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12 Commits

Author SHA1 Message Date
Philipp Oppermann
b44d8ab7fc Merge pull request #1412 from tigeryant/post-01
Added [[bin]] section to Cargo.toml
2025-05-09 15:46:51 +02:00
John Davies
c551fec1ce Added [[bin]] section to Cargo.toml with test and bench set to false to prevent duplicate definition of lang item 2025-05-02 00:35:50 +07:00
Philipp Oppermann
430e2143f8 Fix: no_mangle is an unsafe attribute since Rust 2024 2025-03-27 15:06:17 +01:00
Philipp Oppermann
86ffa24e8e Update to Rust 2024 edition 2025-03-27 15:05:58 +01:00
Philipp Oppermann
8708b54756 Readme: Update workflow name in badge 2021-05-21 19:53:01 +02:00
Philipp Oppermann
bdb6a424a8 CI: Rename 'Build Code' workflow to 'Code' 2021-03-10 09:22:57 +01:00
Philipp Oppermann
1501669819 Update lockfile format 2021-03-10 09:15:54 +01:00
Philipp Oppermann
deb0f63dff Ci: Don't fail fast 2021-03-10 09:13:00 +01:00
Philipp Oppermann
6ad573bb11 Run workflow on workflow_dispatch event
This allows us to trigger a branch build from the master branch on schedule.
2020-08-16 18:01:58 +02:00
Philipp Oppermann
3fb4695f6c Bootimage is not needed for post-01 2020-07-17 11:39:47 +02:00
Philipp Oppermann
635677d07c Fix workflow syntax 2020-07-17 11:38:30 +02:00
Philipp Oppermann
b276ec4765 Update CI script to be consistent with other branches 2020-07-17 11:36:33 +02:00
29 changed files with 132 additions and 1979 deletions

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@@ -1,5 +0,0 @@
[build]
target = "x86_64-blog_os.json"
[target.'cfg(target_os = "none")']
runner = "bootimage runner"

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@@ -1,96 +0,0 @@
name: Build Code
on:
push:
branches:
- '*'
- '!staging.tmp'
tags:
- '*'
schedule:
- cron: '40 3 * * *' # every day at 3:40
pull_request:
jobs:
test:
name: "Test"
strategy:
matrix:
platform: [
ubuntu-latest,
macos-latest,
windows-latest
]
runs-on: ${{ matrix.platform }}
timeout-minutes: 15
steps:
- name: "Checkout Repository"
uses: actions/checkout@v1
- name: Install Rustup
run: |
curl --proto '=https' --tlsv1.2 -sSf https://sh.rustup.rs | sh -s -- -y --default-toolchain nightly
echo ::add-path::$HOME/.cargo/bin
if: runner.os == 'macOS'
- name: "Print Rust Version"
run: |
rustc -Vv
cargo -Vv
- name: "Install Rustup Components"
run: rustup component add rust-src llvm-tools-preview
- name: "Install cargo-xbuild"
run: cargo install cargo-xbuild --debug
- name: "Install bootimage"
run: cargo install bootimage --debug
- name: "Run cargo xbuild"
run: cargo xbuild
- name: "Create Bootimage"
run: cargo bootimage
# install QEMU
- name: Install QEMU (Linux)
run: sudo apt update && sudo apt install qemu-system-x86
if: runner.os == 'Linux'
- name: Install QEMU (macOS)
run: brew install qemu
if: runner.os == 'macOS'
env:
HOMEBREW_NO_AUTO_UPDATE: 1
HOMEBREW_NO_BOTTLE_SOURCE_FALLBACK: 1
HOMEBREW_NO_INSTALL_CLEANUP: 1
- name: Install Scoop (Windows)
run: |
Invoke-Expression (New-Object System.Net.WebClient).DownloadString('https://get.scoop.sh')
echo ::add-path::$HOME\scoop\shims
if: runner.os == 'Windows'
shell: pwsh
- name: Install QEMU (Windows)
run: scoop install qemu
if: runner.os == 'Windows'
shell: pwsh
- name: "Print QEMU Version"
run: qemu-system-x86_64 --version
- name: "Run cargo xtest"
run: cargo xtest
check_formatting:
name: "Check Formatting"
runs-on: ubuntu-latest
timeout-minutes: 2
steps:
- uses: actions/checkout@v1
- name: "Use the latest Rust nightly with rustfmt"
uses: actions-rs/toolchain@v1
with:
toolchain: nightly
profile: minimal
components: rustfmt
override: true
- run: cargo fmt -- --check

110
.github/workflows/code.yml vendored Normal file
View File

@@ -0,0 +1,110 @@
name: Code
on:
push:
branches:
- '*'
- '!staging.tmp'
tags:
- '*'
schedule:
- cron: '40 3 * * *' # every day at 3:40
pull_request:
workflow_dispatch:
jobs:
check:
name: Check
strategy:
fail-fast: false
matrix:
platform: [
ubuntu-latest,
macos-latest,
windows-latest
]
runs-on: ${{ matrix.platform }}
steps:
- name: Checkout Repository
uses: actions/checkout@v2
- name: Install Rust Toolchain
uses: actions-rs/toolchain@v1
with:
profile: minimal
toolchain: nightly
- name: Install `rust-src` Rustup Component
run: rustup component add rust-src
- name: Run `cargo check`
uses: actions-rs/cargo@v1
with:
command: check
test:
name: Test
strategy:
fail-fast: false
matrix:
platform: [
ubuntu-latest,
macos-latest,
windows-latest
]
runs-on: ${{ matrix.platform }}
steps:
- name: Install Rust Toolchain
uses: actions-rs/toolchain@v1
with:
profile: minimal
toolchain: nightly
- name: Checkout Repository
uses: actions/checkout@v2
- name: Add thumbv7em-none-eabihf Target
run: rustup target add thumbv7em-none-eabihf
- name: Build for thumbv7em-none-eabihf
run: cargo build --target thumbv7em-none-eabihf
- name: Build for Linux
if: runner.os == 'Linux'
run: cargo rustc -- -C link-arg=-nostartfiles
- name: Build for macOS
if: runner.os == 'macOS'
run: cargo rustc -- -C link-args="-e __start -static -nostartfiles"
- name: Build for Windows
if: runner.os == 'Windows'
run: cargo rustc -- -C link-args="/ENTRY:_start /SUBSYSTEM:console"
check_formatting:
name: Check Formatting
runs-on: ubuntu-latest
steps:
- name: Checkout Repository
uses: actions/checkout@v2
- name: Install Rust Toolchain
uses: actions-rs/toolchain@v1
with:
profile: minimal
toolchain: nightly
components: rustfmt
override: true
- name: Run `cargo fmt`
uses: actions-rs/cargo@v1
with:
command: fmt
args: --all -- --check
clippy:
name: Clippy
runs-on: ubuntu-latest
steps:
- name: Checkout Repository
uses: actions/checkout@v2
- name: Install Rust Toolchain
uses: actions-rs/toolchain@v1
with:
profile: minimal
toolchain: nightly
components: clippy, rust-src
override: true
- name: Run `cargo clippy`
uses: actions-rs/cargo@v1
with:
command: clippy

203
Cargo.lock generated
View File

@@ -1,208 +1,7 @@
# This file is automatically @generated by Cargo.
# It is not intended for manual editing.
[[package]]
name = "autocfg"
version = "1.0.0"
source = "registry+https://github.com/rust-lang/crates.io-index"
checksum = "f8aac770f1885fd7e387acedd76065302551364496e46b3dd00860b2f8359b9d"
[[package]]
name = "bit_field"
version = "0.9.0"
source = "registry+https://github.com/rust-lang/crates.io-index"
checksum = "ed8765909f9009617974ab6b7d332625b320b33c326b1e9321382ef1999b5d56"
[[package]]
name = "bitflags"
version = "1.2.1"
source = "registry+https://github.com/rust-lang/crates.io-index"
checksum = "cf1de2fe8c75bc145a2f577add951f8134889b4795d47466a54a5c846d691693"
version = 3
[[package]]
name = "blog_os"
version = "0.1.0"
dependencies = [
"bootloader",
"conquer-once",
"crossbeam-queue",
"futures-util",
"lazy_static",
"linked_list_allocator",
"pc-keyboard",
"pic8259_simple",
"spin",
"uart_16550",
"volatile",
"x86_64",
]
[[package]]
name = "bootloader"
version = "0.8.8"
source = "registry+https://github.com/rust-lang/crates.io-index"
checksum = "c3ed4f735c4e455ba86a3d2939b1c0729414153642106c9d035693355630a42c"
[[package]]
name = "cfg-if"
version = "0.1.10"
source = "registry+https://github.com/rust-lang/crates.io-index"
checksum = "4785bdd1c96b2a846b2bd7cc02e86b6b3dbf14e7e53446c4f54c92a361040822"
[[package]]
name = "conquer-once"
version = "0.2.0"
source = "registry+https://github.com/rust-lang/crates.io-index"
checksum = "6f7644600a548ecad74e4a918392af1798f7dd045be610be3203b9e129b4f98f"
dependencies = [
"conquer-util",
]
[[package]]
name = "conquer-util"
version = "0.2.0"
source = "registry+https://github.com/rust-lang/crates.io-index"
checksum = "654fb2472cc369d311c547103a1fa81d467bef370ae7a0680f65939895b1182a"
[[package]]
name = "cpuio"
version = "0.2.0"
source = "registry+https://github.com/rust-lang/crates.io-index"
checksum = "22b8e308ccfc5acf3b82f79c0eac444cf6114cb2ac67a230ca6c177210068daa"
[[package]]
name = "crossbeam-queue"
version = "0.2.1"
source = "registry+https://github.com/rust-lang/crates.io-index"
checksum = "c695eeca1e7173472a32221542ae469b3e9aac3a4fc81f7696bcad82029493db"
dependencies = [
"cfg-if",
"crossbeam-utils",
]
[[package]]
name = "crossbeam-utils"
version = "0.7.2"
source = "registry+https://github.com/rust-lang/crates.io-index"
checksum = "c3c7c73a2d1e9fc0886a08b93e98eb643461230d5f1925e4036204d5f2e261a8"
dependencies = [
"autocfg",
"cfg-if",
]
[[package]]
name = "futures-core"
version = "0.3.4"
source = "registry+https://github.com/rust-lang/crates.io-index"
checksum = "f25592f769825e89b92358db00d26f965761e094951ac44d3663ef25b7ac464a"
[[package]]
name = "futures-task"
version = "0.3.4"
source = "registry+https://github.com/rust-lang/crates.io-index"
checksum = "7b0a34e53cf6cdcd0178aa573aed466b646eb3db769570841fda0c7ede375a27"
[[package]]
name = "futures-util"
version = "0.3.4"
source = "registry+https://github.com/rust-lang/crates.io-index"
checksum = "22766cf25d64306bedf0384da004d05c9974ab104fcc4528f1236181c18004c5"
dependencies = [
"futures-core",
"futures-task",
"pin-utils",
]
[[package]]
name = "lazy_static"
version = "1.4.0"
source = "registry+https://github.com/rust-lang/crates.io-index"
checksum = "e2abad23fbc42b3700f2f279844dc832adb2b2eb069b2df918f455c4e18cc646"
dependencies = [
"spin",
]
[[package]]
name = "linked_list_allocator"
version = "0.8.0"
source = "registry+https://github.com/rust-lang/crates.io-index"
checksum = "18c618c431dfe4419afbe22852f6aceffbc17bd82ba0a18b982def291000824c"
dependencies = [
"spinning_top",
]
[[package]]
name = "lock_api"
version = "0.3.3"
source = "registry+https://github.com/rust-lang/crates.io-index"
checksum = "79b2de95ecb4691949fea4716ca53cdbcfccb2c612e19644a8bad05edcf9f47b"
dependencies = [
"scopeguard",
]
[[package]]
name = "pc-keyboard"
version = "0.5.0"
source = "registry+https://github.com/rust-lang/crates.io-index"
checksum = "c48392db76c4e9a69e0b3be356c5f97ebb7b14413c5e4fd0af4755dbf86e2fce"
[[package]]
name = "pic8259_simple"
version = "0.1.1"
source = "registry+https://github.com/rust-lang/crates.io-index"
checksum = "dc64b2fd10828da8521b6cdabe0679385d7d2a3a6d4c336b819d1fa31ba35c72"
dependencies = [
"cpuio",
]
[[package]]
name = "pin-utils"
version = "0.1.0-alpha.4"
source = "registry+https://github.com/rust-lang/crates.io-index"
checksum = "5894c618ce612a3fa23881b152b608bafb8c56cfc22f434a3ba3120b40f7b587"
[[package]]
name = "scopeguard"
version = "1.1.0"
source = "registry+https://github.com/rust-lang/crates.io-index"
checksum = "d29ab0c6d3fc0ee92fe66e2d99f700eab17a8d57d1c1d3b748380fb20baa78cd"
[[package]]
name = "spin"
version = "0.5.2"
source = "registry+https://github.com/rust-lang/crates.io-index"
checksum = "6e63cff320ae2c57904679ba7cb63280a3dc4613885beafb148ee7bf9aa9042d"
[[package]]
name = "spinning_top"
version = "0.1.0"
source = "registry+https://github.com/rust-lang/crates.io-index"
checksum = "32d801a3a53bcf5071f85fef8d5cab9e5f638fc5580a37e6eb7aba4b37438d24"
dependencies = [
"lock_api",
]
[[package]]
name = "uart_16550"
version = "0.2.4"
source = "registry+https://github.com/rust-lang/crates.io-index"
checksum = "d44b0f30cb82b0fbc15b78ade1064226529ad52028bc8cb8accb98ff6f3d7131"
dependencies = [
"bitflags",
"x86_64",
]
[[package]]
name = "volatile"
version = "0.2.6"
source = "registry+https://github.com/rust-lang/crates.io-index"
checksum = "6af0edf5b4faacc31fc51159244d78d65ec580f021afcef7bd53c04aeabc7f29"
[[package]]
name = "x86_64"
version = "0.9.6"
source = "registry+https://github.com/rust-lang/crates.io-index"
checksum = "4206b60c9f99766329b66962aa8ddc01df6c7edd02edc046b7a69d5df9fcdbcf"
dependencies = [
"bit_field",
"bitflags",
]

View File

@@ -2,47 +2,17 @@
name = "blog_os"
version = "0.1.0"
authors = ["Philipp Oppermann <dev@phil-opp.com>"]
edition = "2018"
[[test]]
name = "should_panic"
harness = false
[[test]]
name = "stack_overflow"
harness = false
edition = "2024"
[dependencies]
bootloader = { version = "0.8.0", features = ["map_physical_memory"]}
volatile = "0.2.6"
spin = "0.5.2"
x86_64 = "0.9.6"
uart_16550 = "0.2.0"
pic8259_simple = "0.1.1"
pc-keyboard = "0.5.0"
linked_list_allocator = "0.8.0"
[dependencies.lazy_static]
version = "1.0"
features = ["spin_no_std"]
[profile.dev]
panic = "abort"
[dependencies.crossbeam-queue]
version = "0.2.1"
default-features = false
features = ["alloc"]
[profile.release]
panic = "abort"
[dependencies.futures-util]
version = "0.3.4"
default-features = false
features = ["alloc", "async-await"]
[dependencies.conquer-once]
version = "0.2.0"
default-features = false
[package.metadata.bootimage]
test-args = [
"-device", "isa-debug-exit,iobase=0xf4,iosize=0x04", "-serial", "stdio",
"-display", "none"
]
test-success-exit-code = 33 # (0x10 << 1) | 1
[[bin]]
name = "blog_os"
test = false
bench = false

View File

@@ -1,61 +1,25 @@
# Blog OS (Heap Allocation)
# Blog OS (A Freestanding Rust Binary)
[![Build Status](https://github.com/phil-opp/blog_os/workflows/Build%20Code/badge.svg?branch=post-10)](https://github.com/phil-opp/blog_os/actions?query=workflow%3A%22Build+Code%22+branch%3Apost-10)
[![Build Status](https://github.com/phil-opp/blog_os/workflows/Code/badge.svg?branch=post-01)](https://github.com/phil-opp/blog_os/actions?query=workflow%3A%22Code%22+branch%3Apost-01)
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 [A Freestanding Rust Binary][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/freestanding-rust-binary/
**Check out the [master branch](https://github.com/phil-opp/blog_os) for more information.**
## Building
You need a nightly Rust compiler. First you need to install the `cargo-xbuild` and `bootimage` tools:
To build the project on Linux, run:
```
cargo install cargo-xbuild bootimage
cargo rustc -- -Clink-arg=-nostartfiles
```
Then you can build the project by running:
```
cargo xbuild
```
To create a bootable disk image, run:
```
cargo bootimage
```
This creates a bootable disk image in the `target/x86_64-blog_os/debug` directory.
The entry point and the build command differ slightly on macOS and Windows. See the [post] for more information.
Please file an issue if you have any problems.
## Running
You can run the disk image in [QEMU] through:
[QEMU]: https://www.qemu.org/
```
cargo xrun
```
Of course [QEMU] needs to be installed for this.
You can also write the image to an USB stick for booting it on a real machine. On Linux, the command for this is:
```
dd if=target/x86_64-blog_os/debug/bootimage-blog_os.bin of=/dev/sdX && sync
```
Where `sdX` is the device name of your USB stick. **Be careful** to choose the correct device name, because everything on that device is overwritten.
## Testing
To run the unit and integration tests, execute `cargo xtest`.
## License
Licensed under either of

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@@ -1 +0,0 @@
nightly

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@@ -1,82 +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<Size4KiB>> {
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()
}
}
/// Align the given address `addr` upwards to alignment `align`.
///
/// Requires that `align` is a power of two.
fn align_up(addr: usize, align: usize) -> usize {
(addr + align - 1) & !(align - 1)
}

View File

@@ -1,61 +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.saturating_add(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 = match alloc_start.checked_add(layout.size()) {
Some(end) => end,
None => return ptr::null_mut(),
};
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;
}
}
}

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@@ -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);
}
}
}
}

View File

@@ -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(&region, 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.checked_add(size).ok_or(())?;
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.lock();
if let Some((region, alloc_start)) = allocator.find_region(size, align) {
let alloc_end = alloc_start.checked_add(size).expect("overflow");
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.lock().add_free_region(ptr as usize, size)
}
}

View File

@@ -1,75 +0,0 @@
use crate::{print, println, task::interrupt_wake};
use conquer_once::spin::OnceCell;
use core::future::Future;
use core::{
pin::Pin,
task::{Context, Poll},
};
use crossbeam_queue::ArrayQueue;
use futures_util::task::AtomicWaker;
use pc_keyboard::{layouts, DecodedKey, HandleControl, Keyboard, ScancodeSet1};
static WAKER: AtomicWaker = AtomicWaker::new();
static SCANCODE_QUEUE: OnceCell<ArrayQueue<u8>> = OnceCell::uninit();
pub fn init() {
SCANCODE_QUEUE
.try_init_once(|| ArrayQueue::new(10))
.expect("failed to init scancode queue");
}
/// Called by the keyboard interrupt handler
///
/// Must not block (including spinlocks).
pub(crate) fn keyboard_scancode(scancode: u8) {
let scancode_queue = SCANCODE_QUEUE
.try_get()
.expect("scancode queue not initialized");
if let Err(_) = scancode_queue.push(scancode) {
println!("WARNING: dropping keyboard input");
}
if let Some(waker) = WAKER.take() {
interrupt_wake(waker);
}
}
fn next_scancode() -> impl Future<Output = u8> {
NextScancode
}
struct NextScancode;
impl Future for NextScancode {
type Output = u8;
fn poll(self: Pin<&mut Self>, cx: &mut Context) -> Poll<u8> {
let scancodes = SCANCODE_QUEUE
.try_get()
.expect("scancode queue not initialized");
// fast path
if let Ok(scancode) = scancodes.pop() {
return Poll::Ready(scancode);
}
WAKER.register(&cx.waker());
match scancodes.pop() {
Ok(scancode) => Poll::Ready(scancode),
Err(crossbeam_queue::PopError) => Poll::Pending,
}
}
}
pub async fn keyboard_task() {
let mut keyboard = Keyboard::new(layouts::Us104Key, ScancodeSet1, HandleControl::Ignore);
loop {
if let Ok(Some(key_event)) = keyboard.add_byte(next_scancode().await) {
if let Some(key) = keyboard.process_keyevent(key_event) {
match key {
DecodedKey::Unicode(character) => print!("{}", character),
DecodedKey::RawKey(key) => print!("{:?}", key),
}
}
}
}
}

View File

@@ -1,6 +0,0 @@
pub mod keyboard;
pub mod timer;
pub fn init() {
keyboard::init();
}

View File

@@ -1,55 +0,0 @@
use crate::{print, task::interrupt_wake};
use core::future::Future;
use core::{
pin::Pin,
sync::atomic::{AtomicU64, Ordering},
task::{Context, Poll},
};
use futures_util::task::AtomicWaker;
static TICKS: AtomicU64 = AtomicU64::new(0);
static WAKER: AtomicWaker = AtomicWaker::new();
/// Called by the timer interrupt handler
///
/// Must not block (including spinlocks).
pub(crate) fn tick() {
TICKS.fetch_add(1, Ordering::Release);
if let Some(waker) = WAKER.take() {
interrupt_wake(waker);
}
}
fn next_tick() -> impl Future<Output = u64> {
static NEXT_TICK: AtomicU64 = AtomicU64::new(1);
NextTick {
ticks: NEXT_TICK.fetch_add(1, Ordering::Release),
}
}
struct NextTick {
ticks: u64,
}
impl Future for NextTick {
type Output = u64;
fn poll(mut self: Pin<&mut Self>, cx: &mut Context) -> Poll<u64> {
WAKER.register(&cx.waker());
let current_ticks = TICKS.load(Ordering::Acquire);
if self.ticks < current_ticks {
self.ticks += 1;
Poll::Ready(self.ticks)
} else {
Poll::Pending
}
}
}
pub async fn timer_task() {
loop {
next_tick().await;
print!(".");
}
}

View File

@@ -1,52 +0,0 @@
use lazy_static::lazy_static;
use x86_64::structures::gdt::{Descriptor, GlobalDescriptorTable, SegmentSelector};
use x86_64::structures::tss::TaskStateSegment;
use x86_64::VirtAddr;
pub const DOUBLE_FAULT_IST_INDEX: u16 = 0;
lazy_static! {
static ref TSS: TaskStateSegment = {
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];
let stack_start = VirtAddr::from_ptr(unsafe { &STACK });
let stack_end = stack_start + STACK_SIZE;
stack_end
};
tss
};
}
lazy_static! {
static ref GDT: (GlobalDescriptorTable, Selectors) = {
let mut gdt = GlobalDescriptorTable::new();
let code_selector = gdt.add_entry(Descriptor::kernel_code_segment());
let tss_selector = gdt.add_entry(Descriptor::tss_segment(&TSS));
(
gdt,
Selectors {
code_selector,
tss_selector,
},
)
};
}
struct Selectors {
code_selector: SegmentSelector,
tss_selector: SegmentSelector,
}
pub fn init() {
use x86_64::instructions::segmentation::set_cs;
use x86_64::instructions::tables::load_tss;
GDT.0.load();
unsafe {
set_cs(GDT.1.code_selector);
load_tss(GDT.1.tss_selector);
}
}

View File

@@ -1,105 +0,0 @@
use crate::{gdt, hlt_loop, 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) });
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
};
}
pub fn init_idt() {
IDT.load();
}
extern "x86-interrupt" fn breakpoint_handler(stack_frame: &mut InterruptStackFrame) {
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,
) -> ! {
panic!("EXCEPTION: DOUBLE FAULT\n{:#?}", stack_frame);
}
extern "x86-interrupt" fn timer_interrupt_handler(_stack_frame: &mut InterruptStackFrame) {
crate::driver::timer::tick();
unsafe {
PICS.lock()
.notify_end_of_interrupt(InterruptIndex::Timer.as_u8());
}
}
extern "x86-interrupt" fn keyboard_interrupt_handler(_stack_frame: &mut InterruptStackFrame) {
use x86_64::instructions::port::Port;
let mut port = Port::new(0x60);
let scancode: u8 = unsafe { port.read() };
crate::driver::keyboard::keyboard_scancode(scancode);
unsafe {
PICS.lock()
.notify_end_of_interrupt(InterruptIndex::Keyboard.as_u8());
}
}
#[cfg(test)]
use crate::{serial_print, serial_println};
#[test_case]
fn test_breakpoint_exception() {
serial_print!("test_breakpoint_exception...");
// invoke a breakpoint exception
x86_64::instructions::interrupts::int3();
serial_println!("[ok]");
}

View File

@@ -1,99 +0,0 @@
#![no_std]
#![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(wake_trait)]
#![feature(const_in_array_repeat_expressions)]
#![feature(type_alias_impl_trait)]
#![feature(asm)]
#![test_runner(crate::test_runner)]
#![reexport_test_harness_main = "test_main"]
extern crate alloc;
use core::panic::PanicInfo;
pub mod allocator;
pub mod driver;
pub mod gdt;
pub mod interrupts;
pub mod memory;
pub mod serial;
pub mod task;
pub mod vga_buffer;
pub fn init() {
gdt::init();
interrupts::init_idt();
unsafe { interrupts::PICS.lock().initialize() };
}
pub fn init_heap_structures() {
task::init();
driver::init();
}
pub fn test_runner(tests: &[&dyn Fn()]) {
serial_println!("Running {} tests", tests.len());
for test in tests {
test();
}
exit_qemu(QemuExitCode::Success);
}
pub fn test_panic_handler(info: &PanicInfo) -> ! {
serial_println!("[failed]\n");
serial_println!("Error: {}\n", info);
exit_qemu(QemuExitCode::Failed);
hlt_loop();
}
#[derive(Debug, Clone, Copy, PartialEq, Eq)]
#[repr(u32)]
pub enum QemuExitCode {
Success = 0x10,
Failed = 0x11,
}
pub fn exit_qemu(exit_code: QemuExitCode) {
use x86_64::instructions::port::Port;
unsafe {
let mut port = Port::new(0xf4);
port.write(exit_code as u32);
}
}
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) -> ! {
init();
test_main();
hlt_loop();
}
#[cfg(test)]
#[panic_handler]
fn panic(info: &PanicInfo) -> ! {
test_panic_handler(info)
}
#[alloc_error_handler]
fn alloc_error_handler(layout: alloc::alloc::Layout) -> ! {
panic!("allocation error: {:?}", layout)
}

View File

@@ -1,99 +1,15 @@
#![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, rc::Rc, vec, vec::Vec};
use blog_os::println;
use bootloader::{entry_point, BootInfo};
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;
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");
blog_os::init_heap_structures();
// 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);
}
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)
);
use blog_os::task::executor::Executor;
let mut executor = Executor::new();
executor.spawn(bar());
executor.spawn(async {
#[cfg(test)]
test_main();
});
executor.spawn(async {
println!("It did not crash!");
});
executor.spawn(blog_os::driver::timer::timer_task());
executor.spawn(blog_os::driver::keyboard::keyboard_task());
executor.run();
#[unsafe(no_mangle)]
pub extern "C" fn _start() -> ! {
loop {}
}
/// This function is called on panic.
#[cfg(not(test))]
#[panic_handler]
fn panic(info: &PanicInfo) -> ! {
println!("{}", info);
blog_os::hlt_loop();
}
#[cfg(test)]
#[panic_handler]
fn panic(info: &PanicInfo) -> ! {
blog_os::test_panic_handler(info)
}
async fn test() -> u32 {
42
}
async fn foo() -> u32 {
test().await * 2
}
async fn bar() {
println!("foo result: {}", foo().await);
fn panic(_info: &PanicInfo) -> ! {
loop {}
}

View File

@@ -1,106 +0,0 @@
use bootloader::bootinfo::{MemoryMap, MemoryRegionType};
use x86_64::{
structures::paging::{
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
}
/// 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
}
}

View File

@@ -1,41 +0,0 @@
use lazy_static::lazy_static;
use spin::Mutex;
use uart_16550::SerialPort;
lazy_static! {
pub static ref SERIAL1: Mutex<SerialPort> = {
let mut serial_port = unsafe { SerialPort::new(0x3F8) };
serial_port.init();
Mutex::new(serial_port)
};
}
#[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");
});
}
/// Prints to the host through the serial interface.
#[macro_export]
macro_rules! serial_print {
($($arg:tt)*) => {
$crate::serial::_print(format_args!($($arg)*));
};
}
/// Prints to the host through the serial interface, appending a newline.
#[macro_export]
macro_rules! serial_println {
() => ($crate::serial_print!("\n"));
($fmt:expr) => ($crate::serial_print!(concat!($fmt, "\n")));
($fmt:expr, $($arg:tt)*) => ($crate::serial_print!(
concat!($fmt, "\n"), $($arg)*));
}

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@@ -1,127 +0,0 @@
use super::interrupt_wakeups::interrupt_wakeups;
use crate::println;
use alloc::{
boxed::Box,
collections::{BTreeMap, VecDeque},
sync::Arc,
task::Wake,
};
use core::{
future::Future,
pin::Pin,
task::{Context, Poll},
};
use crossbeam_queue::SegQueue;
pub type Task = Pin<Box<dyn Future<Output = ()>>>;
type TaskId = usize;
pub struct Executor {
task_queue: VecDeque<Task>,
wake_queue: Arc<SegQueue<TaskId>>,
pending_tasks: BTreeMap<TaskId, Task>,
}
impl Executor {
pub fn new() -> Self {
Executor {
task_queue: VecDeque::new(),
wake_queue: Arc::new(SegQueue::new()),
pending_tasks: BTreeMap::new(),
}
}
pub fn spawn(&mut self, task: impl Future<Output = ()> + 'static) {
self.task_queue.push_back(Box::pin(task))
}
pub fn run(&mut self) -> ! {
loop {
self.run_ready_tasks();
self.apply_interrupt_wakeups();
self.wake_waiting_tasks();
self.hlt_if_idle();
}
}
fn run_ready_tasks(&mut self) {
while let Some(mut task) = self.task_queue.pop_front() {
let waker = self.create_waker(&task).into();
let mut context = Context::from_waker(&waker);
match task.as_mut().poll(&mut context) {
Poll::Ready(()) => {} // task done
Poll::Pending => {
// add task to pending_tasks and wait for wakeup
let task_id = Self::task_id(&task);
if self.pending_tasks.insert(task_id, task).is_some() {
panic!("Task with same ID already in pending_tasks");
}
}
}
}
}
/// Invoke wakers for tasks woken by interrupts
///
/// The interrupt handlers can't invoke the waker directly since wakers
/// might execute arbitrary code, e.g. allocate, which should not be done
/// in interrupt handlers to avoid deadlocks.
fn apply_interrupt_wakeups(&mut self) {
while let Ok(waker) = interrupt_wakeups().pop() {
waker.wake();
}
}
fn wake_waiting_tasks(&mut self) {
while let Ok(task_id) = self.wake_queue.pop() {
if let Some(task) = self.pending_tasks.remove(&task_id) {
self.task_queue.push_back(task);
} else {
println!("WARNING: woken task not found in pending_tasks");
}
}
}
/// Executes the `hlt` instruction if there are no ready tasks
fn hlt_if_idle(&self) {
if self.task_queue.is_empty() {
// disable interrupts to avoid races
x86_64::instructions::interrupts::disable();
// check if relevant interrupts occured since the last check
if interrupt_wakeups().is_empty() {
// no interrupts occured -> hlt to wait for next interrupt
x86_64::instructions::interrupts::enable_interrupts_and_hlt();
} else {
// there were some new wakeups -> continue execution
x86_64::instructions::interrupts::enable();
}
}
}
fn task_id(task: &Task) -> TaskId {
let future_ref: &dyn Future<Output = ()> = &**task;
future_ref as *const _ as *const () as usize
}
fn create_waker(&self, task: &Task) -> Arc<Waker> {
Arc::new(Waker {
wake_queue: self.wake_queue.clone(),
task_id: Self::task_id(task),
})
}
}
pub struct Waker {
wake_queue: Arc<SegQueue<TaskId>>,
task_id: TaskId,
}
impl Wake for Waker {
fn wake(self: Arc<Self>) {
self.wake_by_ref();
}
fn wake_by_ref(self: &Arc<Self>) {
self.wake_queue.push(self.task_id);
}
}

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@@ -1,25 +0,0 @@
use crate::println;
use conquer_once::spin::OnceCell;
use core::task::Waker;
use crossbeam_queue::ArrayQueue;
static INTERRUPT_WAKEUPS: OnceCell<ArrayQueue<Waker>> = OnceCell::uninit();
pub fn init() {
INTERRUPT_WAKEUPS
.try_init_once(|| ArrayQueue::new(10))
.expect("failed to init interrupt wakeup queue");
}
/// Queues a waker for waking in an interrupt-safe way
pub(crate) fn interrupt_wake(waker: Waker) {
if let Err(_) = interrupt_wakeups().push(waker) {
println!("WARNING: dropping interrupt wakeup");
}
}
pub(super) fn interrupt_wakeups() -> &'static ArrayQueue<Waker> {
INTERRUPT_WAKEUPS
.try_get()
.expect("interrupt wakeup queue not initialized")
}

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@@ -1,8 +0,0 @@
pub(crate) use interrupt_wakeups::interrupt_wake;
pub mod executor;
mod interrupt_wakeups;
pub fn init() {
interrupt_wakeups::init();
}

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@@ -1,215 +0,0 @@
use core::fmt;
use lazy_static::lazy_static;
use spin::Mutex;
use volatile::Volatile;
#[cfg(test)]
use crate::{serial_print, serial_println};
lazy_static! {
/// A global `Writer` instance that can be used for printing to the VGA text buffer.
///
/// Used by the `print!` and `println!` macros.
pub static ref WRITER: Mutex<Writer> = Mutex::new(Writer {
column_position: 0,
color_code: ColorCode::new(Color::Yellow, Color::Black),
buffer: unsafe { &mut *(0xb8000 as *mut Buffer) },
});
}
/// The standard color palette in VGA text mode.
#[allow(dead_code)]
#[derive(Debug, Clone, Copy, PartialEq, Eq)]
#[repr(u8)]
pub enum Color {
Black = 0,
Blue = 1,
Green = 2,
Cyan = 3,
Red = 4,
Magenta = 5,
Brown = 6,
LightGray = 7,
DarkGray = 8,
LightBlue = 9,
LightGreen = 10,
LightCyan = 11,
LightRed = 12,
Pink = 13,
Yellow = 14,
White = 15,
}
/// A combination of a foreground and a background color.
#[derive(Debug, Clone, Copy, PartialEq, Eq)]
#[repr(transparent)]
struct ColorCode(u8);
impl ColorCode {
/// Create a new `ColorCode` with the given foreground and background colors.
fn new(foreground: Color, background: Color) -> ColorCode {
ColorCode((background as u8) << 4 | (foreground as u8))
}
}
/// A screen character in the VGA text buffer, consisting of an ASCII character and a `ColorCode`.
#[derive(Debug, Clone, Copy, PartialEq, Eq)]
#[repr(C)]
struct ScreenChar {
ascii_character: u8,
color_code: ColorCode,
}
/// The height of the text buffer (normally 25 lines).
const BUFFER_HEIGHT: usize = 25;
/// The width of the text buffer (normally 80 columns).
const BUFFER_WIDTH: usize = 80;
/// A structure representing the VGA text buffer.
#[repr(transparent)]
struct Buffer {
chars: [[Volatile<ScreenChar>; BUFFER_WIDTH]; BUFFER_HEIGHT],
}
/// A writer type that allows writing ASCII bytes and strings to an underlying `Buffer`.
///
/// Wraps lines at `BUFFER_WIDTH`. Supports newline characters and implements the
/// `core::fmt::Write` trait.
pub struct Writer {
column_position: usize,
color_code: ColorCode,
buffer: &'static mut Buffer,
}
impl Writer {
/// Writes an ASCII byte to the buffer.
///
/// Wraps lines at `BUFFER_WIDTH`. Supports the `\n` newline character.
pub fn write_byte(&mut self, byte: u8) {
match byte {
b'\n' => self.new_line(),
byte => {
if self.column_position >= BUFFER_WIDTH {
self.new_line();
}
let row = BUFFER_HEIGHT - 1;
let col = self.column_position;
let color_code = self.color_code;
self.buffer.chars[row][col].write(ScreenChar {
ascii_character: byte,
color_code,
});
self.column_position += 1;
}
}
}
/// Writes the given ASCII string to the buffer.
///
/// Wraps lines at `BUFFER_WIDTH`. Supports the `\n` newline character. Does **not**
/// support strings with non-ASCII characters, since they can't be printed in the VGA text
/// mode.
fn write_string(&mut self, s: &str) {
for byte in s.bytes() {
match byte {
// printable ASCII byte or newline
0x20..=0x7e | b'\n' => self.write_byte(byte),
// not part of printable ASCII range
_ => self.write_byte(0xfe),
}
}
}
/// Shifts all lines one line up and clears the last row.
fn new_line(&mut self) {
for row in 1..BUFFER_HEIGHT {
for col in 0..BUFFER_WIDTH {
let character = self.buffer.chars[row][col].read();
self.buffer.chars[row - 1][col].write(character);
}
}
self.clear_row(BUFFER_HEIGHT - 1);
self.column_position = 0;
}
/// Clears a row by overwriting it with blank characters.
fn clear_row(&mut self, row: usize) {
let blank = ScreenChar {
ascii_character: b' ',
color_code: self.color_code,
};
for col in 0..BUFFER_WIDTH {
self.buffer.chars[row][col].write(blank);
}
}
}
impl fmt::Write for Writer {
fn write_str(&mut self, s: &str) -> fmt::Result {
self.write_string(s);
Ok(())
}
}
/// Like the `print!` macro in the standard library, but prints to the VGA text buffer.
#[macro_export]
macro_rules! print {
($($arg:tt)*) => ($crate::vga_buffer::_print(format_args!($($arg)*)));
}
/// Like the `println!` macro in the standard library, but prints to the VGA text buffer.
#[macro_export]
macro_rules! println {
() => ($crate::print!("\n"));
($($arg:tt)*) => ($crate::print!("{}\n", format_args!($($arg)*)));
}
/// 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();
});
}
#[test_case]
fn test_println_simple() {
serial_print!("test_println... ");
println!("test_println_simple output");
serial_println!("[ok]");
}
#[test_case]
fn test_println_many() {
serial_print!("test_println_many... ");
for _ in 0..200 {
println!("test_println_many output");
}
serial_println!("[ok]");
}
#[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);
}
});
serial_println!("[ok]");
}

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@@ -1,27 +0,0 @@
#![no_std]
#![no_main]
#![feature(custom_test_frameworks)]
#![test_runner(blog_os::test_runner)]
#![reexport_test_harness_main = "test_main"]
use blog_os::{println, serial_print, serial_println};
use core::panic::PanicInfo;
#[no_mangle] // don't mangle the name of this function
pub extern "C" fn _start() -> ! {
test_main();
loop {}
}
#[panic_handler]
fn panic(info: &PanicInfo) -> ! {
blog_os::test_panic_handler(info)
}
#[test_case]
fn test_println() {
serial_print!("test_println... ");
println!("test_println output");
serial_println!("[ok]");
}

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@@ -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)
}

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@@ -1,25 +0,0 @@
#![no_std]
#![no_main]
use blog_os::{exit_qemu, serial_print, serial_println, QemuExitCode};
use core::panic::PanicInfo;
#[no_mangle]
pub extern "C" fn _start() -> ! {
should_fail();
serial_println!("[test did not panic]");
exit_qemu(QemuExitCode::Failed);
loop {}
}
fn should_fail() {
serial_print!("should_fail... ");
assert_eq!(0, 1);
}
#[panic_handler]
fn panic(_info: &PanicInfo) -> ! {
serial_println!("[ok]");
exit_qemu(QemuExitCode::Success);
loop {}
}

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@@ -1,57 +0,0 @@
#![no_std]
#![no_main]
#![feature(abi_x86_interrupt)]
use blog_os::{exit_qemu, serial_print, serial_println, QemuExitCode};
use core::panic::PanicInfo;
use lazy_static::lazy_static;
use x86_64::structures::idt::{InterruptDescriptorTable, InterruptStackFrame};
#[no_mangle]
pub extern "C" fn _start() -> ! {
serial_print!("stack_overflow... ");
blog_os::gdt::init();
init_test_idt();
// trigger a stack overflow
stack_overflow();
panic!("Execution continued after stack overflow");
}
#[allow(unconditional_recursion)]
fn stack_overflow() {
stack_overflow(); // for each recursion, the return address is pushed
}
lazy_static! {
static ref TEST_IDT: InterruptDescriptorTable = {
let mut idt = InterruptDescriptorTable::new();
unsafe {
idt.double_fault
.set_handler_fn(test_double_fault_handler)
.set_stack_index(blog_os::gdt::DOUBLE_FAULT_IST_INDEX);
}
idt
};
}
pub fn init_test_idt() {
TEST_IDT.load();
}
extern "x86-interrupt" fn test_double_fault_handler(
_stack_frame: &mut InterruptStackFrame,
_error_code: u64,
) -> ! {
serial_println!("[ok]");
exit_qemu(QemuExitCode::Success);
loop {}
}
#[panic_handler]
fn panic(info: &PanicInfo) -> ! {
blog_os::test_panic_handler(info)
}

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@@ -1,15 +0,0 @@
{
"llvm-target": "x86_64-unknown-none",
"data-layout": "e-m:e-i64:64-f80:128-n8:16:32:64-S128",
"arch": "x86_64",
"target-endian": "little",
"target-pointer-width": "64",
"target-c-int-width": "32",
"os": "none",
"executables": true,
"linker-flavor": "ld.lld",
"linker": "rust-lld",
"panic-strategy": "abort",
"disable-redzone": true,
"features": "-mmx,-sse,+soft-float"
}