Merge branch 'post-09' into post-10

Fix: `target-pointer-width` field now expects an integer

.cargo/config

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

.cargo/config.toml

@@ -0,0 +1,9 @@
+[unstable]
+build-std = ["core", "compiler_builtins", "alloc"]
+build-std-features = ["compiler-builtins-mem"]
+
+[build]
+target = "x86_64-blog_os.json"
+
+[target.'cfg(target_os = "none")']
+runner = "bootimage runner"

.github/workflows/build-code.yml

@@ -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

.github/workflows/code.yml

@@ -0,0 +1,130 @@
+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: ${{ matrix.platform }}
+    steps:
+      - name: Install Rust Toolchain
+        uses: actions-rs/toolchain@v1
+        with:
+          profile: minimal
+          toolchain: nightly
+      - name: Install bootimage
+        run: cargo install bootimage --debug
+      - name: Checkout Repository
+        uses: actions/checkout@v2
+      - name: Install Rustup Components
+        run: rustup component add rust-src llvm-tools-preview
+      - name: Run `cargo bootimage`
+        uses: actions-rs/cargo@v1
+        with:
+          command: bootimage
+
+      # install QEMU
+      - name: Install QEMU (Linux)
+        run: sudo apt update && sudo apt install qemu-system-x86
+        if: runner.os == 'Linux'
+      - name: Install QEMU (macOS)
+        run: brew install qemu
+        if: runner.os == 'macOS'
+        env:
+          HOMEBREW_NO_AUTO_UPDATE: 1
+          HOMEBREW_NO_BOTTLE_SOURCE_FALLBACK: 1
+          HOMEBREW_NO_INSTALL_CLEANUP: 1
+      - name: Install QEMU (Windows)
+        run: |
+          choco install qemu --version 2021.5.5
+          echo "$Env:Programfiles\qemu" | Out-File -FilePath $env:GITHUB_PATH -Encoding utf8 -Append
+        if: runner.os == 'Windows'
+        shell: pwsh
+      - name: "Print QEMU Version"
+        run: qemu-system-x86_64 --version
+
+      - name: Run `cargo test`
+        uses: actions-rs/cargo@v1
+        with:
+          command: test
+
+  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

Cargo.lock

@@ -1,170 +1,106 @@
 # This file is automatically @generated by Cargo.
 # It is not intended for manual editing.
+version = 4
+
 [[package]]
 name = "autocfg"
-version = "1.0.0"
+version = "1.5.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "f8aac770f1885fd7e387acedd76065302551364496e46b3dd00860b2f8359b9d"
+checksum = "c08606f8c3cbf4ce6ec8e28fb0014a2c086708fe954eaa885384a6165172e7e8"
 
 [[package]]
 name = "bit_field"
-version = "0.9.0"
+version = "0.10.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "ed8765909f9009617974ab6b7d332625b320b33c326b1e9321382ef1999b5d56"
+checksum = "dc827186963e592360843fb5ba4b973e145841266c1357f7180c43526f2e5b61"
 
 [[package]]
 name = "bitflags"
-version = "1.2.1"
+version = "1.3.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "cf1de2fe8c75bc145a2f577add951f8134889b4795d47466a54a5c846d691693"
+checksum = "bef38d45163c2f1dde094a7dfd33ccf595c92905c8f8f4fdc18d06fb1037718a"
+
+[[package]]
+name = "bitflags"
+version = "2.9.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "6a65b545ab31d687cff52899d4890855fec459eb6afe0da6417b8a18da87aa29"
 
 [[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",
+ "pic8259",
- "spin",
+ "spin 0.5.2",
  "uart_16550",
- "volatile",
+ "volatile 0.2.7",
  "x86_64",
 ]
 
 [[package]]
 name = "bootloader"
-version = "0.8.8"
+version = "0.9.33"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "c3ed4f735c4e455ba86a3d2939b1c0729414153642106c9d035693355630a42c"
+checksum = "7bdfddac270bbdd45903296bc1caf29a7fdce6b326aaf0bbab7f04c5f98b7447"
-
-[[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"
+version = "1.5.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "e2abad23fbc42b3700f2f279844dc832adb2b2eb069b2df918f455c4e18cc646"
+checksum = "bbd2bcb4c963f2ddae06a2efc7e9f3591312473c50c6685e1f298068316e66fe"
 dependencies = [
- "spin",
+ "spin 0.9.8",
 ]
 
 [[package]]
 name = "linked_list_allocator"
-version = "0.8.0"
+version = "0.9.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "18c618c431dfe4419afbe22852f6aceffbc17bd82ba0a18b982def291000824c"
+checksum = "549ce1740e46b291953c4340adcd74c59bcf4308f4cac050fd33ba91b7168f4a"
 dependencies = [
  "spinning_top",
 ]
 
 [[package]]
 name = "lock_api"
-version = "0.3.3"
+version = "0.4.13"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "79b2de95ecb4691949fea4716ca53cdbcfccb2c612e19644a8bad05edcf9f47b"
+checksum = "96936507f153605bddfcda068dd804796c84324ed2510809e5b2a624c81da765"
 dependencies = [
+ "autocfg",
  "scopeguard",
 ]
 
 [[package]]
 name = "pc-keyboard"
-version = "0.5.0"
+version = "0.7.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "c48392db76c4e9a69e0b3be356c5f97ebb7b14413c5e4fd0af4755dbf86e2fce"
+checksum = "ed089a1fbffe3337a1a345501c981f1eb1e47e69de5a40e852433e12953c3174"
 
 [[package]]
-name = "pic8259_simple"
+name = "pic8259"
-version = "0.1.1"
+version = "0.10.4"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "dc64b2fd10828da8521b6cdabe0679385d7d2a3a6d4c336b819d1fa31ba35c72"
+checksum = "cb844b5b01db1e0b17938685738f113bfc903846f18932b378bc0eabfa40e194"
 dependencies = [
- "cpuio",
+ "x86_64",
 ]
 
 [[package]]
-name = "pin-utils"
+name = "rustversion"
-version = "0.1.0-alpha.4"
+version = "1.0.22"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "5894c618ce612a3fa23881b152b608bafb8c56cfc22f434a3ba3120b40f7b587"
+checksum = "b39cdef0fa800fc44525c84ccb54a029961a8215f9619753635a9c0d2538d46d"
 
 [[package]]
 name = "scopeguard"
-version = "1.1.0"
+version = "1.2.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "d29ab0c6d3fc0ee92fe66e2d99f700eab17a8d57d1c1d3b748380fb20baa78cd"
+checksum = "94143f37725109f92c262ed2cf5e59bce7498c01bcc1502d7b9afe439a4e9f49"
 
 [[package]]
 name = "spin"
@@ -173,36 +109,51 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "6e63cff320ae2c57904679ba7cb63280a3dc4613885beafb148ee7bf9aa9042d"
 
 [[package]]
-name = "spinning_top"
+name = "spin"
-version = "0.1.0"
+version = "0.9.8"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "32d801a3a53bcf5071f85fef8d5cab9e5f638fc5580a37e6eb7aba4b37438d24"
+checksum = "6980e8d7511241f8acf4aebddbb1ff938df5eebe98691418c4468d0b72a96a67"
+
+[[package]]
+name = "spinning_top"
+version = "0.2.5"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "5b9eb1a2f4c41445a3a0ff9abc5221c5fcd28e1f13cd7c0397706f9ac938ddb0"
 dependencies = [
  "lock_api",
 ]
 
 [[package]]
 name = "uart_16550"
-version = "0.2.4"
+version = "0.2.19"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "d44b0f30cb82b0fbc15b78ade1064226529ad52028bc8cb8accb98ff6f3d7131"
+checksum = "614ff2a87880d4bd4374722268598a970bbad05ced8bf630439417347254ab2e"
 dependencies = [
- "bitflags",
+ "bitflags 1.3.2",
+ "rustversion",
  "x86_64",
 ]
 
 [[package]]
 name = "volatile"
-version = "0.2.6"
+version = "0.2.7"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "6af0edf5b4faacc31fc51159244d78d65ec580f021afcef7bd53c04aeabc7f29"
+checksum = "f6b06ad3ed06fef1713569d547cdbdb439eafed76341820fb0e0344f29a41945"
+
+[[package]]
+name = "volatile"
+version = "0.4.6"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "442887c63f2c839b346c192d047a7c87e73d0689c9157b00b53dcc27dd5ea793"
 
 [[package]]
 name = "x86_64"
-version = "0.9.6"
+version = "0.14.13"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "4206b60c9f99766329b66962aa8ddc01df6c7edd02edc046b7a69d5df9fcdbcf"
+checksum = "c101112411baafbb4bf8d33e4c4a80ab5b02d74d2612331c61e8192fc9710491"
 dependencies = [
  "bit_field",
- "bitflags",
+ "bitflags 2.9.2",
+ "rustversion",
+ "volatile 0.4.6",
 ]

Cargo.toml

@@ -2,7 +2,7 @@
 name = "blog_os"
 version = "0.1.0"
 authors = ["Philipp Oppermann <dev@phil-opp.com>"]
-edition = "2018"
+edition = "2024"
 
 [[test]]
 name = "should_panic"
@@ -13,36 +13,32 @@ name = "stack_overflow"
 harness = false
 
 [dependencies]
-bootloader = { version = "0.8.0", features = ["map_physical_memory"]}
+bootloader = { version = "0.9", features = ["map_physical_memory"] }
 volatile = "0.2.6"
 spin = "0.5.2"
-x86_64 = "0.9.6"
+x86_64 = "0.14.2"
 uart_16550 = "0.2.0"
-pic8259_simple = "0.1.1"
+pic8259 = "0.10.1"
-pc-keyboard = "0.5.0"
+pc-keyboard = "0.7.0"
-linked_list_allocator = "0.8.0"
+linked_list_allocator = "0.9.0"
 
 [dependencies.lazy_static]
 version = "1.0"
 features = ["spin_no_std"]
 
-[dependencies.crossbeam-queue]
+[[bin]]
-version = "0.2.1"
+name = "blog_os"
-default-features = false
+test = true
-features = ["alloc"]
+bench = false
 
-[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",
+    "-device",
-    "-display", "none"
+    "isa-debug-exit,iobase=0xf4,iosize=0x04",
+    "-serial",
+    "stdio",
+    "-display",
+    "none",
 ]
-test-success-exit-code = 33         # (0x10 << 1) | 1
+test-success-exit-code = 33 # (0x10 << 1) | 1

README.md

@@ -1,6 +1,6 @@
 # Blog OS (Heap Allocation)
 
-[![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-10)](https://github.com/phil-opp/blog_os/actions?query=workflow%3A%22Code%22+branch%3Apost-10)
 
 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.
 
@@ -10,19 +10,23 @@ This repository contains the source code for the [Heap Allocation][post] post of
 
 ## Building
 
-You need a nightly Rust compiler. First you need to install the `cargo-xbuild` and `bootimage` tools:
+This project requires a nightly version of Rust because it uses some unstable features. At least nightly _2020-07-15_ is required for building. You might need to run `rustup update nightly --force` to update to the latest nightly even if some components such as `rustfmt` are missing it.
+
+You can build the project by running:
 
 ```
-cargo install cargo-xbuild bootimage
+cargo build
 ```
 
-Then you can build the project by running:
+To create a bootable disk image from the compiled kernel, you need to install the [`bootimage`] tool:
+
+[`bootimage`]: https://github.com/rust-osdev/bootimage
 
 ```
-cargo xbuild
+cargo install bootimage
 ```
 
-To create a bootable disk image, run:
+After installing, you can create the bootable disk image by running:
 
 ```
 cargo bootimage
@@ -39,10 +43,10 @@ You can run the disk image in [QEMU] through:
 [QEMU]: https://www.qemu.org/
 
 ```
-cargo xrun
+cargo run
 ```
 
-Of course [QEMU] needs to be installed for this.
+[QEMU] and the [`bootimage`] tool need 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:
 

src/allocator.rs

@@ -1,22 +1,18 @@
 use alloc::alloc::{GlobalAlloc, Layout};
 use core::ptr::null_mut;
-use fixed_size_block::FixedSizeBlockAllocator;
+use linked_list_allocator::LockedHeap;
 use x86_64::{
-    structures::paging::{
-        mapper::MapToError, FrameAllocator, Mapper, Page, PageTableFlags, Size4KiB,
-    },
     VirtAddr,
+    structures::paging::{
+        FrameAllocator, Mapper, Page, PageTableFlags, Size4KiB, mapper::MapToError,
+    },
 };
 
-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());
+static ALLOCATOR: LockedHeap = LockedHeap::empty();
 
 pub fn init_heap(
     mapper: &mut impl Mapper<Size4KiB>,
@@ -35,7 +31,7 @@ pub fn init_heap(
             .allocate_frame()
             .ok_or(MapToError::FrameAllocationFailed)?;
         let flags = PageTableFlags::PRESENT | PageTableFlags::WRITABLE;
-        mapper.map_to(page, frame, flags, frame_allocator)?.flush();
+        unsafe { mapper.map_to(page, frame, flags, frame_allocator)?.flush() };
     }
 
     unsafe {
@@ -56,27 +52,3 @@ unsafe impl GlobalAlloc for Dummy {
         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)
-}

src/allocator/bump.rs

@@ -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;
-        }
-    }
-}

src/allocator/fixed_size_block.rs

@@ -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);
-            }
-        }
-    }
-}

src/allocator/linked_list.rs

@@ -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)
-    }
-}

src/driver/keyboard.rs

@@ -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),
-                }
-            }
-        }
-    }
-}

src/driver/mod.rs

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

src/driver/timer.rs

@@ -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!(".");
-    }
-}

src/gdt.rs

@@ -1,7 +1,7 @@
 use lazy_static::lazy_static;
+use x86_64::VirtAddr;
 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;
 
@@ -9,10 +9,10 @@ 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;
+            const STACK_SIZE: usize = 4096 * 5;
             static mut STACK: [u8; STACK_SIZE] = [0; STACK_SIZE];
 
-            let stack_start = VirtAddr::from_ptr(unsafe { &STACK });
+            let stack_start = VirtAddr::from_ptr(&raw const STACK);
             let stack_end = stack_start + STACK_SIZE;
             stack_end
         };
@@ -41,12 +41,12 @@ struct Selectors {
 }
 
 pub fn init() {
-    use x86_64::instructions::segmentation::set_cs;
+    use x86_64::instructions::segmentation::{CS, Segment};
     use x86_64::instructions::tables::load_tss;
 
     GDT.0.load();
     unsafe {
-        set_cs(GDT.1.code_selector);
+        CS::set_reg(GDT.1.code_selector);
         load_tss(GDT.1.tss_selector);
     }
 }

src/interrupts.rs

@@ -1,6 +1,6 @@
-use crate::{gdt, hlt_loop, println};
+use crate::{gdt, hlt_loop, print, println};
 use lazy_static::lazy_static;
-use pic8259_simple::ChainedPics;
+use pic8259::ChainedPics;
 use spin;
 use x86_64::structures::idt::{InterruptDescriptorTable, InterruptStackFrame, PageFaultErrorCode};
 
@@ -47,12 +47,12 @@ pub fn init_idt() {
     IDT.load();
 }
 
-extern "x86-interrupt" fn breakpoint_handler(stack_frame: &mut InterruptStackFrame) {
+extern "x86-interrupt" fn breakpoint_handler(stack_frame: InterruptStackFrame) {
     println!("EXCEPTION: BREAKPOINT\n{:#?}", stack_frame);
 }
 
 extern "x86-interrupt" fn page_fault_handler(
-    stack_frame: &mut InterruptStackFrame,
+    stack_frame: InterruptStackFrame,
     error_code: PageFaultErrorCode,
 ) {
     use x86_64::registers::control::Cr2;
@@ -65,27 +65,46 @@ extern "x86-interrupt" fn page_fault_handler(
 }
 
 extern "x86-interrupt" fn double_fault_handler(
-    stack_frame: &mut InterruptStackFrame,
+    stack_frame: InterruptStackFrame,
     _error_code: u64,
 ) -> ! {
     panic!("EXCEPTION: DOUBLE FAULT\n{:#?}", stack_frame);
 }
 
-extern "x86-interrupt" fn timer_interrupt_handler(_stack_frame: &mut InterruptStackFrame) {
+extern "x86-interrupt" fn timer_interrupt_handler(_stack_frame: InterruptStackFrame) {
-    crate::driver::timer::tick();
+    print!(".");
-
     unsafe {
         PICS.lock()
             .notify_end_of_interrupt(InterruptIndex::Timer.as_u8());
     }
 }
 
-extern "x86-interrupt" fn keyboard_interrupt_handler(_stack_frame: &mut InterruptStackFrame) {
+extern "x86-interrupt" fn keyboard_interrupt_handler(_stack_frame: InterruptStackFrame) {
+    use pc_keyboard::{DecodedKey, HandleControl, Keyboard, ScancodeSet1, layouts};
+    use spin::Mutex;
     use x86_64::instructions::port::Port;
-    let mut port = Port::new(0x60);
-    let scancode: u8 = unsafe { port.read() };
 
-    crate::driver::keyboard::keyboard_scancode(scancode);
+    lazy_static! {
+        static ref KEYBOARD: Mutex<Keyboard<layouts::Us104Key, ScancodeSet1>> =
+            Mutex::new(Keyboard::new(
+                ScancodeSet1::new(),
+                layouts::Us104Key,
+                HandleControl::Ignore
+            ));
+    }
+
+    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()
@@ -93,13 +112,8 @@ extern "x86-interrupt" fn keyboard_interrupt_handler(_stack_frame: &mut Interrup
     }
 }
 
-#[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]");
 }

src/lib.rs

@@ -2,44 +2,44 @@
 #![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() };
+    x86_64::instructions::interrupts::enable();
+}
+pub trait Testable {
+    fn run(&self) -> ();
 }
 
-pub fn init_heap_structures() {
+impl<T> Testable for T
-    task::init();
+where
-    driver::init();
+    T: Fn(),
+{
+    fn run(&self) {
+        serial_print!("{}...\t", core::any::type_name::<T>());
+        self();
+        serial_println!("[ok]");
+    }
 }
 
-pub fn test_runner(tests: &[&dyn Fn()]) {
+pub fn test_runner(tests: &[&dyn Testable]) {
     serial_println!("Running {} tests", tests.len());
     for test in tests {
-        test();
+        test.run();
     }
     exit_qemu(QemuExitCode::Success);
 }
@@ -74,7 +74,7 @@ pub fn hlt_loop() -> ! {
 }
 
 #[cfg(test)]
-use bootloader::{entry_point, BootInfo};
+use bootloader::{BootInfo, entry_point};
 
 #[cfg(test)]
 entry_point!(test_kernel_main);
@@ -92,8 +92,3 @@ 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)
-}

src/main.rs

@@ -8,7 +8,7 @@ extern crate alloc;
 
 use alloc::{boxed::Box, rc::Rc, vec, vec::Vec};
 use blog_os::println;
-use bootloader::{entry_point, BootInfo};
+use bootloader::{BootInfo, entry_point};
 use core::panic::PanicInfo;
 
 entry_point!(kernel_main);
@@ -26,7 +26,6 @@ fn kernel_main(boot_info: &'static BootInfo) -> ! {
     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);
@@ -52,24 +51,11 @@ fn kernel_main(boot_info: &'static BootInfo) -> ! {
         Rc::strong_count(&cloned_reference)
     );
 
-    use blog_os::task::executor::Executor;
+    #[cfg(test)]
+    test_main();
 
-    let mut executor = Executor::new();
+    println!("It did not crash!");
-    executor.spawn(bar());
+    blog_os::hlt_loop();
-
-    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();
 }
 
 /// This function is called on panic.
@@ -86,14 +72,7 @@ fn panic(info: &PanicInfo) -> ! {
     blog_os::test_panic_handler(info)
 }
 
-async fn test() -> u32 {
+#[test_case]
-    42
+fn trivial_assertion() {
-}
+    assert_eq!(1, 1);
-
-async fn foo() -> u32 {
-    test().await * 2
-}
-
-async fn bar() {
-    println!("foo result: {}", foo().await);
 }

src/memory.rs

@@ -1,10 +1,7 @@
 use bootloader::bootinfo::{MemoryMap, MemoryRegionType};
 use x86_64::{
-    structures::paging::{
-        FrameAllocator, Mapper, OffsetPageTable, Page, PageTable, PhysFrame, Size4KiB,
-        UnusedPhysFrame,
-    },
     PhysAddr, VirtAddr,
+    structures::paging::{FrameAllocator, OffsetPageTable, PageTable, PhysFrame, Size4KiB},
 };
 
 /// Initialize a new OffsetPageTable.
@@ -14,8 +11,10 @@ use x86_64::{
 /// `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);
+    unsafe {
-    OffsetPageTable::new(level_4_table, physical_memory_offset)
+        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.
@@ -33,31 +32,14 @@ unsafe fn active_level_4_table(physical_memory_offset: VirtAddr) -> &'static mut
     let virt = physical_memory_offset + phys.as_u64();
     let page_table_ptr: *mut PageTable = virt.as_mut_ptr();
 
-    &mut *page_table_ptr // unsafe
+    unsafe { &mut *page_table_ptr }
-}
-
-/// 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> {
+    fn allocate_frame(&mut self) -> Option<PhysFrame> {
         None
     }
 }
@@ -82,7 +64,7 @@ impl BootInfoFrameAllocator {
     }
 
     /// Returns an iterator over the usable frames specified in the memory map.
-    fn usable_frames(&self) -> impl Iterator<Item = UnusedPhysFrame> {
+    fn usable_frames(&self) -> impl Iterator<Item = PhysFrame> {
         // get usable regions from memory map
         let regions = self.memory_map.iter();
         let usable_regions = regions.filter(|r| r.region_type == MemoryRegionType::Usable);
@@ -91,14 +73,12 @@ impl BootInfoFrameAllocator {
         // 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)));
+        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> {
+    fn allocate_frame(&mut self) -> Option<PhysFrame> {
         let frame = self.usable_frames().nth(self.next);
         self.next += 1;
         frame

src/task/executor.rs

@@ -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);
-    }
-}

src/task/interrupt_wakeups.rs

@@ -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")
-}

src/task/mod.rs

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

src/vga_buffer.rs

@@ -3,9 +3,6 @@ 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.
     ///
@@ -180,18 +177,14 @@ pub fn _print(args: fmt::Arguments) {
 
 #[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]
@@ -199,8 +192,6 @@ 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();
@@ -210,6 +201,4 @@ fn test_println_output() {
             assert_eq!(char::from(screen_char.ascii_character), c);
         }
     });
-
-    serial_println!("[ok]");
 }

tests/basic_boot.rs

@@ -4,10 +4,10 @@
 #![test_runner(blog_os::test_runner)]
 #![reexport_test_harness_main = "test_main"]
 
-use blog_os::{println, serial_print, serial_println};
+use blog_os::println;
 use core::panic::PanicInfo;
 
-#[no_mangle] // don't mangle the name of this function
+#[unsafe(no_mangle)] // don't mangle the name of this function
 pub extern "C" fn _start() -> ! {
     test_main();
 
@@ -21,7 +21,5 @@ fn panic(info: &PanicInfo) -> ! {
 
 #[test_case]
 fn test_println() {
-    serial_print!("test_println... ");
     println!("test_println output");
-    serial_println!("[ok]");
 }

tests/heap_allocation.rs

@@ -7,8 +7,8 @@
 extern crate alloc;
 
 use alloc::{boxed::Box, vec::Vec};
-use blog_os::{allocator::HEAP_SIZE, serial_print, serial_println};
+use blog_os::allocator::HEAP_SIZE;
-use bootloader::{entry_point, BootInfo};
+use bootloader::{BootInfo, entry_point};
 use core::panic::PanicInfo;
 
 entry_point!(main);
@@ -30,44 +30,28 @@ fn main(boot_info: &'static BootInfo) -> ! {
 
 #[test_case]
 fn simple_allocation() {
-    serial_print!("simple_allocation... ");
+    let heap_value_1 = Box::new(41);
-    let heap_value = Box::new(41);
+    let heap_value_2 = Box::new(13);
-    assert_eq!(*heap_value, 41);
+    assert_eq!(*heap_value_1, 41);
-    serial_println!("[ok]");
+    assert_eq!(*heap_value_2, 13);
 }
 
 #[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]

tests/should_panic.rs

@@ -1,10 +1,10 @@
 #![no_std]
 #![no_main]
 
-use blog_os::{exit_qemu, serial_print, serial_println, QemuExitCode};
+use blog_os::{QemuExitCode, exit_qemu, serial_print, serial_println};
 use core::panic::PanicInfo;
 
-#[no_mangle]
+#[unsafe(no_mangle)]
 pub extern "C" fn _start() -> ! {
     should_fail();
     serial_println!("[test did not panic]");
@@ -13,7 +13,7 @@ pub extern "C" fn _start() -> ! {
 }
 
 fn should_fail() {
-    serial_print!("should_fail... ");
+    serial_print!("should_panic::should_fail...\t");
     assert_eq!(0, 1);
 }
 

tests/stack_overflow.rs

@@ -2,14 +2,14 @@
 #![no_main]
 #![feature(abi_x86_interrupt)]
 
-use blog_os::{exit_qemu, serial_print, serial_println, QemuExitCode};
+use blog_os::{QemuExitCode, exit_qemu, serial_print, serial_println};
 use core::panic::PanicInfo;
 use lazy_static::lazy_static;
 use x86_64::structures::idt::{InterruptDescriptorTable, InterruptStackFrame};
 
-#[no_mangle]
+#[unsafe(no_mangle)]
 pub extern "C" fn _start() -> ! {
-    serial_print!("stack_overflow... ");
+    serial_print!("stack_overflow::stack_overflow...\t");
 
     blog_os::gdt::init();
     init_test_idt();
@@ -23,6 +23,7 @@ pub extern "C" fn _start() -> ! {
 #[allow(unconditional_recursion)]
 fn stack_overflow() {
     stack_overflow(); // for each recursion, the return address is pushed
+    volatile::Volatile::new(0).read(); // prevent tail recursion optimizations
 }
 
 lazy_static! {
@@ -43,7 +44,7 @@ pub fn init_test_idt() {
 }
 
 extern "x86-interrupt" fn test_double_fault_handler(
-    _stack_frame: &mut InterruptStackFrame,
+    _stack_frame: InterruptStackFrame,
     _error_code: u64,
 ) -> ! {
     serial_println!("[ok]");

x86_64-blog_os.json

@@ -1,15 +1,16 @@
 {
     "llvm-target": "x86_64-unknown-none",
-    "data-layout": "e-m:e-i64:64-f80:128-n8:16:32:64-S128",
+    "data-layout": "e-m:e-p270:32:32-p271:32:32-p272:64:64-i64:64-i128:128-f80:128-n8:16:32:64-S128",
     "arch": "x86_64",
     "target-endian": "little",
-    "target-pointer-width": "64",
+    "target-pointer-width": 64,
-    "target-c-int-width": "32",
+    "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"
+    "features": "-mmx,-sse,+soft-float",
+    "rustc-abi": "x86-softfloat"
   }