kernel: add debug command to print interrupts

This can be used to ensure the interrupt handlers are where we think
they are.

Signed-off-by: Sean Cross <sean@xobs.io>

kernel/src/debug/mod.rs

@@ -167,6 +167,21 @@ fn process_irq_character(b: u8) {
     }
 
     match b {
+        b'i' => {
+            println!("Interrupt handlers:");
+            println!("  IRQ | Process | Handler | Argument");
+            crate::services::SystemServices::with(|system_services| {
+                crate::irq::for_each_irq(|irq, pid, address, arg| {
+                    println!(
+                        "    {}:  {} @ {:x?} {:x?}",
+                        irq,
+                        system_services.process_name(*pid).unwrap_or(""),
+                        address,
+                        arg
+                    );
+                });
+            });
+        }
         b'm' => {
             println!("Printing memory page tables");
             crate::services::SystemServices::with(|system_services| {
@@ -268,6 +283,7 @@ fn process_irq_character(b: u8) {
             println!("--- + -----------------------");
             #[cfg(all(feature = "gdbserver", baremetal))]
             println!(" g  | enter the gdb server");
+            println!(" i  | print irq handlers");
             println!(" m  | print MMU page tables of all processes");
             println!(" p  | print all processes");
             println!(" P  | print all processes and threads");

kernel/src/irq.rs

@@ -44,6 +44,20 @@ pub fn handle(irqs_pending: usize) -> Result<xous_kernel::Result, xous_kernel::E
     Ok(xous_kernel::Result::ResumeProcess)
 }
 
+pub fn for_each_irq<F>(op: F)
+where
+    F: Fn(usize, &PID, MemoryAddress, Option<MemoryAddress>),
+{
+    unsafe {
+        for (idx, handler) in IRQ_HANDLERS.iter().enumerate() {
+            // Ignore threads that have no PC, and ignore the ISR thread
+            if let Some(handler) = handler {
+                op(idx, &handler.0, handler.1, handler.2);
+            }
+        }
+    }
+}
+
 pub fn interrupt_claim(
     irq: usize,
     pid: PID,