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.d.aarch64-unknown-redox/40_drivers

@@ -1,3 +0,0 @@
-requires_weak 10_lived.service 20_graphics.target
-notify RSDP_ADDR=$ RSDP_SIZE=$ hwd
-pcid-spawner --initfs

init.d.aarch64-unknown-redox/40_drivers.raspi3bp

@@ -1,2 +0,0 @@
-requires_weak 10_lived.service 20_graphics.target
-notify bcm2835-sdhcid

init.d/40_bcm2835-sdhcid.service

@@ -0,0 +1,9 @@
+[unit]
+description = "BCM2835 SD card driver"
+requires_weak = ["10_inputd.service", "10_lived.service", "20_graphics.target"]
+condition_architecture = ["aarch64"]
+condition_board = ["raspi3bp"]
+
+[service]
+cmd = "bcm2835-sdhcid"
+type = "notify"

init.d/40_drivers

@@ -1,4 +0,0 @@
-requires_weak 10_lived.service 20_graphics.target
-notify ps2d
-notify RSDP_ADDR=$ RSDP_SIZE=$ hwd
-pcid-spawner --initfs

init.d/40_drivers.target

@@ -0,0 +1,10 @@
+[unit]
+description = "Initfs drivers"
+requires_weak = [
+    "10_lived.service",
+    "20_graphics.target",
+    "40_ps2d.service",
+    "40_bcm2835-sdhcid.service",
+    "40_hwd.service",
+    "40_pcid-spawner.service",
+]

init.d/40_hwd.service

@@ -0,0 +1,11 @@
+[unit]
+description = "Hardware manager"
+requires_weak = ["10_inputd.service", "10_lived.service", "20_graphics.target"]
+
+[service]
+cmd = "hwd"
+inherit_envs = [
+    "RSDP_ADDR",
+    "RSDP_SIZE",
+]
+type = "notify"

init.d/40_pcid-spawner.service

@@ -0,0 +1,8 @@
+[unit]
+description = "PCI driver spawner"
+requires_weak = ["10_inputd.service", "20_graphics.target", "40_hwd.service"]
+
+[service]
+cmd = "pcid-spawner"
+args = ["--initfs"]
+type = "oneshot"

init.d/40_ps2d.service

@@ -0,0 +1,8 @@
+[unit]
+description = "PS/2 driver"
+requires_weak = ["10_inputd.service", "20_graphics.target"]
+condition_architecture = ["x86", "x86_64"]
+
+[service]
+cmd = "ps2d"
+type = "notify"

init.d/50_rootfs

@@ -1,2 +1,2 @@
-requires_weak 40_drivers
+requires_weak 40_drivers.target
 REDOXFS_PASSWORD_ADDR=$ REDOXFS_PASSWORD_SIZE=$ redoxfs --uuid $REDOXFS_UUID file $REDOXFS_BLOCK

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,