Init: Introduce support for conditionally spawning services

depending on the architecture and selected board. With this the
migration of initfs daemons to service definitions is almost done.

init/src/main.rs

@@ -50,6 +50,7 @@ impl InitConfig {
 }
 
 #[derive(Clone, Deserialize)]
+#[serde(deny_unknown_fields)]
 struct SwitchRoot {
     prefix: PathBuf,
     etcdir: PathBuf,
@@ -112,7 +113,7 @@ fn run(
         unit::UnitKind::Target {} => {
             if config.log_debug {
                 eprintln!(
-                    "Started target {}",
+                    "Reached target {}",
                     unit.info.description.as_ref().unwrap_or(&unit.id.0),
                 );
             }
@@ -171,6 +172,22 @@ fn main() {
     let runtime_target = UnitId("00_runtime.target".to_owned());
 
     'a: while let Some(unit) = pending_units.pop_front() {
+        if let Some(condition_architecture) = &unit_store.unit(&unit).info.condition_architecture {
+            if !condition_architecture
+                .iter()
+                .any(|arch| arch == std::env::consts::ARCH)
+            {
+                continue 'a;
+            }
+        }
+        if let Some(condition_board) = &unit_store.unit(&unit).info.condition_board {
+            if !condition_board
+                .iter()
+                .any(|board| Some(&**board) == option_env!("BOARD"))
+            {
+                continue 'a;
+            }
+        }
         if unit_store.unit(&unit).info.default_dependencies {
             if pending_units.contains(&runtime_target) {
                 pending_units.push_back(unit);

init/src/service.rs

@@ -6,6 +6,7 @@ use std::process::Command;
 use serde::Deserialize;
 
 #[derive(Clone, Debug, Deserialize)]
+#[serde(deny_unknown_fields)]
 pub struct Service {
     pub cmd: String,
     #[serde(default)]

init/src/unit.rs

@@ -77,12 +77,16 @@ pub struct Unit {
 }
 
 #[derive(Deserialize)]
+#[serde(deny_unknown_fields)]
 pub struct UnitInfo {
     pub description: Option<String>,
     #[serde(default = "true_bool")]
     pub default_dependencies: bool,
     #[serde(default)]
     pub requires_weak: Vec<UnitId>,
+    pub condition_architecture: Option<Vec<String>>,
+    // FIXME replace this with hwd reading from the devicetree
+    pub condition_board: Option<Vec<String>>,
 }
 
 fn true_bool() -> bool {
@@ -97,17 +101,20 @@ pub enum UnitKind {
 }
 
 #[derive(Deserialize)]
+#[serde(deny_unknown_fields)]
 struct SerializedService {
     unit: UnitInfo,
     service: Service,
 }
 
 #[derive(Deserialize)]
+#[serde(deny_unknown_fields)]
 struct SerializedTarget {
     unit: UnitInfo,
 }
 
 #[derive(Deserialize)]
+#[serde(deny_unknown_fields)]
 struct SerializedSwitchRoot {
     unit: UnitInfo,
     switchroot: SwitchRoot,
@@ -143,6 +150,8 @@ impl Unit {
                         description: None,
                         default_dependencies: true,
                         requires_weak,
+                        condition_architecture: None,
+                        condition_board: None,
                     },
                     UnitKind::LegacyScript { script },
                     warnings,