feat(config): support for setting the default entry to boot

src/config.rs

@@ -22,6 +22,9 @@ pub struct RootConfiguration {
     /// the configuration is the latest version.
     #[serde(default = "latest_version")]
     pub version: u32,
+    /// Default options for Sprout.
+    #[serde(default)]
+    pub defaults: DefaultsConfiguration,
     /// Values to be inserted into the root sprout context.
     #[serde(default)]
     pub values: BTreeMap<String, String>,
@@ -59,6 +62,14 @@ pub struct RootConfiguration {
     pub phases: PhasesConfiguration,
 }
 
+/// Default configuration for Sprout, used when the corresponding options are not specified.
+#[derive(Serialize, Deserialize, Default, Clone)]
+pub struct DefaultsConfiguration {
+    /// The entry to boot without showing the boot menu.
+    /// If not specified, a boot menu is shown.
+    pub entry: Option<String>,
+}
+
 fn latest_version() -> u32 {
     LATEST_VERSION
 }

src/main.rs

@@ -164,13 +164,23 @@ fn main() -> Result<()> {
     // Execute the late phase.
     phase(context.clone(), &config.phases.late).context("unable to execute late phase")?;
 
+    // If --boot is specified, or defaults.entry is specified, use that to find the entry to boot.
+    let boot = context
+        .root()
+        .options()
+        .boot
+        .as_ref()
+        .or(config.defaults.entry.as_ref());
+
     // Use the boot option if possible, otherwise pick the first entry.
-    let entry = if let Some(ref boot) = context.root().options().boot {
+    let entry = if let Some(ref boot) = boot {
         entries
             .iter()
             .enumerate()
             .find(|(index, entry)| {
-                entry.name() == boot || entry.title() == boot || &index.to_string() == boot
+                entry.name() == boot.as_str()
+                    || entry.title() == boot.as_str()
+                    || index.to_string() == boot.as_str()
             })
             .context(format!("unable to find entry: {boot}"))?
             .1 // select the bootable entry.