arch: implement dummy CpuFeatures for aarch64

kernel/arch/aarch64/src/lib.rs

@@ -49,6 +49,7 @@ impl ArchitectureImpl {
 
 impl Architecture for ArchitectureImpl {
     type PerCpuData = PerCpuData;
+    type CpuFeatures = ();
 
     fn cpu_index<S: Scheduler + 'static>() -> u32 {
         (MPIDR_EL1.get() & 0xFF) as u32
@@ -118,4 +119,12 @@ impl Architecture for ArchitectureImpl {
     fn message_interrupt_controller() -> &'static dyn MessageInterruptController {
         todo!()
     }
+
+    fn cpu_available_features<S: Scheduler>(_cpu: &CpuImpl<Self, S>) -> Option<&Self::CpuFeatures> {
+        None
+    }
+
+    fn cpu_enabled_features<S: Scheduler>(_cpu: &CpuImpl<Self, S>) -> Option<&Self::CpuFeatures> {
+        None
+    }
 }

kernel/arch/interface/src/cpu.rs

@@ -164,3 +164,9 @@ impl<A: Architecture> IpiQueue<A> {
         lock.take()
     }
 }
+
+impl CpuFeatureSet for () {
+    fn iter(&self) -> impl Iterator<Item = &'static str> {
+        core::iter::empty()
+    }
+}

kernel/arch/x86/src/lib.rs

@@ -1,4 +1,5 @@
 #![feature(iter_chain)]
+#![allow(clippy::new_without_default)]
 #![no_std]
 
 pub mod cpuid;