_long_lived() {
|
||||
serial_print!("many_boxes_long_lived... ");
|
||||
let long_lived = Box::new(1); // new
|
||||
for i in 0..HEAP_SIZE {
|
||||
let x = Box::new(i);
|
||||
assert_eq!(*x, i);
|
||||
}
|
||||
assert_eq!(*long_lived, 1); // new
|
||||
serial_println!("[ok]");
|
||||
}
|
||||
|
||||
#[panic_handler]
|
||||
fn panic(info: &PanicInfo) -> ! {
|
||||
blog_os::test_panic_handler(info)
|
||||
}
|
||||
Reference in New Issue
Block a user