From 3ce65d65908715552c68af63f74927ead3bb82d1 Mon Sep 17 00:00:00 2001
From: Philipp Oppermann <dev@phil-opp.com>
Date: Fri, 17 Jul 2020 08:49:49 +0200
Subject: [PATCH 01/10] Build with `cargo build` instead of `xbuild` if rlibc
 is a dependencyy

---
 src/builder/mod.rs | 35 ++++++++++++++++++++++++-----------
 1 file changed, 24 insertions(+), 11 deletions(-)

diff --git a/src/builder/mod.rs b/src/builder/mod.rs
index 86afea6..3687c12 100644
--- a/src/builder/mod.rs
+++ b/src/builder/mod.rs
@@ -44,7 +44,7 @@ impl Builder {
     ///
     /// If the quiet argument is set to true, all output to stdout is suppressed.
     pub fn build_kernel(
-        &self,
+        &mut self,
         args: &[String],
         quiet: bool,
     ) -> Result<Vec<PathBuf>, BuildKernelError> {
@@ -52,10 +52,21 @@ impl Builder {
             println!("Building kernel");
         }
 
+        let build_arg = if self
+            .project_metadata()
+            .ok()
+            .and_then(|m| m.packages.iter().find(|p| p.name == "rlibc"))
+            .is_some()
+        {
+            "build"
+        } else {
+            "xbuild"
+        };
+
         // try to run cargo xbuild
         let cargo = std::env::var("CARGO").unwrap_or_else(|_| "cargo".to_owned());
         let mut cmd = process::Command::new(&cargo);
-        cmd.arg("xbuild");
+        cmd.arg(build_arg);
         cmd.args(args);
         if !quiet {
             cmd.stdout(process::Stdio::inherit());
@@ -66,14 +77,16 @@ impl Builder {
             error: err,
         })?;
         if !output.status.success() {
-            // try executing `cargo xbuild --help` to check whether cargo-xbuild is installed
-            let mut help_command = process::Command::new("cargo");
-            help_command.arg("xbuild").arg("--help");
-            help_command.stdout(process::Stdio::null());
-            help_command.stderr(process::Stdio::null());
-            if let Ok(help_exit_status) = help_command.status() {
-                if !help_exit_status.success() {
-                    return Err(BuildKernelError::XbuildNotFound);
+            if build_arg == "xbuild" {
+                // try executing `cargo xbuild --help` to check whether cargo-xbuild is installed
+                let mut help_command = process::Command::new("cargo");
+                help_command.arg("xbuild").arg("--help");
+                help_command.stdout(process::Stdio::null());
+                help_command.stderr(process::Stdio::null());
+                if let Ok(help_exit_status) = help_command.status() {
+                    if !help_exit_status.success() {
+                        return Err(BuildKernelError::XbuildNotFound);
+                    }
                 }
             }
             return Err(BuildKernelError::XbuildFailed {
@@ -83,7 +96,7 @@ impl Builder {
 
         // Retrieve binary paths
         let mut cmd = process::Command::new(cargo);
-        cmd.arg("xbuild");
+        cmd.arg(build_arg);
         cmd.args(args);
         cmd.arg("--message-format").arg("json");
         let output = cmd.output().map_err(|err| BuildKernelError::Io {

From 3f5e718cb8d1553ea8c4ae9353e30dbbe09cd702 Mon Sep 17 00:00:00 2001
From: Philipp Oppermann <dev@phil-opp.com>
Date: Fri, 17 Jul 2020 08:58:54 +0200
Subject: [PATCH 02/10] Simplify config parsing by creating
 `parse_string_array` function

---
 src/config.rs | 38 ++++++++++++++------------------------
 1 file changed, 14 insertions(+), 24 deletions(-)

diff --git a/src/config.rs b/src/config.rs
index 44479d6..a8a597c 100644
--- a/src/config.rs
+++ b/src/config.rs
@@ -76,34 +76,13 @@ fn read_config_inner(manifest_path: &Path) -> Result<Config> {
                 config.test_success_exit_code = Some(exit_code as i32);
             }
             ("run-command", Value::Array(array)) => {
-                let mut command = Vec::new();
-                for value in array {
-                    match value {
-                        Value::String(s) => command.push(s),
-                        _ => return Err(anyhow!("run-command must be a list of strings")),
-                    }
-                }
-                config.run_command = Some(command);
+                config.run_command = Some(parse_string_array(array, "run-command")?);
             }
             ("run-args", Value::Array(array)) => {
-                let mut args = Vec::new();
-                for value in array {
-                    match value {
-                        Value::String(s) => args.push(s),
-                        _ => return Err(anyhow!("run-args must be a list of strings")),
-                    }
-                }
-                config.run_args = Some(args);
+                config.run_args = Some(parse_string_array(array, "run-args")?);
             }
             ("test-args", Value::Array(array)) => {
-                let mut args = Vec::new();
-                for value in array {
-                    match value {
-                        Value::String(s) => args.push(s),
-                        _ => return Err(anyhow!("test-args must be a list of strings")),
-                    }
-                }
-                config.test_args = Some(args);
+                config.test_args = Some(parse_string_array(array, "test-args")?);
             }
             (key, value) => {
                 return Err(anyhow!(
@@ -118,6 +97,17 @@ fn read_config_inner(manifest_path: &Path) -> Result<Config> {
     Ok(config.into())
 }
 
+fn parse_string_array(array: Vec<Value>, prop_name: &str) -> Result<Vec<String>> {
+    let mut parsed = Vec::new();
+    for value in array {
+        match value {
+            Value::String(s) => parsed.push(s),
+            _ => return Err(anyhow!("{} must be a list of strings", prop_name)),
+        }
+    }
+    Ok(parsed)
+}
+
 #[derive(Default)]
 struct ConfigBuilder {
     run_command: Option<Vec<String>>,

From 2e680f92686980762e417b7e3a204c369eeef264 Mon Sep 17 00:00:00 2001
From: Philipp Oppermann <dev@phil-opp.com>
Date: Fri, 17 Jul 2020 08:59:21 +0200
Subject: [PATCH 03/10] Add a build-command config option, defaulting to `cargo
 build`

---
 src/config.rs | 11 +++++++++++
 1 file changed, 11 insertions(+)

diff --git a/src/config.rs b/src/config.rs
index a8a597c..72105cc 100644
--- a/src/config.rs
+++ b/src/config.rs
@@ -12,6 +12,10 @@ use toml::Value;
 #[derive(Debug, Clone)]
 #[non_exhaustive]
 pub struct Config {
+    /// The command that is used for building the kernel for `cargo bootimage`.
+    ///
+    /// Defaults to `cargo build`.
+    pub build_command: Vec<String>,
     /// The run command that is invoked on `bootimage run` or `bootimage runner`
     ///
     /// The substring "{}" will be replaced with the path to the bootable disk image.
@@ -75,6 +79,9 @@ fn read_config_inner(manifest_path: &Path) -> Result<Config> {
             ("test-success-exit-code", Value::Integer(exit_code)) => {
                 config.test_success_exit_code = Some(exit_code as i32);
             }
+            ("build-command", Value::Array(array)) => {
+                config.build_command = Some(parse_string_array(array, "build-command")?);
+            }
             ("run-command", Value::Array(array)) => {
                 config.run_command = Some(parse_string_array(array, "run-command")?);
             }
@@ -110,6 +117,7 @@ fn parse_string_array(array: Vec<Value>, prop_name: &str) -> Result<Vec<String>>
 
 #[derive(Default)]
 struct ConfigBuilder {
+    build_command: Option<Vec<String>>,
     run_command: Option<Vec<String>>,
     run_args: Option<Vec<String>>,
     test_args: Option<Vec<String>>,
@@ -120,6 +128,9 @@ struct ConfigBuilder {
 impl Into<Config> for ConfigBuilder {
     fn into(self) -> Config {
         Config {
+            build_command: self
+                .build_command
+                .unwrap_or(vec!["cargo".into(), "build".into()]),
             run_command: self.run_command.unwrap_or_else(|| {
                 vec![
                     "qemu-system-x86_64".into(),

From 11501a40a43461a12da41afc401676ce5dc08578 Mon Sep 17 00:00:00 2001
From: Philipp Oppermann <dev@phil-opp.com>
Date: Fri, 17 Jul 2020 09:05:07 +0200
Subject: [PATCH 04/10] Use config.build_command instead of rlibc heuristic

This is a breaking change since it changes the default build command to `cargo build`.
---
 src/bin/cargo-bootimage.rs |  5 +++--
 src/builder/mod.rs         | 19 +++++--------------
 src/config.rs              |  8 +++-----
 3 files changed, 11 insertions(+), 21 deletions(-)

diff --git a/src/bin/cargo-bootimage.rs b/src/bin/cargo-bootimage.rs
index 1737866..3ea1690 100644
--- a/src/bin/cargo-bootimage.rs
+++ b/src/bin/cargo-bootimage.rs
@@ -2,7 +2,7 @@ use anyhow::{anyhow, Context, Result};
 use bootimage::{
     args::{BuildArgs, BuildCommand},
     builder::Builder,
-    help,
+    config, help,
 };
 use std::{
     env,
@@ -43,9 +43,10 @@ pub fn main() -> Result<()> {
 
 fn build(args: BuildArgs) -> Result<()> {
     let mut builder = Builder::new(args.manifest_path().map(PathBuf::from))?;
+    let config = config::read_config(builder.manifest_path())?;
     let quiet = args.quiet();
 
-    let executables = builder.build_kernel(&args.cargo_args(), quiet)?;
+    let executables = builder.build_kernel(&args.cargo_args(), &config, quiet)?;
     if executables.is_empty() {
         return Err(anyhow!("no executables built"));
     }
diff --git a/src/builder/mod.rs b/src/builder/mod.rs
index 3687c12..1474bfd 100644
--- a/src/builder/mod.rs
+++ b/src/builder/mod.rs
@@ -1,5 +1,6 @@
 //! Provides functions to build the kernel and the bootloader.
 
+use crate::config::Config;
 use cargo_metadata::Metadata;
 use error::{BootloaderError, BuildKernelError, BuilderError, CreateBootimageError};
 use std::{
@@ -46,27 +47,17 @@ impl Builder {
     pub fn build_kernel(
         &mut self,
         args: &[String],
+        config: &Config,
         quiet: bool,
     ) -> Result<Vec<PathBuf>, BuildKernelError> {
         if !quiet {
             println!("Building kernel");
         }
 
-        let build_arg = if self
-            .project_metadata()
-            .ok()
-            .and_then(|m| m.packages.iter().find(|p| p.name == "rlibc"))
-            .is_some()
-        {
-            "build"
-        } else {
-            "xbuild"
-        };
-
         // try to run cargo xbuild
         let cargo = std::env::var("CARGO").unwrap_or_else(|_| "cargo".to_owned());
         let mut cmd = process::Command::new(&cargo);
-        cmd.arg(build_arg);
+        cmd.args(&config.build_command);
         cmd.args(args);
         if !quiet {
             cmd.stdout(process::Stdio::inherit());
@@ -77,7 +68,7 @@ impl Builder {
             error: err,
         })?;
         if !output.status.success() {
-            if build_arg == "xbuild" {
+            if config.build_command.starts_with(&["xbuild".into()]) {
                 // try executing `cargo xbuild --help` to check whether cargo-xbuild is installed
                 let mut help_command = process::Command::new("cargo");
                 help_command.arg("xbuild").arg("--help");
@@ -96,7 +87,7 @@ impl Builder {
 
         // Retrieve binary paths
         let mut cmd = process::Command::new(cargo);
-        cmd.arg(build_arg);
+        cmd.args(&config.build_command);
         cmd.args(args);
         cmd.arg("--message-format").arg("json");
         let output = cmd.output().map_err(|err| BuildKernelError::Io {
diff --git a/src/config.rs b/src/config.rs
index 72105cc..bbed314 100644
--- a/src/config.rs
+++ b/src/config.rs
@@ -12,9 +12,9 @@ use toml::Value;
 #[derive(Debug, Clone)]
 #[non_exhaustive]
 pub struct Config {
-    /// The command that is used for building the kernel for `cargo bootimage`.
+    /// The cargo subcommand that is used for building the kernel for `cargo bootimage`.
     ///
-    /// Defaults to `cargo build`.
+    /// Defaults to `build`.
     pub build_command: Vec<String>,
     /// The run command that is invoked on `bootimage run` or `bootimage runner`
     ///
@@ -128,9 +128,7 @@ struct ConfigBuilder {
 impl Into<Config> for ConfigBuilder {
     fn into(self) -> Config {
         Config {
-            build_command: self
-                .build_command
-                .unwrap_or(vec!["cargo".into(), "build".into()]),
+            build_command: self.build_command.unwrap_or(vec!["build".into()]),
             run_command: self.run_command.unwrap_or_else(|| {
                 vec![
                     "qemu-system-x86_64".into(),

From 058439bf825afd9da56d898b85795458c7ab38a7 Mon Sep 17 00:00:00 2001
From: Philipp Oppermann <dev@phil-opp.com>
Date: Fri, 17 Jul 2020 10:06:06 +0200
Subject: [PATCH 05/10] Update example kernels to use `-Zbuild-std` and
 bootloader 0.9.7

---
 example-kernels/.cargo/config.toml        |  2 ++
 example-kernels/Cargo.lock                | 21 +++++++++++++++------
 example-kernels/basic/Cargo.toml          |  2 +-
 example-kernels/runner-doctest/Cargo.toml |  2 +-
 example-kernels/runner-test/Cargo.toml    |  2 +-
 example-kernels/runner/Cargo.toml         |  2 +-
 6 files changed, 21 insertions(+), 10 deletions(-)
 create mode 100644 example-kernels/.cargo/config.toml

diff --git a/example-kernels/.cargo/config.toml b/example-kernels/.cargo/config.toml
new file mode 100644
index 0000000..92cee48
--- /dev/null
+++ b/example-kernels/.cargo/config.toml
@@ -0,0 +1,2 @@
+[unstable]
+build-std = ["core", "compiler_builtins"]
diff --git a/example-kernels/Cargo.lock b/example-kernels/Cargo.lock
index 27d7cb0..514e054 100644
--- a/example-kernels/Cargo.lock
+++ b/example-kernels/Cargo.lock
@@ -4,7 +4,7 @@
 name = "basic"
 version = "0.1.0"
 dependencies = [
- "bootloader 0.9.3 (registry+https://github.com/rust-lang/crates.io-index)",
+ "bootloader 0.9.7 (registry+https://github.com/rust-lang/crates.io-index)",
  "x86_64 0.11.0 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
@@ -20,14 +20,22 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 
 [[package]]
 name = "bootloader"
-version = "0.9.3"
+version = "0.9.7"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "rlibc 1.0.0 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
+[[package]]
+name = "rlibc"
+version = "1.0.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 
 [[package]]
 name = "runner"
 version = "0.1.0"
 dependencies = [
- "bootloader 0.9.3 (registry+https://github.com/rust-lang/crates.io-index)",
+ "bootloader 0.9.7 (registry+https://github.com/rust-lang/crates.io-index)",
  "x86_64 0.11.0 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
@@ -35,7 +43,7 @@ dependencies = [
 name = "runner-doctest"
 version = "0.1.0"
 dependencies = [
- "bootloader 0.9.3 (registry+https://github.com/rust-lang/crates.io-index)",
+ "bootloader 0.9.7 (registry+https://github.com/rust-lang/crates.io-index)",
  "x86_64 0.11.0 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
@@ -43,7 +51,7 @@ dependencies = [
 name = "runner-test"
 version = "0.1.0"
 dependencies = [
- "bootloader 0.9.3 (registry+https://github.com/rust-lang/crates.io-index)",
+ "bootloader 0.9.7 (registry+https://github.com/rust-lang/crates.io-index)",
  "x86_64 0.11.0 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
@@ -59,5 +67,6 @@ dependencies = [
 [metadata]
 "checksum bit_field 0.9.0 (registry+https://github.com/rust-lang/crates.io-index)" = "ed8765909f9009617974ab6b7d332625b320b33c326b1e9321382ef1999b5d56"
 "checksum bitflags 1.1.0 (registry+https://github.com/rust-lang/crates.io-index)" = "3d155346769a6855b86399e9bc3814ab343cd3d62c7e985113d46a0ec3c281fd"
-"checksum bootloader 0.9.3 (registry+https://github.com/rust-lang/crates.io-index)" = "44ac0bdf4930c3c4d7f0d04eb6f15d7dcb9d5972b1ff9cd2bee0128112260fc7"
+"checksum bootloader 0.9.7 (registry+https://github.com/rust-lang/crates.io-index)" = "1e54086033cef68ed4b1729aeb1383a4d2e7d9bacd70db747a0a0bc0a420c831"
+"checksum rlibc 1.0.0 (registry+https://github.com/rust-lang/crates.io-index)" = "fc874b127765f014d792f16763a81245ab80500e2ad921ed4ee9e82481ee08fe"
 "checksum x86_64 0.11.0 (registry+https://github.com/rust-lang/crates.io-index)" = "365de37eb7c6da582cbb510dd0f3f1235d24ff6309a8a96e8a9909cc9bfd608f"
diff --git a/example-kernels/basic/Cargo.toml b/example-kernels/basic/Cargo.toml
index 60e18ca..76ddf5d 100644
--- a/example-kernels/basic/Cargo.toml
+++ b/example-kernels/basic/Cargo.toml
@@ -5,5 +5,5 @@ authors = ["Philipp Oppermann <dev@phil-opp.com>"]
 edition = "2018"
 
 [dependencies]
-bootloader = "0.9.3"
+bootloader = "0.9.7"
 x86_64 = "0.11.0"
diff --git a/example-kernels/runner-doctest/Cargo.toml b/example-kernels/runner-doctest/Cargo.toml
index 2e6dad8..3a162ec 100644
--- a/example-kernels/runner-doctest/Cargo.toml
+++ b/example-kernels/runner-doctest/Cargo.toml
@@ -5,7 +5,7 @@ authors = ["Philipp Oppermann <dev@phil-opp.com>"]
 edition = "2018"
 
 [dependencies]
-bootloader = "0.9.3"
+bootloader = "0.9.7"
 x86_64 = "0.11.0"
 
 [package.metadata.bootimage]
diff --git a/example-kernels/runner-test/Cargo.toml b/example-kernels/runner-test/Cargo.toml
index db005f8..552ff6b 100644
--- a/example-kernels/runner-test/Cargo.toml
+++ b/example-kernels/runner-test/Cargo.toml
@@ -9,7 +9,7 @@ name = "no-harness"
 harness = false
 
 [dependencies]
-bootloader = "0.9.3"
+bootloader = "0.9.7"
 x86_64 = "0.11.0"
 
 [package.metadata.bootimage]
diff --git a/example-kernels/runner/Cargo.toml b/example-kernels/runner/Cargo.toml
index 603ebc8..f1ab3db 100644
--- a/example-kernels/runner/Cargo.toml
+++ b/example-kernels/runner/Cargo.toml
@@ -5,7 +5,7 @@ authors = ["Philipp Oppermann <dev@phil-opp.com>"]
 edition = "2018"
 
 [dependencies]
-bootloader = "0.9.3"
+bootloader = "0.9.7"
 x86_64 = "0.11.0"
 
 [package.metadata.bootimage]

From 7e5f34389f264e91111254b6eb931a70f140b0a0 Mon Sep 17 00:00:00 2001
From: Philipp Oppermann <dev@phil-opp.com>
Date: Fri, 17 Jul 2020 10:07:16 +0200
Subject: [PATCH 06/10] Update Readme and help messages for new build-command
 config key

---
 Readme.md                         |  6 +++++-
 src/help/cargo_bootimage_help.txt | 10 ++++++++++
 2 files changed, 15 insertions(+), 1 deletion(-)

diff --git a/Readme.md b/Readme.md
index 9757b45..be79a2e 100644
--- a/Readme.md
+++ b/Readme.md
@@ -31,7 +31,7 @@ Now you can build the kernel project and create a bootable disk image from it by
 cargo bootimage --target your_custom_target.json [other_args]
 ```
 
-The command will invoke [`cargo xbuild`](https://github.com/rust-osdev/cargo-xbuild), forwarding all passed options. Then it will build the specified bootloader together with the kernel to create a bootable disk image.
+The command will invoke `cargo build`, forwarding all passed options. Then it will build the specified bootloader together with the kernel to create a bootable disk image.
 
 ### Running
 
@@ -60,6 +60,10 @@ Configuration is done through a through a `[package.metadata.bootimage]` table i
 
 ```toml
 [package.metadata.bootimage]
+# The cargo subcommand that will be used for building the kernel.
+#
+# For building using the `cargo-xbuild` crate, set this to `xbuild`.
+build-command = ["build"]
 # The command invoked with the created bootimage (the "{}" will be replaced
 # with the path to the bootable disk image)
 # Applies to `bootimage run` and `bootimage runner`
diff --git a/src/help/cargo_bootimage_help.txt b/src/help/cargo_bootimage_help.txt
index f8cabbf..16647ef 100644
--- a/src/help/cargo_bootimage_help.txt
+++ b/src/help/cargo_bootimage_help.txt
@@ -11,3 +11,13 @@ BUILD_OPTS:
     is downloaded and built, and then combined with the kernel into a bootable
     disk image.
 
+CONFIGURATION:
+    The behavior of `cargo bootimage` can be configured through a
+    `[package.metadata.bootimage]` table in the `Cargo.toml`. The
+    following options are available to configure the build behavior:
+
+    [package.metadata.bootimage]
+    # The cargo subcommand that will be used for building the kernel.
+    #
+    # For building using the `cargo-xbuild` crate, set this to `xbuild`.
+    build-command = ["build"]

From f886c1f874f178500983c8bb47692f2ced4fa1a6 Mon Sep 17 00:00:00 2001
From: Philipp Oppermann <dev@phil-opp.com>
Date: Fri, 17 Jul 2020 10:08:21 +0200
Subject: [PATCH 07/10] Remove mentions of `xbuild` from error variants and
 code comments

---
 src/builder/error.rs | 22 +++++++++++-----------
 src/builder/mod.rs   | 16 ++++++++--------
 2 files changed, 19 insertions(+), 19 deletions(-)

diff --git a/src/builder/error.rs b/src/builder/error.rs
index 86e6e14..5c0cab1 100644
--- a/src/builder/error.rs
+++ b/src/builder/error.rs
@@ -29,19 +29,19 @@ pub enum BuildKernelError {
     )]
     XbuildNotFound,
 
-    /// Running `cargo xbuild` failed.
+    /// Running `cargo build` failed.
     #[error("Kernel build failed.\nStderr: {}", String::from_utf8_lossy(.stderr))]
-    XbuildFailed {
+    BuildFailed {
         /// The standard error output.
         stderr: Vec<u8>,
     },
 
-    /// The output of `cargo xbuild --message-format=json` was not valid UTF-8
+    /// The output of `cargo build --message-format=json` was not valid UTF-8
     #[error("Output of kernel build with --message-format=json is not valid UTF-8:\n{0}")]
-    XbuildJsonOutputInvalidUtf8(std::string::FromUtf8Error),
-    /// The output of `cargo xbuild --message-format=json` was not valid JSON
+    BuildJsonOutputInvalidUtf8(std::string::FromUtf8Error),
+    /// The output of `cargo build --message-format=json` was not valid JSON
     #[error("Output of kernel build with --message-format=json is not valid JSON:\n{0}")]
-    XbuildJsonOutputInvalidJson(json::Error),
+    BuildJsonOutputInvalidJson(json::Error),
 }
 
 /// Represents an error that occurred when creating a bootimage.
@@ -59,7 +59,7 @@ pub enum CreateBootimageError {
     /// Building the bootloader failed
     #[error("Bootloader build failed.\nStderr: {}", String::from_utf8_lossy(.stderr))]
     BootloaderBuildFailed {
-        /// The `cargo xbuild` output to standard error
+        /// The `cargo build` output to standard error
         stderr: Vec<u8>,
     },
 
@@ -76,12 +76,12 @@ pub enum CreateBootimageError {
         error: io::Error,
     },
 
-    /// The output of `cargo xbuild --message-format=json` was not valid UTF-8
+    /// The output of `cargo build --message-format=json` was not valid UTF-8
     #[error("Output of bootloader build with --message-format=json is not valid UTF-8:\n{0}")]
-    XbuildJsonOutputInvalidUtf8(std::string::FromUtf8Error),
-    /// The output of `cargo xbuild --message-format=json` was not valid JSON
+    BuildJsonOutputInvalidUtf8(std::string::FromUtf8Error),
+    /// The output of `cargo build --message-format=json` was not valid JSON
     #[error("Output of bootloader build with --message-format=json is not valid JSON:\n{0}")]
-    XbuildJsonOutputInvalidJson(json::Error),
+    BuildJsonOutputInvalidJson(json::Error),
 }
 
 /// There is something wrong with the bootloader dependency.
diff --git a/src/builder/mod.rs b/src/builder/mod.rs
index 1474bfd..46e9361 100644
--- a/src/builder/mod.rs
+++ b/src/builder/mod.rs
@@ -38,7 +38,7 @@ impl Builder {
         &self.manifest_path
     }
 
-    /// Builds the kernel by executing `cargo xbuild` with the given arguments.
+    /// Builds the kernel by executing `cargo build` with the given arguments.
     ///
     /// Returns a list of paths to all built executables. For crates with only a single binary,
     /// the returned list contains only a single element.
@@ -54,7 +54,7 @@ impl Builder {
             println!("Building kernel");
         }
 
-        // try to run cargo xbuild
+        // try to build kernel
         let cargo = std::env::var("CARGO").unwrap_or_else(|_| "cargo".to_owned());
         let mut cmd = process::Command::new(&cargo);
         cmd.args(&config.build_command);
@@ -80,7 +80,7 @@ impl Builder {
                     }
                 }
             }
-            return Err(BuildKernelError::XbuildFailed {
+            return Err(BuildKernelError::BuildFailed {
                 stderr: output.stderr,
             });
         }
@@ -95,17 +95,17 @@ impl Builder {
             error: err,
         })?;
         if !output.status.success() {
-            return Err(BuildKernelError::XbuildFailed {
+            return Err(BuildKernelError::BuildFailed {
                 stderr: output.stderr,
             });
         }
         let mut executables = Vec::new();
         for line in String::from_utf8(output.stdout)
-            .map_err(BuildKernelError::XbuildJsonOutputInvalidUtf8)?
+            .map_err(BuildKernelError::BuildJsonOutputInvalidUtf8)?
             .lines()
         {
             let mut artifact =
-                json::parse(line).map_err(BuildKernelError::XbuildJsonOutputInvalidJson)?;
+                json::parse(line).map_err(BuildKernelError::BuildJsonOutputInvalidJson)?;
             if let Some(executable) = artifact["executable"].take_string() {
                 executables.push(PathBuf::from(executable));
             }
@@ -165,11 +165,11 @@ impl Builder {
         }
         let mut bootloader_elf_path = None;
         for line in String::from_utf8(output.stdout)
-            .map_err(CreateBootimageError::XbuildJsonOutputInvalidUtf8)?
+            .map_err(CreateBootimageError::BuildJsonOutputInvalidUtf8)?
             .lines()
         {
             let mut artifact =
-                json::parse(line).map_err(CreateBootimageError::XbuildJsonOutputInvalidJson)?;
+                json::parse(line).map_err(CreateBootimageError::BuildJsonOutputInvalidJson)?;
             if let Some(executable) = artifact["executable"].take_string() {
                 if bootloader_elf_path
                     .replace(PathBuf::from(executable))

From 2cb9a9753890fbe5f407cfa3915311c7b0bb7779 Mon Sep 17 00:00:00 2001
From: Philipp Oppermann <dev@phil-opp.com>
Date: Fri, 17 Jul 2020 10:06:44 +0200
Subject: [PATCH 08/10] Don't install cargo-xbuild on CI

It should be no longer necessary.
---
 .github/workflows/build.yml | 14 ++++++--------
 1 file changed, 6 insertions(+), 8 deletions(-)

diff --git a/.github/workflows/build.yml b/.github/workflows/build.yml
index d2de177..1c42ab5 100644
--- a/.github/workflows/build.yml
+++ b/.github/workflows/build.yml
@@ -62,8 +62,6 @@ jobs:
 
     - name: "Install Rustup Components"
       run: rustup component add rust-src llvm-tools-preview
-    - name: "Install cargo-xbuild"
-      run: cargo install cargo-xbuild --debug
 
      # install QEMU
     - name: Install QEMU (Linux)
@@ -103,20 +101,20 @@ jobs:
       shell: bash {0}
       working-directory: example-kernels
 
-    - name: 'Run `cargo xrun` for "runner" kernel'
+    - name: 'Run `cargo run` for "runner" kernel'
       run: |
-        cargo xrun
+        cargo run
         if [ $? -eq 109 ]; then (exit 0); else (exit 1); fi
       shell: bash {0}
       working-directory: example-kernels/runner
 
-    - run: cargo xtest
+    - run: cargo test
       working-directory: example-kernels/runner-test
-      name: 'Run `cargo xtest` for "runner-test" kernel'
+      name: 'Run `cargo test` for "runner-test" kernel'
 
-    - run: cargo xtest -Z doctest-xcompile
+    - run: cargo test -Z doctest-xcompile
       working-directory: example-kernels/runner-doctest
-      name: 'Run `cargo xtest -Z doctest-xcompile` for "runner-doctest" kernel'
+      name: 'Run `cargo test -Z doctest-xcompile` for "runner-doctest" kernel'
 
   check_formatting:
     name: "Check Formatting"

From 8271e9e9b57cc2523b46ddbf18aba9100e40881c Mon Sep 17 00:00:00 2001
From: Philipp Oppermann <dev@phil-opp.com>
Date: Fri, 17 Jul 2020 10:18:40 +0200
Subject: [PATCH 09/10] Fix clippy warning (`unwrap_or` followed by function
 call)

---
 src/config.rs | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/config.rs b/src/config.rs
index bbed314..ed909e7 100644
--- a/src/config.rs
+++ b/src/config.rs
@@ -128,7 +128,7 @@ struct ConfigBuilder {
 impl Into<Config> for ConfigBuilder {
     fn into(self) -> Config {
         Config {
-            build_command: self.build_command.unwrap_or(vec!["build".into()]),
+            build_command: self.build_command.unwrap_or_else(|| vec!["build".into()]),
             run_command: self.run_command.unwrap_or_else(|| {
                 vec![
                     "qemu-system-x86_64".into(),

From b3aaf4f1810fe61e3cacd6eae435fdbc5e28dbaa Mon Sep 17 00:00:00 2001
From: Philipp Oppermann <dev@phil-opp.com>
Date: Fri, 17 Jul 2020 10:23:47 +0200
Subject: [PATCH 10/10] Add rlibc dependency where needed to example kernels

---
 example-kernels/runner-doctest/Cargo.toml | 1 +
 example-kernels/runner-doctest/src/lib.rs | 2 ++
 example-kernels/runner-test/Cargo.toml    | 1 +
 example-kernels/runner-test/src/lib.rs    | 2 ++
 4 files changed, 6 insertions(+)

diff --git a/example-kernels/runner-doctest/Cargo.toml b/example-kernels/runner-doctest/Cargo.toml
index 3a162ec..d1610e2 100644
--- a/example-kernels/runner-doctest/Cargo.toml
+++ b/example-kernels/runner-doctest/Cargo.toml
@@ -7,6 +7,7 @@ edition = "2018"
 [dependencies]
 bootloader = "0.9.7"
 x86_64 = "0.11.0"
+rlibc = "1.0.0"
 
 [package.metadata.bootimage]
 test-success-exit-code = 33 # (0x10 << 1) | 1
diff --git a/example-kernels/runner-doctest/src/lib.rs b/example-kernels/runner-doctest/src/lib.rs
index 3cdb90f..437f374 100644
--- a/example-kernels/runner-doctest/src/lib.rs
+++ b/example-kernels/runner-doctest/src/lib.rs
@@ -4,6 +4,8 @@
 #![test_runner(crate::test_runner)]
 #![reexport_test_harness_main = "test_main"]
 
+extern crate rlibc;
+
 /// add two numbers
 ///
 /// ```
diff --git a/example-kernels/runner-test/Cargo.toml b/example-kernels/runner-test/Cargo.toml
index 552ff6b..854ceb9 100644
--- a/example-kernels/runner-test/Cargo.toml
+++ b/example-kernels/runner-test/Cargo.toml
@@ -11,6 +11,7 @@ harness = false
 [dependencies]
 bootloader = "0.9.7"
 x86_64 = "0.11.0"
+rlibc = "1.0.0"
 
 [package.metadata.bootimage]
 test-success-exit-code = 33 # (0x10 << 1) | 1
diff --git a/example-kernels/runner-test/src/lib.rs b/example-kernels/runner-test/src/lib.rs
index 64c2518..740e7a9 100644
--- a/example-kernels/runner-test/src/lib.rs
+++ b/example-kernels/runner-test/src/lib.rs
@@ -5,6 +5,8 @@
 #![test_runner(crate::test_runner)]
 #![reexport_test_harness_main = "test_main"]
 
+extern crate rlibc;
+
 pub fn test_runner(tests: &[&dyn Fn()]) {
     for test in tests.iter() {
         test();