xtask: add cargo xtask command

This command can be used to build a full image.

Signed-off-by: Sean Cross <sean@xobs.io>

.cargo/config

@@ -0,0 +1,2 @@
+[alias]
+xtask = "run --package xtask --"

xtask/Cargo.toml

@@ -0,0 +1,9 @@
+[package]
+name = "xtask"
+version = "0.1.0"
+authors = ["Sean Cross <sean@xobs.io>"]
+edition = "2018"
+
+# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
+
+[dependencies]

xtask/src/main.rs

@@ -0,0 +1,137 @@
+use std::{
+    env, fs,
+    path::{Path, PathBuf},
+    process::Command,
+};
+
+type DynError = Box<dyn std::error::Error>;
+
+const TARGET: &str = "riscv32imac-unknown-none-elf";
+
+#[derive(Debug)]
+enum BuildError {
+    PathConversionError,
+}
+
+impl std::fmt::Display for BuildError {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        match *self {
+            BuildError::PathConversionError => write!(f, "could not convert path to UTF-8"),
+        }
+    }
+}
+
+impl std::error::Error for BuildError {}
+
+fn main() {
+    if let Err(e) = try_main() {
+        eprintln!("{}", e);
+        std::process::exit(-1);
+    }
+}
+
+fn try_main() -> Result<(), DynError> {
+    let task = env::args().nth(1);
+    match task.as_deref() {
+        Some("image") => image()?,
+        _ => print_help(),
+    }
+    Ok(())
+}
+
+fn print_help() {
+    eprintln!(
+        "Tasks:
+renode-image            builds a test image for renode
+"
+    )
+}
+
+fn image() -> Result<(), DynError> {
+    let debug = false;
+    let _ = fs::remove_dir_all(&dist_dir());
+    fs::create_dir_all(&dist_dir())?;
+
+    let kernel = build_kernel(debug)?;
+    let mut init = vec![];
+    for pkg in &["shell", "log-server", "graphics-server"] {
+        init.push(build(pkg, debug, None)?);
+    }
+
+    create_image(&kernel, &init, debug)?;
+
+    Ok(())
+}
+
+fn build_kernel(debug: bool) -> Result<PathBuf, DynError> {
+    build("kernel", debug, Some("kernel".into()))
+}
+
+fn build(project: &str, debug: bool, directory: Option<PathBuf>) -> Result<PathBuf, DynError> {
+    let stream = if debug { "debug" } else { "release" };
+    let mut args = vec!["build", "--target", TARGET, "--package", project];
+    if !debug {
+        args.push("--release");
+    }
+
+    let mut dir = project_root();
+    if let Some(subdir) = directory {
+        dir.push(subdir);
+    }
+
+    let status = Command::new(cargo())
+        .current_dir(dir)
+        .args(&args)
+        .status()?;
+
+    if !status.success() {
+        return Err("cargo build failed".into());
+    }
+
+    Ok(project_root().join(&format!("target/{}/{}/{}", TARGET, stream, project)))
+}
+
+fn create_image(kernel: &Path, init: &[PathBuf], debug: bool) -> Result<PathBuf, DynError> {
+    let stream = if debug { "debug" } else { "release" };
+    let mut args = vec!["run", "--package", "tools", "--bin", "create-image", "--"];
+
+    let output_file = format!("target/{}/{}/args.bin", TARGET, stream);
+    args.push(&output_file);
+
+    args.push("--kernel");
+    args.push(kernel.to_str().ok_or(BuildError::PathConversionError)?);
+
+    for i in init {
+        args.push("--init");
+        args.push(i.to_str().ok_or(BuildError::PathConversionError)?);
+    }
+
+    args.push("--csv");
+    args.push("emulation/csr.csv");
+
+    let status = Command::new(cargo())
+        .current_dir(project_root())
+        .args(&args)
+        .status()?;
+
+    if !status.success() {
+        return Err("cargo build failed".into());
+    }
+    Ok(project_root().join(&format!("target/{}/{}/args.bin", TARGET, stream)))
+}
+
+fn cargo() -> String {
+    env::var("CARGO").unwrap_or_else(|_| "cargo".to_string())
+}
+
+fn project_root() -> PathBuf {
+    Path::new(&env!("CARGO_MANIFEST_DIR"))
+        .ancestors()
+        .nth(1)
+        .unwrap()
+        .to_path_buf()
+}
+
+fn dist_dir() -> PathBuf {
+    project_root().join("target/dist")
+}