Use null driver for unknown IRQ controllers on aarch64

src/arch/aarch64/device/irqchip/mod.rs

@@ -6,6 +6,7 @@ mod gic;
 mod gicv3;
 mod irq_bcm2835;
 mod irq_bcm2836;
+mod null;
 
 pub(crate) fn new_irqchip(ic_str: &str) -> Option<Box<dyn InterruptController>> {
     if ic_str.contains("arm,gic-v3") {
@@ -18,7 +19,8 @@ pub(crate) fn new_irqchip(ic_str: &str) -> Option<Box<dyn InterruptController>>
         Some(Box::new(irq_bcm2835::Bcm2835ArmInterruptController::new()))
     } else {
         log::warn!("no driver for interrupt controller {:?}", ic_str);
-        None
+        //TODO: return None and handle it properly
+        Some(Box::new(null::Null))
     }
 }
 

src/arch/aarch64/device/irqchip/null.rs

@@ -0,0 +1,41 @@
+use fdt::Fdt;
+use syscall::{
+    error::{Error, EINVAL},
+    Result,
+};
+
+use super::InterruptController;
+use crate::dtb::irqchip::{InterruptHandler, IrqDesc};
+
+pub struct Null;
+
+impl InterruptHandler for Null {
+    fn irq_handler(&mut self, _irq: u32) {}
+}
+
+impl InterruptController for Null {
+    fn irq_init(
+        &mut self,
+        fdt: &Fdt,
+        irq_desc: &mut [IrqDesc; 1024],
+        ic_idx: usize,
+        irq_idx: &mut usize,
+    ) -> Result<()> {
+        Ok(())
+    }
+    fn irq_ack(&mut self) -> u32 {
+        unimplemented!()
+    }
+    fn irq_eoi(&mut self, irq_num: u32) {
+    }
+    fn irq_enable(&mut self, irq_num: u32) {
+    }
+    fn irq_disable(&mut self, irq_num: u32) {
+    }
+    fn irq_xlate(&self, irq_data: &[u32; 3]) -> Result<usize> {
+        Err(Error::new(EINVAL))
+    }
+    fn irq_to_virq(&self, hwirq: u32) -> Option<usize> {
+        None
+    }
+}