feat(kernel): dump commands for GDT and timer (#375)

src/arch/x86_64.rs

@@ -14,6 +14,7 @@ mod framebuf;
 pub mod interrupt;
 mod oops;
 pub mod pci;
+pub mod shell;
 pub use self::{
     boot::ArchInfo,
     oops::{oops, Oops},

src/arch/x86_64/interrupt.rs

@@ -54,7 +54,7 @@ static TSS: sync::Lazy<task::StateSegment> = sync::Lazy::new(|| {
     tss
 });
 
-static GDT: sync::InitOnce<Gdt> = sync::InitOnce::uninitialized();
+pub(in crate::arch) static GDT: sync::InitOnce<Gdt> = sync::InitOnce::uninitialized();
 
 const TIMER_INTERVAL: time::Duration = time::Duration::from_millis(10);
 pub(super) static TIMER: time::Timer = time::Timer::new(TIMER_INTERVAL);

src/arch/x86_64/shell.rs

@@ -0,0 +1,25 @@
+use crate::shell::{self, Command};
+
+pub const DUMP_ARCH: Command = Command::new("arch")
+    .with_help("dump architecture-specific structures")
+    .with_subcommands(&[
+        Command::new("gdt")
+            .with_help("print the global descriptor table (GDT)")
+            .with_fn(|_| {
+                let gdt = super::interrupt::GDT.get();
+                tracing::info!(?gdt);
+                Ok(())
+            }),
+        // Command::new("idt")
+        //     .with_help("print the interrupt descriptor table (IDT)")
+        //     .with_fn(|_| {
+        //         let gdt = super::interrupt::GDT.get();
+        //         tracing::info!(?gdt);
+        //         Ok(())
+        //     }),
+    ]);
+
+pub fn dump_timer(_: &str) -> Result<(), shell::Error> {
+    tracing::info!(timer = ?super::interrupt::TIMER);
+    Ok(())
+}

src/shell.rs

@@ -40,6 +40,13 @@ pub fn eval(line: &str) {
             Command::new("archinfo")
                 .with_help("print the architecture information structure")
                 .with_fn(|line| Err(Error::other(line, "not yet implemented"))),
+            Command::new("timer")
+                .with_help("print the timer wheel")
+                .with_fn(crate::arch::shell::dump_timer),
+            Command::new("timer")
+                .with_help("print the timer wheel")
+                .with_fn(crate::arch::shell::dump_timer),
+            crate::arch::shell::DUMP_ARCH,
             Command::new("heap")
                 .with_help("print kernel heap statistics")
                 .with_fn(|_| {