From c1064ad3169d2e6d4c2e73a2d5318db1f88421f6 Mon Sep 17 00:00:00 2001
From: Philipp Oppermann <dev@phil-opp.com>
Date: Sat, 20 Apr 2019 18:05:13 +0200
Subject: [PATCH 01/27] Add a .cargo/config file

---
 .cargo/config | 5 +++++
 1 file changed, 5 insertions(+)
 create mode 100644 .cargo/config

diff --git a/.cargo/config b/.cargo/config
new file mode 100644
index 00000000..7f2ad55d
--- /dev/null
+++ b/.cargo/config
@@ -0,0 +1,5 @@
+[build]
+target = "x86_64-blog_os.json"
+
+[target.'cfg(target_os = "none")']
+runner = "bootimage runner"

From 06d1c9ff81295b0dc13f60e06454740d70a8c881 Mon Sep 17 00:00:00 2001
From: Philipp Oppermann <dev@phil-opp.com>
Date: Sat, 20 Apr 2019 18:06:02 +0200
Subject: [PATCH 02/27] Update CI scripts to use `cargo bootimage`

---
 .appveyor.yml       | 2 +-
 .travis.yml         | 5 ++---
 azure-pipelines.yml | 6 ++----
 3 files changed, 5 insertions(+), 8 deletions(-)

diff --git a/.appveyor.yml b/.appveyor.yml
index 7c4bd1c0..ad43a498 100644
--- a/.appveyor.yml
+++ b/.appveyor.yml
@@ -73,4 +73,4 @@ before_test:
   - cargo install-latest cargo-xbuild bootimage
 
 test_script:
-  - bootimage build
+  - cargo bootimage
diff --git a/.travis.yml b/.travis.yml
index a6f58578..ff2ad445 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -30,9 +30,8 @@ cache:
 
 before_script:
   - rustup component add rust-src llvm-tools-preview
-  - (test -x $HOME/.cargo/bin/cargo-install-latest || cargo install cargo-install-latest)
-  - cargo install-latest cargo-xbuild bootimage cargo-cache
+  - cargo install cargo-xbuild bootimage cargo-cache --debug -Z install-upgrade
 
 script:
-  - bootimage build
+  - cargo bootimage
   - cargo cache --autoclean
diff --git a/azure-pipelines.yml b/azure-pipelines.yml
index 5b43f03d..8a3dcda1 100644
--- a/azure-pipelines.yml
+++ b/azure-pipelines.yml
@@ -52,12 +52,10 @@ steps:
 - script: rustup component add rust-src llvm-tools-preview
   displayName: 'Install Rustup Components'
 
-- script: |
-    cargo install cargo-xbuild --debug
-    cargo install bootimage --debug
+- script: cargo install cargo-xbuild bootimage --debug
   displayName: 'Install cargo-xbuild and bootimage'
 
-- script: bootimage build
+- script: cargo bootimage
   displayName: 'Build'
 
 - script: rustup component add rustfmt

From 528bbd4e9fb90cf1e730cefd932112702c078c2f Mon Sep 17 00:00:00 2001
From: Philipp Oppermann <dev@phil-opp.com>
Date: Thu, 25 Apr 2019 14:28:43 +0200
Subject: [PATCH 03/27] Add a `cargo xbuild` check on CI

---
 .appveyor.yml       | 1 +
 .travis.yml         | 1 +
 azure-pipelines.yml | 5 ++++-
 3 files changed, 6 insertions(+), 1 deletion(-)

diff --git a/.appveyor.yml b/.appveyor.yml
index ad43a498..423cc6db 100644
--- a/.appveyor.yml
+++ b/.appveyor.yml
@@ -73,4 +73,5 @@ before_test:
   - cargo install-latest cargo-xbuild bootimage
 
 test_script:
+  - cargo xbuild
   - cargo bootimage
diff --git a/.travis.yml b/.travis.yml
index ff2ad445..1e6697ca 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -33,5 +33,6 @@ before_script:
   - cargo install cargo-xbuild bootimage cargo-cache --debug -Z install-upgrade
 
 script:
+  - cargo xbuild
   - cargo bootimage
   - cargo cache --autoclean
diff --git a/azure-pipelines.yml b/azure-pipelines.yml
index 8a3dcda1..672a9add 100644
--- a/azure-pipelines.yml
+++ b/azure-pipelines.yml
@@ -55,9 +55,12 @@ steps:
 - script: cargo install cargo-xbuild bootimage --debug
   displayName: 'Install cargo-xbuild and bootimage'
 
-- script: cargo bootimage
+- script: cargo xbuild
   displayName: 'Build'
 
+- script: cargo bootimage
+  displayName: 'Create Bootimage'
+
 - script: rustup component add rustfmt
   displayName: 'Install Rustfmt'
 

From 63b97fe1f85ec0ceec0a192c68a589089e6364ed Mon Sep 17 00:00:00 2001
From: Philipp Oppermann <dev@phil-opp.com>
Date: Fri, 26 Apr 2019 11:23:32 +0200
Subject: [PATCH 04/27] Update bootloader to version 0.6.0

---
 Cargo.lock | 6 +++---
 Cargo.toml | 2 +-
 2 files changed, 4 insertions(+), 4 deletions(-)

diff --git a/Cargo.lock b/Cargo.lock
index b30261fd..0bd7abdf 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -22,12 +22,12 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 name = "blog_os"
 version = "0.1.0"
 dependencies = [
- "bootloader 0.5.2 (registry+https://github.com/rust-lang/crates.io-index)",
+ "bootloader 0.6.0 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
 [[package]]
 name = "bootloader"
-version = "0.5.2"
+version = "0.6.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
  "fixedvec 0.2.3 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -215,7 +215,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 "checksum array-init 0.0.4 (registry+https://github.com/rust-lang/crates.io-index)" = "23589ecb866b460d3a0f1278834750268c607e8e28a1b982c907219f3178cd72"
 "checksum bit_field 0.9.0 (registry+https://github.com/rust-lang/crates.io-index)" = "ed8765909f9009617974ab6b7d332625b320b33c326b1e9321382ef1999b5d56"
 "checksum bitflags 1.0.4 (registry+https://github.com/rust-lang/crates.io-index)" = "228047a76f468627ca71776ecdebd732a3423081fcf5125585bcd7c49886ce12"
-"checksum bootloader 0.5.2 (registry+https://github.com/rust-lang/crates.io-index)" = "2735a1e3ddf16e6832fff86db617778dd3cecd5804fc8c2f20f448750d4c989c"
+"checksum bootloader 0.6.0 (registry+https://github.com/rust-lang/crates.io-index)" = "8654b1ebbd38d2a8687a451ad53466d01b5edc9d75ec63d676525a6103d77151"
 "checksum fixedvec 0.2.3 (registry+https://github.com/rust-lang/crates.io-index)" = "7c6c16d316ccdac21a4dd648e314e76facbbaf316e83ca137d0857a9c07419d0"
 "checksum font8x8 0.2.4 (registry+https://github.com/rust-lang/crates.io-index)" = "b81d84c3c978af7d05d31a2198af4b9ba956d819d15d8f6d58fc150e33f8dc1f"
 "checksum fuchsia-cprng 0.1.1 (registry+https://github.com/rust-lang/crates.io-index)" = "a06f77d526c1a601b7c4cdd98f54b5eaabffc14d5f2f0296febdc7f357c6d3ba"
diff --git a/Cargo.toml b/Cargo.toml
index affeefaf..26a84cf7 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -5,7 +5,7 @@ authors = ["Philipp Oppermann <dev@phil-opp.com>"]
 edition = "2018"
 
 [dependencies]
-bootloader = "0.5.1"
+bootloader = "0.6.0"
 
 [profile.dev]
 panic = "abort"

From b59720f6e112f5c1079ba649d50cdcf61139ef66 Mon Sep 17 00:00:00 2001
From: Philipp Oppermann <dev@phil-opp.com>
Date: Fri, 26 Apr 2019 11:27:36 +0200
Subject: [PATCH 05/27] Update Readme for new runner

---
 README.md | 10 ++++++++--
 1 file changed, 8 insertions(+), 2 deletions(-)

diff --git a/README.md b/README.md
index 2c264b11..66739f4b 100644
--- a/README.md
+++ b/README.md
@@ -19,7 +19,13 @@ cargo install cargo-xbuild bootimage
 Then you can build the project by running:
 
 ```
-bootimage build
+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.
@@ -33,7 +39,7 @@ You can run the disk image in [QEMU] through:
 [QEMU]: https://www.qemu.org/
 
 ```
-bootimage run
+cargo xrun
 ```
 
 Of course [QEMU] needs to be installed for this.

From 23cbafab1c10d178043709d7104bdefae41f8c3a Mon Sep 17 00:00:00 2001
From: Philipp Oppermann <dev@phil-opp.com>
Date: Thu, 25 Apr 2019 11:34:16 +0200
Subject: [PATCH 06/27] Reset code to post-03 branch

---
 Cargo.lock          | 10 ------
 Cargo.toml          |  3 --
 azure-pipelines.yml |  3 --
 src/main.rs         |  7 ++--
 src/vga_buffer.rs   | 83 ---------------------------------------------
 5 files changed, 2 insertions(+), 104 deletions(-)

diff --git a/Cargo.lock b/Cargo.lock
index e409fe78..ea2cc2e3 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -1,13 +1,5 @@
 # This file is automatically @generated by Cargo.
 # It is not intended for manual editing.
-[[package]]
-name = "array-init"
-version = "0.0.3"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-dependencies = [
- "nodrop 0.1.13 (registry+https://github.com/rust-lang/crates.io-index)",
-]
-
 [[package]]
 name = "array-init"
 version = "0.0.4"
@@ -30,7 +22,6 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 name = "blog_os"
 version = "0.1.0"
 dependencies = [
- "array-init 0.0.3 (registry+https://github.com/rust-lang/crates.io-index)",
  "bootloader 0.5.2 (registry+https://github.com/rust-lang/crates.io-index)",
  "lazy_static 1.3.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "spin 0.4.10 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -247,7 +238,6 @@ version = "0.1.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 
 [metadata]
-"checksum array-init 0.0.3 (registry+https://github.com/rust-lang/crates.io-index)" = "c3cc8456d0ae81a8c76f59e384683a601548c38949a4bfcb65dd31ded5c75ff3"
 "checksum array-init 0.0.4 (registry+https://github.com/rust-lang/crates.io-index)" = "23589ecb866b460d3a0f1278834750268c607e8e28a1b982c907219f3178cd72"
 "checksum bit_field 0.9.0 (registry+https://github.com/rust-lang/crates.io-index)" = "ed8765909f9009617974ab6b7d332625b320b33c326b1e9321382ef1999b5d56"
 "checksum bitflags 1.0.4 (registry+https://github.com/rust-lang/crates.io-index)" = "228047a76f468627ca71776ecdebd732a3423081fcf5125585bcd7c49886ce12"
diff --git a/Cargo.toml b/Cargo.toml
index b466cccb..afad8301 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -13,9 +13,6 @@ spin = "0.4.9"
 version = "1.0"
 features = ["spin_no_std"]
 
-[dev-dependencies]
-array-init = "0.0.3"
-
 [profile.dev]
 panic = "abort"
 
diff --git a/azure-pipelines.yml b/azure-pipelines.yml
index c6cc6936..5b43f03d 100644
--- a/azure-pipelines.yml
+++ b/azure-pipelines.yml
@@ -60,9 +60,6 @@ steps:
 - script: bootimage build
   displayName: 'Build'
 
-- script: cargo test
-  displayName: 'Unit Tests'
-
 - script: rustup component add rustfmt
   displayName: 'Install Rustfmt'
 
diff --git a/src/main.rs b/src/main.rs
index 319b9942..18e03650 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -1,12 +1,10 @@
-#![cfg_attr(not(test), no_std)]
-#![cfg_attr(not(test), no_main)]
-#![cfg_attr(test, allow(unused_imports))]
+#![no_std]
+#![no_main]
 
 use core::panic::PanicInfo;
 
 mod vga_buffer;
 
-#[cfg(not(test))]
 #[no_mangle]
 pub extern "C" fn _start() -> ! {
     println!("Hello World{}", "!");
@@ -15,7 +13,6 @@ pub extern "C" fn _start() -> ! {
 }
 
 /// This function is called on panic.
-#[cfg(not(test))]
 #[panic_handler]
 fn panic(info: &PanicInfo) -> ! {
     println!("{}", info);
diff --git a/src/vga_buffer.rs b/src/vga_buffer.rs
index d89b4948..94dbc4c6 100644
--- a/src/vga_buffer.rs
+++ b/src/vga_buffer.rs
@@ -169,86 +169,3 @@ pub fn _print(args: fmt::Arguments) {
     use core::fmt::Write;
     WRITER.lock().write_fmt(args).unwrap();
 }
-
-#[cfg(test)]
-mod test {
-    use super::*;
-
-    fn construct_writer() -> Writer {
-        use std::boxed::Box;
-
-        let buffer = construct_buffer();
-        Writer {
-            column_position: 0,
-            color_code: ColorCode::new(Color::Blue, Color::Magenta),
-            buffer: Box::leak(Box::new(buffer)),
-        }
-    }
-
-    fn construct_buffer() -> Buffer {
-        use array_init::array_init;
-
-        Buffer {
-            chars: array_init(|_| array_init(|_| Volatile::new(empty_char()))),
-        }
-    }
-
-    fn empty_char() -> ScreenChar {
-        ScreenChar {
-            ascii_character: b' ',
-            color_code: ColorCode::new(Color::Green, Color::Brown),
-        }
-    }
-
-    #[test]
-    fn write_byte() {
-        let mut writer = construct_writer();
-        writer.write_byte(b'X');
-        writer.write_byte(b'Y');
-
-        for (i, row) in writer.buffer.chars.iter().enumerate() {
-            for (j, screen_char) in row.iter().enumerate() {
-                let screen_char = screen_char.read();
-                if i == BUFFER_HEIGHT - 1 && j == 0 {
-                    assert_eq!(screen_char.ascii_character, b'X');
-                    assert_eq!(screen_char.color_code, writer.color_code);
-                } else if i == BUFFER_HEIGHT - 1 && j == 1 {
-                    assert_eq!(screen_char.ascii_character, b'Y');
-                    assert_eq!(screen_char.color_code, writer.color_code);
-                } else {
-                    assert_eq!(screen_char, empty_char());
-                }
-            }
-        }
-    }
-
-    #[test]
-    fn write_formatted() {
-        use core::fmt::Write;
-
-        let mut writer = construct_writer();
-        writeln!(&mut writer, "a").unwrap();
-        writeln!(&mut writer, "b{}", "c").unwrap();
-
-        for (i, row) in writer.buffer.chars.iter().enumerate() {
-            for (j, screen_char) in row.iter().enumerate() {
-                let screen_char = screen_char.read();
-                if i == BUFFER_HEIGHT - 3 && j == 0 {
-                    assert_eq!(screen_char.ascii_character, b'a');
-                    assert_eq!(screen_char.color_code, writer.color_code);
-                } else if i == BUFFER_HEIGHT - 2 && j == 0 {
-                    assert_eq!(screen_char.ascii_character, b'b');
-                    assert_eq!(screen_char.color_code, writer.color_code);
-                } else if i == BUFFER_HEIGHT - 2 && j == 1 {
-                    assert_eq!(screen_char.ascii_character, b'c');
-                    assert_eq!(screen_char.color_code, writer.color_code);
-                } else if i >= BUFFER_HEIGHT - 2 {
-                    assert_eq!(screen_char.ascii_character, b' ');
-                    assert_eq!(screen_char.color_code, writer.color_code);
-                } else {
-                    assert_eq!(screen_char, empty_char());
-                }
-            }
-        }
-    }
-}

From 0beb0d80f8e7667de82b0fed194bdac0128916e8 Mon Sep 17 00:00:00 2001
From: Philipp Oppermann <dev@phil-opp.com>
Date: Sat, 20 Apr 2019 18:29:43 +0200
Subject: [PATCH 07/27] Add a custom test runner

---
 src/main.rs | 14 ++++++++++++++
 1 file changed, 14 insertions(+)

diff --git a/src/main.rs b/src/main.rs
index 18e03650..d63dab29 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -1,5 +1,8 @@
 #![no_std]
 #![no_main]
+#![feature(custom_test_frameworks)]
+#![test_runner(crate::test_runner)]
+#![reexport_test_harness_main = "test_main"]
 
 use core::panic::PanicInfo;
 
@@ -9,9 +12,20 @@ mod vga_buffer;
 pub extern "C" fn _start() -> ! {
     println!("Hello World{}", "!");
 
+    #[cfg(test)]
+    test_main();
+
     loop {}
 }
 
+#[cfg(test)]
+fn test_runner(tests: &[&dyn Fn()]) {
+    println!("Running {} tests", tests.len());
+    for test in tests {
+        test();
+    }
+}
+
 /// This function is called on panic.
 #[panic_handler]
 fn panic(info: &PanicInfo) -> ! {

From 3aa6151729c19030ee947495f5d3d254d839f7e0 Mon Sep 17 00:00:00 2001
From: Philipp Oppermann <dev@phil-opp.com>
Date: Sat, 20 Apr 2019 18:30:34 +0200
Subject: [PATCH 08/27] Add a trivial_assertion test

---
 src/main.rs | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/src/main.rs b/src/main.rs
index d63dab29..f35b2fa4 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -32,3 +32,10 @@ fn panic(info: &PanicInfo) -> ! {
     println!("{}", info);
     loop {}
 }
+
+#[test_case]
+fn trivial_assertion() {
+    print!("trivial assertion... ");
+    assert_eq!(1, 1);
+    println!("[ok]");
+}

From dbdd46da9a770470ed565bfa56edfd65925f4262 Mon Sep 17 00:00:00 2001
From: Philipp Oppermann <dev@phil-opp.com>
Date: Sat, 20 Apr 2019 18:32:58 +0200
Subject: [PATCH 09/27] Exit qemu after running tests

---
 Cargo.lock  | 56 +++++++++++++++++++++++++++++++++++++++++++++++++++++
 Cargo.toml  |  2 ++
 src/main.rs | 15 ++++++++++++++
 3 files changed, 73 insertions(+)

diff --git a/Cargo.lock b/Cargo.lock
index f9be4ee3..ff21abbb 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -26,6 +26,7 @@ dependencies = [
  "lazy_static 1.3.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "spin 0.4.10 (registry+https://github.com/rust-lang/crates.io-index)",
  "volatile 0.2.6 (registry+https://github.com/rust-lang/crates.io-index)",
+ "x86_64 0.5.4 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
 [[package]]
@@ -41,6 +42,11 @@ dependencies = [
  "xmas-elf 0.6.2 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
+[[package]]
+name = "cc"
+version = "1.0.35"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+
 [[package]]
 name = "fixedvec"
 version = "0.2.3"
@@ -128,6 +134,16 @@ name = "rand_core"
 version = "0.4.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 
+[[package]]
+name = "raw-cpuid"
+version = "6.1.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "bitflags 1.0.4 (registry+https://github.com/rust-lang/crates.io-index)",
+ "cc 1.0.35 (registry+https://github.com/rust-lang/crates.io-index)",
+ "rustc_version 0.2.3 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
 [[package]]
 name = "rdrand"
 version = "0.4.0"
@@ -144,6 +160,27 @@ dependencies = [
  "winapi 0.3.7 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
+[[package]]
+name = "rustc_version"
+version = "0.2.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "semver 0.9.0 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
+[[package]]
+name = "semver"
+version = "0.9.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "semver-parser 0.7.0 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
+[[package]]
+name = "semver-parser"
+version = "0.7.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+
 [[package]]
 name = "skeptic"
 version = "0.5.0"
@@ -224,6 +261,19 @@ dependencies = [
  "ux 0.1.3 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
+[[package]]
+name = "x86_64"
+version = "0.5.4"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "array-init 0.0.4 (registry+https://github.com/rust-lang/crates.io-index)",
+ "bit_field 0.9.0 (registry+https://github.com/rust-lang/crates.io-index)",
+ "bitflags 1.0.4 (registry+https://github.com/rust-lang/crates.io-index)",
+ "raw-cpuid 6.1.0 (registry+https://github.com/rust-lang/crates.io-index)",
+ "usize_conversions 0.2.0 (registry+https://github.com/rust-lang/crates.io-index)",
+ "ux 0.1.3 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
 [[package]]
 name = "xmas-elf"
 version = "0.6.2"
@@ -242,6 +292,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 "checksum bit_field 0.9.0 (registry+https://github.com/rust-lang/crates.io-index)" = "ed8765909f9009617974ab6b7d332625b320b33c326b1e9321382ef1999b5d56"
 "checksum bitflags 1.0.4 (registry+https://github.com/rust-lang/crates.io-index)" = "228047a76f468627ca71776ecdebd732a3423081fcf5125585bcd7c49886ce12"
 "checksum bootloader 0.6.0 (registry+https://github.com/rust-lang/crates.io-index)" = "8654b1ebbd38d2a8687a451ad53466d01b5edc9d75ec63d676525a6103d77151"
+"checksum cc 1.0.35 (registry+https://github.com/rust-lang/crates.io-index)" = "5e5f3fee5eeb60324c2781f1e41286bdee933850fff9b3c672587fed5ec58c83"
 "checksum fixedvec 0.2.3 (registry+https://github.com/rust-lang/crates.io-index)" = "7c6c16d316ccdac21a4dd648e314e76facbbaf316e83ca137d0857a9c07419d0"
 "checksum font8x8 0.2.4 (registry+https://github.com/rust-lang/crates.io-index)" = "b81d84c3c978af7d05d31a2198af4b9ba956d819d15d8f6d58fc150e33f8dc1f"
 "checksum fuchsia-cprng 0.1.1 (registry+https://github.com/rust-lang/crates.io-index)" = "a06f77d526c1a601b7c4cdd98f54b5eaabffc14d5f2f0296febdc7f357c6d3ba"
@@ -255,8 +306,12 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 "checksum rand 0.4.6 (registry+https://github.com/rust-lang/crates.io-index)" = "552840b97013b1a26992c11eac34bdd778e464601a4c2054b5f0bff7c6761293"
 "checksum rand_core 0.3.1 (registry+https://github.com/rust-lang/crates.io-index)" = "7a6fdeb83b075e8266dcc8762c22776f6877a63111121f5f8c7411e5be7eed4b"
 "checksum rand_core 0.4.0 (registry+https://github.com/rust-lang/crates.io-index)" = "d0e7a549d590831370895ab7ba4ea0c1b6b011d106b5ff2da6eee112615e6dc0"
+"checksum raw-cpuid 6.1.0 (registry+https://github.com/rust-lang/crates.io-index)" = "30a9d219c32c9132f7be513c18be77c9881c7107d2ab5569d205a6a0f0e6dc7d"
 "checksum rdrand 0.4.0 (registry+https://github.com/rust-lang/crates.io-index)" = "678054eb77286b51581ba43620cc911abf02758c91f93f479767aed0f90458b2"
 "checksum remove_dir_all 0.5.1 (registry+https://github.com/rust-lang/crates.io-index)" = "3488ba1b9a2084d38645c4c08276a1752dcbf2c7130d74f1569681ad5d2799c5"
+"checksum rustc_version 0.2.3 (registry+https://github.com/rust-lang/crates.io-index)" = "138e3e0acb6c9fb258b19b67cb8abd63c00679d2851805ea151465464fe9030a"
+"checksum semver 0.9.0 (registry+https://github.com/rust-lang/crates.io-index)" = "1d7eb9ef2c18661902cc47e535f9bc51b78acd254da71d375c2f6720d9a40403"
+"checksum semver-parser 0.7.0 (registry+https://github.com/rust-lang/crates.io-index)" = "388a1df253eca08550bef6c72392cfe7c30914bf41df5269b68cbd6ff8f570a3"
 "checksum skeptic 0.5.0 (registry+https://github.com/rust-lang/crates.io-index)" = "061203a849117b0f7090baf8157aa91dac30545208fbb85166ac58b4ca33d89c"
 "checksum spin 0.4.10 (registry+https://github.com/rust-lang/crates.io-index)" = "ceac490aa12c567115b40b7b7fceca03a6c9d53d5defea066123debc83c5dc1f"
 "checksum spin 0.5.0 (registry+https://github.com/rust-lang/crates.io-index)" = "44363f6f51401c34e7be73db0db371c04705d35efbe9f7d6082e03a921a32c55"
@@ -269,5 +324,6 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 "checksum winapi-i686-pc-windows-gnu 0.4.0 (registry+https://github.com/rust-lang/crates.io-index)" = "ac3b87c63620426dd9b991e5ce0329eff545bccbbb34f3be09ff6fb6ab51b7b6"
 "checksum winapi-x86_64-pc-windows-gnu 0.4.0 (registry+https://github.com/rust-lang/crates.io-index)" = "712e227841d057c1ee1cd2fb22fa7e5a5461ae8e48fa2ca79ec42cfc1931183f"
 "checksum x86_64 0.3.6 (registry+https://github.com/rust-lang/crates.io-index)" = "f9258d7e2dd25008d69e8c9e9ee37865887a5e1e3d06a62f1cb3f6c209e6f177"
+"checksum x86_64 0.5.4 (registry+https://github.com/rust-lang/crates.io-index)" = "1d0a8201f52d2c7b373c7243dcdfb27c0dd5012f221ef6a126f507ee82005204"
 "checksum xmas-elf 0.6.2 (registry+https://github.com/rust-lang/crates.io-index)" = "22678df5df766e8d1e5d609da69f0c3132d794edf6ab5e75e7abcd2270d4cf58"
 "checksum zero 0.1.2 (registry+https://github.com/rust-lang/crates.io-index)" = "5f1bc8a6b2005884962297587045002d8cfb8dcec9db332f4ca216ddc5de82c5"
diff --git a/Cargo.toml b/Cargo.toml
index 43d26d71..86fb1bd3 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -8,6 +8,7 @@ edition = "2018"
 bootloader = "0.6.0"
 volatile = "0.2.3"
 spin = "0.4.9"
+x86_64 = "0.5.2"
 
 [dependencies.lazy_static]
 version = "1.0"
@@ -21,3 +22,4 @@ panic = "abort"
 
 [package.metadata.bootimage]
 default-target = "x86_64-blog_os.json"
+test-args = ["-device", "isa-debug-exit,iobase=0xf4,iosize=0x04"]
diff --git a/src/main.rs b/src/main.rs
index f35b2fa4..7180308a 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -24,6 +24,7 @@ fn test_runner(tests: &[&dyn Fn()]) {
     for test in tests {
         test();
     }
+    unsafe { exit_qemu(QemuExitCode::Success) };
 }
 
 /// This function is called on panic.
@@ -33,6 +34,20 @@ fn panic(info: &PanicInfo) -> ! {
     loop {}
 }
 
+#[derive(Debug, Clone, Copy, PartialEq, Eq)]
+#[repr(u32)]
+pub enum QemuExitCode {
+    Success = 0x10,
+    Failed = 0x11,
+}
+
+pub unsafe fn exit_qemu(exit_code: QemuExitCode) {
+    use x86_64::instructions::port::Port;
+
+    let mut port = Port::new(0xf4);
+    port.write(exit_code as u32);
+}
+
 #[test_case]
 fn trivial_assertion() {
     print!("trivial assertion... ");

From 98a0e605be80017866ab694cb083dab7387b8ee0 Mon Sep 17 00:00:00 2001
From: Philipp Oppermann <dev@phil-opp.com>
Date: Sat, 20 Apr 2019 18:34:30 +0200
Subject: [PATCH 10/27] Interpret exit code 33 as test success

---
 Cargo.toml | 1 +
 1 file changed, 1 insertion(+)

diff --git a/Cargo.toml b/Cargo.toml
index 86fb1bd3..4e17de9a 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -23,3 +23,4 @@ panic = "abort"
 [package.metadata.bootimage]
 default-target = "x86_64-blog_os.json"
 test-args = ["-device", "isa-debug-exit,iobase=0xf4,iosize=0x04"]
+test-success-exit-code = 33         # (0x10 << 1) | 1

From 155949380275ebd0f018436ea3caca3846ab0837 Mon Sep 17 00:00:00 2001
From: Philipp Oppermann <dev@phil-opp.com>
Date: Sat, 20 Apr 2019 18:40:25 +0200
Subject: [PATCH 11/27] Print test results over serial port

---
 Cargo.lock    | 11 +++++++++++
 Cargo.toml    |  5 ++++-
 src/main.rs   |  7 ++++---
 src/serial.rs | 37 +++++++++++++++++++++++++++++++++++++
 4 files changed, 56 insertions(+), 4 deletions(-)
 create mode 100644 src/serial.rs

diff --git a/Cargo.lock b/Cargo.lock
index ff21abbb..370d630a 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -25,6 +25,7 @@ dependencies = [
  "bootloader 0.6.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "lazy_static 1.3.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "spin 0.4.10 (registry+https://github.com/rust-lang/crates.io-index)",
+ "uart_16550 0.2.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "volatile 0.2.6 (registry+https://github.com/rust-lang/crates.io-index)",
  "x86_64 0.5.4 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
@@ -209,6 +210,15 @@ dependencies = [
  "remove_dir_all 0.5.1 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
+[[package]]
+name = "uart_16550"
+version = "0.2.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "bitflags 1.0.4 (registry+https://github.com/rust-lang/crates.io-index)",
+ "x86_64 0.5.4 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
 [[package]]
 name = "unicode-width"
 version = "0.1.5"
@@ -316,6 +326,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 "checksum spin 0.4.10 (registry+https://github.com/rust-lang/crates.io-index)" = "ceac490aa12c567115b40b7b7fceca03a6c9d53d5defea066123debc83c5dc1f"
 "checksum spin 0.5.0 (registry+https://github.com/rust-lang/crates.io-index)" = "44363f6f51401c34e7be73db0db371c04705d35efbe9f7d6082e03a921a32c55"
 "checksum tempdir 0.3.7 (registry+https://github.com/rust-lang/crates.io-index)" = "15f2b5fb00ccdf689e0149d1b1b3c03fead81c2b37735d812fa8bddbbf41b6d8"
+"checksum uart_16550 0.2.0 (registry+https://github.com/rust-lang/crates.io-index)" = "5b9392f60931fe3bf8f24e0a15ee4f51528770f1d64c48768ab66571334d95b0"
 "checksum unicode-width 0.1.5 (registry+https://github.com/rust-lang/crates.io-index)" = "882386231c45df4700b275c7ff55b6f3698780a650026380e72dabe76fa46526"
 "checksum usize_conversions 0.2.0 (registry+https://github.com/rust-lang/crates.io-index)" = "f70329e2cbe45d6c97a5112daad40c34cd9a4e18edb5a2a18fefeb584d8d25e5"
 "checksum ux 0.1.3 (registry+https://github.com/rust-lang/crates.io-index)" = "88dfeb711b61ce620c0cb6fd9f8e3e678622f0c971da2a63c4b3e25e88ed012f"
diff --git a/Cargo.toml b/Cargo.toml
index 4e17de9a..c5987010 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -9,6 +9,7 @@ bootloader = "0.6.0"
 volatile = "0.2.3"
 spin = "0.4.9"
 x86_64 = "0.5.2"
+uart_16550 = "0.2.0"
 
 [dependencies.lazy_static]
 version = "1.0"
@@ -22,5 +23,7 @@ panic = "abort"
 
 [package.metadata.bootimage]
 default-target = "x86_64-blog_os.json"
-test-args = ["-device", "isa-debug-exit,iobase=0xf4,iosize=0x04"]
+test-args = [
+    "-device", "isa-debug-exit,iobase=0xf4,iosize=0x04", "-serial", "mon:stdio"
+]
 test-success-exit-code = 33         # (0x10 << 1) | 1
diff --git a/src/main.rs b/src/main.rs
index 7180308a..4798dec4 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -6,6 +6,7 @@
 
 use core::panic::PanicInfo;
 
+mod serial;
 mod vga_buffer;
 
 #[no_mangle]
@@ -20,7 +21,7 @@ pub extern "C" fn _start() -> ! {
 
 #[cfg(test)]
 fn test_runner(tests: &[&dyn Fn()]) {
-    println!("Running {} tests", tests.len());
+    serial_println!("Running {} tests", tests.len());
     for test in tests {
         test();
     }
@@ -50,7 +51,7 @@ pub unsafe fn exit_qemu(exit_code: QemuExitCode) {
 
 #[test_case]
 fn trivial_assertion() {
-    print!("trivial assertion... ");
+    serial_print!("trivial assertion... ");
     assert_eq!(1, 1);
-    println!("[ok]");
+    serial_println!("[ok]");
 }
diff --git a/src/serial.rs b/src/serial.rs
new file mode 100644
index 00000000..e8807df8
--- /dev/null
+++ b/src/serial.rs
@@ -0,0 +1,37 @@
+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;
+    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)*));
+}

From 3ecf9a9b565040435ba4a8435d114af3ed4bdccb Mon Sep 17 00:00:00 2001
From: Philipp Oppermann <dev@phil-opp.com>
Date: Sat, 20 Apr 2019 18:50:43 +0200
Subject: [PATCH 12/27] Exit qemu on panic

---
 src/main.rs | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/src/main.rs b/src/main.rs
index 4798dec4..f8e09cbd 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -29,12 +29,22 @@ fn test_runner(tests: &[&dyn Fn()]) {
 }
 
 /// This function is called on panic.
+#[cfg(not(test))]
 #[panic_handler]
 fn panic(info: &PanicInfo) -> ! {
     println!("{}", info);
     loop {}
 }
 
+#[cfg(test)]
+#[panic_handler]
+fn panic(info: &PanicInfo) -> ! {
+    serial_println!("[failed]\n");
+    serial_println!("Error: {}\n", info);
+    unsafe { exit_qemu(QemuExitCode::Failed); }
+    loop {}
+}
+
 #[derive(Debug, Clone, Copy, PartialEq, Eq)]
 #[repr(u32)]
 pub enum QemuExitCode {

From d4ebbc291a29210319c3a69931ec90b298ca99d4 Mon Sep 17 00:00:00 2001
From: Philipp Oppermann <dev@phil-opp.com>
Date: Sat, 20 Apr 2019 18:51:37 +0200
Subject: [PATCH 13/27] Hide QEMU in test mode

---
 Cargo.toml | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/Cargo.toml b/Cargo.toml
index c5987010..554e3482 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -24,6 +24,7 @@ panic = "abort"
 [package.metadata.bootimage]
 default-target = "x86_64-blog_os.json"
 test-args = [
-    "-device", "isa-debug-exit,iobase=0xf4,iosize=0x04", "-serial", "mon:stdio"
+    "-device", "isa-debug-exit,iobase=0xf4,iosize=0x04", "-serial", "mon:stdio",
+    "-display", "none"
 ]
 test-success-exit-code = 33         # (0x10 << 1) | 1

From 4cbac20b40594d34d1c06773dbe50d8e2d7414df Mon Sep 17 00:00:00 2001
From: Philipp Oppermann <dev@phil-opp.com>
Date: Sat, 20 Apr 2019 19:04:55 +0200
Subject: [PATCH 14/27] Add tests for the VGA buffer

---
 src/main.rs       |  7 -------
 src/vga_buffer.rs | 31 +++++++++++++++++++++++++++++++
 2 files changed, 31 insertions(+), 7 deletions(-)

diff --git a/src/main.rs b/src/main.rs
index f8e09cbd..c715b7ca 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -58,10 +58,3 @@ pub unsafe fn exit_qemu(exit_code: QemuExitCode) {
     let mut port = Port::new(0xf4);
     port.write(exit_code as u32);
 }
-
-#[test_case]
-fn trivial_assertion() {
-    serial_print!("trivial assertion... ");
-    assert_eq!(1, 1);
-    serial_println!("[ok]");
-}
diff --git a/src/vga_buffer.rs b/src/vga_buffer.rs
index 94dbc4c6..e7d4ed5f 100644
--- a/src/vga_buffer.rs
+++ b/src/vga_buffer.rs
@@ -2,6 +2,7 @@ use core::fmt;
 use lazy_static::lazy_static;
 use spin::Mutex;
 use volatile::Volatile;
+use crate::{serial_print, serial_println};
 
 lazy_static! {
     /// A global `Writer` instance that can be used for printing to the VGA text buffer.
@@ -169,3 +170,33 @@ pub fn _print(args: fmt::Arguments) {
     use core::fmt::Write;
     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() {
+    serial_print!("test_println_output... ");
+
+    let s = "Some test string that fits on a single line";
+    println!("{}", s);
+    for (i, c) in s.chars().enumerate() {
+        let screen_char = WRITER.lock().buffer.chars[BUFFER_HEIGHT - 2][i].read();
+        assert_eq!(char::from(screen_char.ascii_character), c);
+    }
+
+    serial_println!("[ok]");
+}

From 46bb44b95d066bd73505613396042e759bc3769b Mon Sep 17 00:00:00 2001
From: Philipp Oppermann <dev@phil-opp.com>
Date: Sat, 20 Apr 2019 19:06:00 +0200
Subject: [PATCH 15/27] Run cargo fmt

---
 src/main.rs       | 4 +++-
 src/vga_buffer.rs | 2 +-
 2 files changed, 4 insertions(+), 2 deletions(-)

diff --git a/src/main.rs b/src/main.rs
index c715b7ca..e76ebb8e 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -41,7 +41,9 @@ fn panic(info: &PanicInfo) -> ! {
 fn panic(info: &PanicInfo) -> ! {
     serial_println!("[failed]\n");
     serial_println!("Error: {}\n", info);
-    unsafe { exit_qemu(QemuExitCode::Failed); }
+    unsafe {
+        exit_qemu(QemuExitCode::Failed);
+    }
     loop {}
 }
 
diff --git a/src/vga_buffer.rs b/src/vga_buffer.rs
index e7d4ed5f..d53fcbe4 100644
--- a/src/vga_buffer.rs
+++ b/src/vga_buffer.rs
@@ -1,8 +1,8 @@
+use crate::{serial_print, serial_println};
 use core::fmt;
 use lazy_static::lazy_static;
 use spin::Mutex;
 use volatile::Volatile;
-use crate::{serial_print, serial_println};
 
 lazy_static! {
     /// A global `Writer` instance that can be used for printing to the VGA text buffer.

From d0629ba5a22ac71f14e3e2f87a5b623f9e129311 Mon Sep 17 00:00:00 2001
From: Philipp Oppermann <dev@phil-opp.com>
Date: Mon, 22 Apr 2019 11:48:50 +0200
Subject: [PATCH 16/27] Import serial_println only in test mode

---
 src/vga_buffer.rs | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/src/vga_buffer.rs b/src/vga_buffer.rs
index d53fcbe4..fcf95893 100644
--- a/src/vga_buffer.rs
+++ b/src/vga_buffer.rs
@@ -1,9 +1,11 @@
-use crate::{serial_print, serial_println};
 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.
     ///

From 3b13211579fcd1f195f7a1acda3b71f862bc50ae Mon Sep 17 00:00:00 2001
From: Philipp Oppermann <dev@phil-opp.com>
Date: Mon, 22 Apr 2019 11:52:22 +0200
Subject: [PATCH 17/27] Add the skeleton for an integration test

---
 tests/basic_boot.rs | 23 +++++++++++++++++++++++
 1 file changed, 23 insertions(+)
 create mode 100644 tests/basic_boot.rs

diff --git a/tests/basic_boot.rs b/tests/basic_boot.rs
new file mode 100644
index 00000000..52ff9810
--- /dev/null
+++ b/tests/basic_boot.rs
@@ -0,0 +1,23 @@
+#![no_std]
+#![no_main]
+#![feature(custom_test_frameworks)]
+#![test_runner(crate::test_runner)]
+#![reexport_test_harness_main = "test_main"]
+
+use core::panic::PanicInfo;
+
+#[no_mangle] // don't mangle the name of this function
+pub extern "C" fn _start() -> ! {
+    test_main();
+
+    loop {}
+}
+
+fn test_runner(tests: &[&dyn Fn()]) {
+    unimplemented!();
+}
+
+#[panic_handler]
+fn panic(info: &PanicInfo) -> ! {
+    loop {}
+}

From 48e1f72d2390d7dd9a2556ca15a8f49f4862bd9c Mon Sep 17 00:00:00 2001
From: Philipp Oppermann <dev@phil-opp.com>
Date: Mon, 22 Apr 2019 12:06:16 +0200
Subject: [PATCH 18/27] Split off a library

---
 src/lib.rs  | 55 +++++++++++++++++++++++++++++++++++++++++++++++++++++
 src/main.rs | 36 +++--------------------------------
 2 files changed, 58 insertions(+), 33 deletions(-)
 create mode 100644 src/lib.rs

diff --git a/src/lib.rs b/src/lib.rs
new file mode 100644
index 00000000..96db9bcb
--- /dev/null
+++ b/src/lib.rs
@@ -0,0 +1,55 @@
+#![no_std]
+#![cfg_attr(test, no_main)]
+#![feature(custom_test_frameworks)]
+#![test_runner(crate::test_runner)]
+#![reexport_test_harness_main = "test_main"]
+
+use core::panic::PanicInfo;
+
+pub mod serial;
+pub mod vga_buffer;
+
+pub fn test_runner(tests: &[&dyn Fn()]) {
+    serial_println!("Running {} tests", tests.len());
+    for test in tests {
+        test();
+    }
+    unsafe { exit_qemu(QemuExitCode::Success) };
+}
+
+pub fn test_panic_handler(info: &PanicInfo) -> ! {
+    serial_println!("[failed]\n");
+    serial_println!("Error: {}\n", info);
+    unsafe {
+        exit_qemu(QemuExitCode::Failed);
+    }
+    loop {}
+}
+
+#[derive(Debug, Clone, Copy, PartialEq, Eq)]
+#[repr(u32)]
+pub enum QemuExitCode {
+    Success = 0x10,
+    Failed = 0x11,
+}
+
+pub unsafe fn exit_qemu(exit_code: QemuExitCode) {
+    use x86_64::instructions::port::Port;
+
+    let mut port = Port::new(0xf4);
+    port.write(exit_code as u32);
+}
+
+/// Entry point for `cargo xtest`
+#[cfg(test)]
+#[no_mangle]
+pub extern "C" fn _start() -> ! {
+    test_main();
+    loop {}
+}
+
+#[cfg(test)]
+#[panic_handler]
+fn panic(info: &PanicInfo) -> ! {
+    test_panic_handler(info)
+}
diff --git a/src/main.rs b/src/main.rs
index e76ebb8e..6e7f82d2 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -1,14 +1,12 @@
 #![no_std]
 #![no_main]
 #![feature(custom_test_frameworks)]
-#![test_runner(crate::test_runner)]
+#![test_runner(blog_os::test_runner)]
 #![reexport_test_harness_main = "test_main"]
 
+use blog_os::println;
 use core::panic::PanicInfo;
 
-mod serial;
-mod vga_buffer;
-
 #[no_mangle]
 pub extern "C" fn _start() -> ! {
     println!("Hello World{}", "!");
@@ -19,15 +17,6 @@ pub extern "C" fn _start() -> ! {
     loop {}
 }
 
-#[cfg(test)]
-fn test_runner(tests: &[&dyn Fn()]) {
-    serial_println!("Running {} tests", tests.len());
-    for test in tests {
-        test();
-    }
-    unsafe { exit_qemu(QemuExitCode::Success) };
-}
-
 /// This function is called on panic.
 #[cfg(not(test))]
 #[panic_handler]
@@ -39,24 +28,5 @@ fn panic(info: &PanicInfo) -> ! {
 #[cfg(test)]
 #[panic_handler]
 fn panic(info: &PanicInfo) -> ! {
-    serial_println!("[failed]\n");
-    serial_println!("Error: {}\n", info);
-    unsafe {
-        exit_qemu(QemuExitCode::Failed);
-    }
-    loop {}
-}
-
-#[derive(Debug, Clone, Copy, PartialEq, Eq)]
-#[repr(u32)]
-pub enum QemuExitCode {
-    Success = 0x10,
-    Failed = 0x11,
-}
-
-pub unsafe fn exit_qemu(exit_code: QemuExitCode) {
-    use x86_64::instructions::port::Port;
-
-    let mut port = Port::new(0xf4);
-    port.write(exit_code as u32);
+    blog_os::test_panic_handler(info)
 }

From a2d628cabe80af76a83b702a88cca20e2c52505d Mon Sep 17 00:00:00 2001
From: Philipp Oppermann <dev@phil-opp.com>
Date: Mon, 22 Apr 2019 13:20:22 +0200
Subject: [PATCH 19/27] Complete the basic_boot integration test

---
 tests/basic_boot.rs | 8 ++------
 1 file changed, 2 insertions(+), 6 deletions(-)

diff --git a/tests/basic_boot.rs b/tests/basic_boot.rs
index 52ff9810..d737b4da 100644
--- a/tests/basic_boot.rs
+++ b/tests/basic_boot.rs
@@ -1,7 +1,7 @@
 #![no_std]
 #![no_main]
 #![feature(custom_test_frameworks)]
-#![test_runner(crate::test_runner)]
+#![test_runner(blog_os::test_runner)]
 #![reexport_test_harness_main = "test_main"]
 
 use core::panic::PanicInfo;
@@ -13,11 +13,7 @@ pub extern "C" fn _start() -> ! {
     loop {}
 }
 
-fn test_runner(tests: &[&dyn Fn()]) {
-    unimplemented!();
-}
-
 #[panic_handler]
 fn panic(info: &PanicInfo) -> ! {
-    loop {}
+    blog_os::test_panic_handler(info)
 }

From cdd91df869ba54ae759374e8dbf28188e8044ba2 Mon Sep 17 00:00:00 2001
From: Philipp Oppermann <dev@phil-opp.com>
Date: Mon, 22 Apr 2019 13:25:09 +0200
Subject: [PATCH 20/27] Run cargo xtest on CI

---
 .appveyor.yml       | 1 +
 .travis.yml         | 1 +
 azure-pipelines.yml | 3 +++
 3 files changed, 5 insertions(+)

diff --git a/.appveyor.yml b/.appveyor.yml
index 423cc6db..e2d5851d 100644
--- a/.appveyor.yml
+++ b/.appveyor.yml
@@ -75,3 +75,4 @@ before_test:
 test_script:
   - cargo xbuild
   - cargo bootimage
+  - cargo xtest
diff --git a/.travis.yml b/.travis.yml
index 1e6697ca..b2daef83 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -35,4 +35,5 @@ before_script:
 script:
   - cargo xbuild
   - cargo bootimage
+  - cargo xtest
   - cargo cache --autoclean
diff --git a/azure-pipelines.yml b/azure-pipelines.yml
index 672a9add..9c81050f 100644
--- a/azure-pipelines.yml
+++ b/azure-pipelines.yml
@@ -61,6 +61,9 @@ steps:
 - script: cargo bootimage
   displayName: 'Create Bootimage'
 
+- script: cargo xtest
+  displayName: 'Test'
+
 - script: rustup component add rustfmt
   displayName: 'Install Rustfmt'
 

From c2f36e086e9efb1ef3c4161fafe54b6073fc9480 Mon Sep 17 00:00:00 2001
From: Philipp Oppermann <dev@phil-opp.com>
Date: Mon, 22 Apr 2019 14:09:20 +0200
Subject: [PATCH 21/27] Install qemu on CI

---
 .appveyor.yml       | 11 +++++++++++
 .travis.yml         | 11 +++++++++++
 azure-pipelines.yml | 20 ++++++++++++++++++++
 3 files changed, 42 insertions(+)

diff --git a/.appveyor.yml b/.appveyor.yml
index e2d5851d..71c10ea7 100644
--- a/.appveyor.yml
+++ b/.appveyor.yml
@@ -55,6 +55,17 @@ install:
   - set PATH=%PATH%;%USERPROFILE%\.cargo\bin
   - rustc -vV
   - cargo -vV
+    # Install qemu
+  - echo %cd%
+  - mkdir "C:\Program Files\qemu"
+  - cd "C:\Program Files\qemu"
+  - if %target%==i686-pc-windows-msvc appveyor DownloadFile "https://qemu.weilnetz.de/w32/2018/qemu-w32-setup-20180801.exe" -FileName "qemu-setup.exe"
+  - if %target%==i686-pc-windows-gnu appveyor DownloadFile "https://qemu.weilnetz.de/w32/2018/qemu-w32-setup-20180801.exe" -FileName "qemu-setup.exe"
+  - if %target%==x86_64-pc-windows-msvc appveyor DownloadFile "https://qemu.weilnetz.de/w64/2018/qemu-w64-setup-20180801.exe" -FileName "qemu-setup.exe"
+  - if %target%==x86_64-pc-windows-gnu appveyor DownloadFile "https://qemu.weilnetz.de/w64/2018/qemu-w64-setup-20180801.exe" -FileName "qemu-setup.exe"
+  - 7z x qemu-setup.exe
+  - set PATH=%PATH%;C:\Program Files\qemu
+  - cd "C:\projects\blog-os"
 
 ## Build Script ##
 
diff --git a/.travis.yml b/.travis.yml
index b2daef83..0d1ba227 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -28,6 +28,17 @@ cache:
   directories:
     - $HOME/.cargo
 
+addons:
+  apt:
+    packages:
+      - qemu-system-x86
+  homebrew:
+    packages:
+      - qemu
+
+install:
+  - if [ $TRAVIS_OS_NAME = windows ]; then choco install qemu; export PATH="/c/Program Files/qemu:$PATH"; fi
+
 before_script:
   - rustup component add rust-src llvm-tools-preview
   - cargo install cargo-xbuild bootimage cargo-cache --debug -Z install-upgrade
diff --git a/azure-pipelines.yml b/azure-pipelines.yml
index 9c81050f..577b7e35 100644
--- a/azure-pipelines.yml
+++ b/azure-pipelines.yml
@@ -61,6 +61,26 @@ steps:
 - script: cargo bootimage
   displayName: 'Create Bootimage'
 
+- script: sudo apt update && sudo apt install qemu-system-x86
+  condition: eq( variables['Agent.OS'], 'Linux' )
+  displayName: 'Install QEMU (Linux)'
+
+- script: |
+    export HOMEBREW_NO_AUTO_UPDATE=1
+    export HOMEBREW_NO_BOTTLE_SOURCE_FALLBACK=1
+    export HOMEBREW_NO_INSTALL_CLEANUP=1
+    brew install qemu
+  condition: eq( variables['Agent.OS'], 'Darwin' )
+  displayName: 'Install QEMU (macOS)'
+
+- script: |
+    choco install qemu --limit-output --no-progress
+    echo ##vso[task.setvariable variable=PATH;]%PATH%;C:\Program Files\qemu
+    set PATH=%PATH%;C:\Program Files\qemu
+    qemu-system-x86_64 --version
+  condition: eq( variables['Agent.OS'], 'Windows_NT' )
+  displayName: 'Install QEMU (Windows)'
+
 - script: cargo xtest
   displayName: 'Test'
 

From 2e5f192f35d1c7896c33849374d5d865c541db7d Mon Sep 17 00:00:00 2001
From: Philipp Oppermann <dev@phil-opp.com>
Date: Tue, 23 Apr 2019 16:50:07 +0200
Subject: [PATCH 22/27] Make exit_qemu safe

---
 src/lib.rs | 14 +++++++-------
 1 file changed, 7 insertions(+), 7 deletions(-)

diff --git a/src/lib.rs b/src/lib.rs
index 96db9bcb..83169fe7 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -14,15 +14,13 @@ pub fn test_runner(tests: &[&dyn Fn()]) {
     for test in tests {
         test();
     }
-    unsafe { exit_qemu(QemuExitCode::Success) };
+    exit_qemu(QemuExitCode::Success);
 }
 
 pub fn test_panic_handler(info: &PanicInfo) -> ! {
     serial_println!("[failed]\n");
     serial_println!("Error: {}\n", info);
-    unsafe {
-        exit_qemu(QemuExitCode::Failed);
-    }
+    exit_qemu(QemuExitCode::Failed);
     loop {}
 }
 
@@ -33,11 +31,13 @@ pub enum QemuExitCode {
     Failed = 0x11,
 }
 
-pub unsafe fn exit_qemu(exit_code: QemuExitCode) {
+pub fn exit_qemu(exit_code: QemuExitCode) {
     use x86_64::instructions::port::Port;
 
-    let mut port = Port::new(0xf4);
-    port.write(exit_code as u32);
+    unsafe {
+        let mut port = Port::new(0xf4);
+        port.write(exit_code as u32);
+    }
 }
 
 /// Entry point for `cargo xtest`

From a55ced6b7f22f21686e9ded2aa9fd7f1c39e31c7 Mon Sep 17 00:00:00 2001
From: Philipp Oppermann <dev@phil-opp.com>
Date: Tue, 23 Apr 2019 16:50:19 +0200
Subject: [PATCH 23/27] Add a basic test to basic_boot

---
 tests/basic_boot.rs | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/tests/basic_boot.rs b/tests/basic_boot.rs
index d737b4da..eb4a25ed 100644
--- a/tests/basic_boot.rs
+++ b/tests/basic_boot.rs
@@ -5,6 +5,7 @@
 #![reexport_test_harness_main = "test_main"]
 
 use core::panic::PanicInfo;
+use blog_os::{println, serial_print, serial_println};
 
 #[no_mangle] // don't mangle the name of this function
 pub extern "C" fn _start() -> ! {
@@ -17,3 +18,10 @@ pub extern "C" fn _start() -> ! {
 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]");
+}

From ccb8b79ef81b986dae51dd5e2c2976e34b374187 Mon Sep 17 00:00:00 2001
From: Philipp Oppermann <dev@phil-opp.com>
Date: Tue, 23 Apr 2019 16:50:32 +0200
Subject: [PATCH 24/27] Add a panic handler test

---
 Cargo.toml             |  4 +++
 tests/panic_handler.rs | 69 ++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 73 insertions(+)
 create mode 100644 tests/panic_handler.rs

diff --git a/Cargo.toml b/Cargo.toml
index 554e3482..d984b6ae 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -4,6 +4,10 @@ version = "0.1.0"
 authors = ["Philipp Oppermann <dev@phil-opp.com>"]
 edition = "2018"
 
+[[test]]
+name = "panic_handler"
+harness = false
+
 [dependencies]
 bootloader = "0.6.0"
 volatile = "0.2.3"
diff --git a/tests/panic_handler.rs b/tests/panic_handler.rs
new file mode 100644
index 00000000..c15df7d3
--- /dev/null
+++ b/tests/panic_handler.rs
@@ -0,0 +1,69 @@
+#![no_std]
+#![no_main]
+#![feature(panic_info_message)]
+
+use core::{fmt::{self, Write}, panic::PanicInfo};
+use blog_os::{serial_print, serial_println, QemuExitCode, exit_qemu};
+
+const MESSAGE: &str = "Example panic message from panic_handler test";
+const PANIC_LINE: u32 = 14; // adjust this when moving the `panic!` call
+
+#[no_mangle]
+pub extern "C" fn _start() -> ! {
+    serial_print!("panic_handler... ");
+    panic!(MESSAGE); // must be in line `PANIC_LINE` 
+}
+
+#[panic_handler]
+fn panic(info: &PanicInfo) -> ! {   
+    check_location(info);
+    check_message(info);
+
+    serial_println!("[ok]");
+    exit_qemu(QemuExitCode::Success);
+    loop {}
+}
+
+fn fail(error: &str) -> ! {
+    serial_println!("[failed]");
+    serial_println!("{}", error);
+    exit_qemu(QemuExitCode::Failed);
+    loop {}
+}
+
+fn check_location(info: &PanicInfo) {
+    let location = info.location().unwrap_or_else(|| fail("no location"));
+    if location.file() != file!() {
+        fail("file name wrong");
+    }
+    if location.line() != PANIC_LINE {
+        fail("file line wrong");
+    }
+}
+
+fn check_message(info: &PanicInfo) {
+    let message = info.message().unwrap_or_else(|| fail("no message"));
+    let mut compare_message = CompareMessage { equals: false };
+    write!(&mut compare_message, "{}", message).unwrap_or_else(|_| fail("write failed"));
+    if !compare_message.equals {
+        fail("message not equal to expected message");
+    }
+}
+
+/// Compares a `fmt::Arguments` instance with the `MESSAGE` string
+/// 
+/// To use this type, write the `fmt::Arguments` instance to it using the
+/// `write` macro. If a message component matches `MESSAGE`, the equals
+/// field is set to true.
+struct CompareMessage {
+    equals: bool,
+}
+
+impl fmt::Write for CompareMessage {
+    fn write_str(&mut self, s: &str) -> fmt::Result {
+        if s == MESSAGE {
+            self.equals = true;
+        }
+        Ok(())
+    }
+}
\ No newline at end of file

From c8087cdd6f2c11c21a4acc1350482c1e8d505202 Mon Sep 17 00:00:00 2001
From: Philipp Oppermann <dev@phil-opp.com>
Date: Thu, 25 Apr 2019 12:23:45 +0200
Subject: [PATCH 25/27] Update Readme for `Testing` post

---
 README.md | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/README.md b/README.md
index 216c9bcc..9392cf06 100644
--- a/README.md
+++ b/README.md
@@ -1,10 +1,10 @@
-# Blog OS (Unit Testing)
+# Blog OS (Testing)
 
 [![Azure Pipelines CI build](https://img.shields.io/azure-devops/build/phil-opp/blog_os/1/post-04.svg?label=Build&style=flat-square)](https://dev.azure.com/phil-opp/blog_os/_build?definitionId=1)
 
-This repository contains the source code for the [Unit Testing][post] post of the [Writing an OS in Rust](https://os.phil-opp.com) series.
+This repository contains the source code for the [Testing][post] post of the [Writing an OS in Rust](https://os.phil-opp.com) series.
 
-[post]: https://os.phil-opp.com/unit-testing/
+[post]: https://os.phil-opp.com/testing/
 
 **Check out the [master branch](https://github.com/phil-opp/blog_os) for more information.**
 
@@ -54,7 +54,7 @@ Where `sdX` is the device name of your USB stick. **Be careful** to choose the c
 
 ## Testing
 
-To run the unit tests on the host system, execute `cargo test`.
+To run the unit and integration tests, execute `cargo xtest`.
 
 ## License
 The source code is dual-licensed under MIT or the Apache License (Version 2.0).

From 8374aa6ab6d9c0238d767ea37c8cf68cac7e0e06 Mon Sep 17 00:00:00 2001
From: Philipp Oppermann <dev@phil-opp.com>
Date: Thu, 25 Apr 2019 18:10:59 +0200
Subject: [PATCH 26/27] Run cargo fmt

---
 tests/basic_boot.rs    |  2 +-
 tests/panic_handler.rs | 15 +++++++++------
 2 files changed, 10 insertions(+), 7 deletions(-)

diff --git a/tests/basic_boot.rs b/tests/basic_boot.rs
index eb4a25ed..f5cf85e5 100644
--- a/tests/basic_boot.rs
+++ b/tests/basic_boot.rs
@@ -4,8 +4,8 @@
 #![test_runner(blog_os::test_runner)]
 #![reexport_test_harness_main = "test_main"]
 
-use core::panic::PanicInfo;
 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() -> ! {
diff --git a/tests/panic_handler.rs b/tests/panic_handler.rs
index c15df7d3..0e1e6819 100644
--- a/tests/panic_handler.rs
+++ b/tests/panic_handler.rs
@@ -2,8 +2,11 @@
 #![no_main]
 #![feature(panic_info_message)]
 
-use core::{fmt::{self, Write}, panic::PanicInfo};
-use blog_os::{serial_print, serial_println, QemuExitCode, exit_qemu};
+use blog_os::{exit_qemu, serial_print, serial_println, QemuExitCode};
+use core::{
+    fmt::{self, Write},
+    panic::PanicInfo,
+};
 
 const MESSAGE: &str = "Example panic message from panic_handler test";
 const PANIC_LINE: u32 = 14; // adjust this when moving the `panic!` call
@@ -11,11 +14,11 @@ const PANIC_LINE: u32 = 14; // adjust this when moving the `panic!` call
 #[no_mangle]
 pub extern "C" fn _start() -> ! {
     serial_print!("panic_handler... ");
-    panic!(MESSAGE); // must be in line `PANIC_LINE` 
+    panic!(MESSAGE); // must be in line `PANIC_LINE`
 }
 
 #[panic_handler]
-fn panic(info: &PanicInfo) -> ! {   
+fn panic(info: &PanicInfo) -> ! {
     check_location(info);
     check_message(info);
 
@@ -51,7 +54,7 @@ fn check_message(info: &PanicInfo) {
 }
 
 /// Compares a `fmt::Arguments` instance with the `MESSAGE` string
-/// 
+///
 /// To use this type, write the `fmt::Arguments` instance to it using the
 /// `write` macro. If a message component matches `MESSAGE`, the equals
 /// field is set to true.
@@ -66,4 +69,4 @@ impl fmt::Write for CompareMessage {
         }
         Ok(())
     }
-}
\ No newline at end of file
+}

From ad99afae988fba54411ad7130d28946a02188c78 Mon Sep 17 00:00:00 2001
From: Philipp Oppermann <dev@phil-opp.com>
Date: Thu, 25 Apr 2019 18:18:39 +0200
Subject: [PATCH 27/27] Fix panic_handler test by fixing line number

---
 tests/panic_handler.rs | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/tests/panic_handler.rs b/tests/panic_handler.rs
index 0e1e6819..5a55537c 100644
--- a/tests/panic_handler.rs
+++ b/tests/panic_handler.rs
@@ -9,7 +9,7 @@ use core::{
 };
 
 const MESSAGE: &str = "Example panic message from panic_handler test";
-const PANIC_LINE: u32 = 14; // adjust this when moving the `panic!` call
+const PANIC_LINE: u32 = 17; // adjust this when moving the `panic!` call
 
 #[no_mangle]
 pub extern "C" fn _start() -> ! {