feat: template for scheduler

.vscode/settings.json

@@ -11,4 +11,5 @@
     "rust-analyzer.linkedProjects": [
         "./kernel/Cargo.toml"
     ],
+    "rust-analyzer.showUnlinkedFileNotification": false,
 }

kernel/src/arch/riscv/trap.rs

@@ -1,11 +1,11 @@
 use crate::entry::HART_ID;
 use crate::plat::console::CONSOLE;
-use log::trace;
-use riscv::register::scause::{Interrupt as I, Trap as T};
-use riscv::register::stvec::TrapMode;
-
 use crate::plat::timer::{Timer, TimerOps};
 use crate::plat::trap::{Trap, TrapContextOps, TrapOps};
+use crate::scheduler::SCHEDULER;
+use log::trace;
+use riscv::register::scause::{Exception as E, Interrupt as I, Trap as T};
+use riscv::register::stvec::TrapMode;
 
 core::arch::global_asm!(include_str!("./asm/trap64.S"));
 core::arch::global_asm!(include_str!("./asm/trap_common.S"));
@@ -17,29 +17,52 @@ extern "C" {
 
 #[no_mangle]
 extern "C" fn kernel_trap_handler(tf: &mut TrapContext) {
-    // TODO: consider redesigning this, should we allow trap in kernel?
+    // TODO: Replace CONSOLE Mutex to ReentrantLock
     unsafe { CONSOLE.force_unlock() }
     trap_handler(tf, true)
 }
 
-fn trap_handler(_tf: &mut TrapContext, _from_kernel: bool) {
+fn trap_handler(tf: &mut TrapContext, from_kernel: bool) {
     let scause = riscv::register::scause::read();
-    trace!("[Interrupt] cpu@{} scause: {:?}", HART_ID.get(), scause.cause());
+    trace!("[Trap] cpu@{} scause: {:?}", HART_ID.get(), scause.cause());
+
+    macro_rules! panic_fatal {
+        ($msg:expr) => {
+            panic!(
+                "[Trap] {}, scause: {:?}, bits: {:#x}, sepc: {:#x}, stval: {:#x}",
+                $msg,
+                scause.cause(),
+                scause.bits(),
+                tf.sepc,
+                riscv::register::stval::read()
+            )
+        };
+    }
+
     match scause.cause() {
         T::Interrupt(I::SupervisorTimer) => {
-            // TODO: refactor this
+            if !from_kernel {
-            trace!("[Interrupt] Tick: {}", riscv::register::time::read64());
+                SCHEDULER.schedule()
-            Timer::tick();
+            }
         },
-        _ => {
+        T::Exception(E::UserEnvCall) => {
-            panic!(
+            // TODO: handle syscall
-                "[Interrupt] Unhandled Trap, scause: {:?}, bits: {:#x}",
+            tf.sepc += 4;
-                scause.cause(),
-                scause.bits()
-            );
         },
+        T::Interrupt(I::SupervisorExternal) => {
+            // TODO: handle external interrupt, e.g. plic
+        },
+        T::Exception(E::InstructionPageFault) | T::Exception(E::LoadPageFault) | T::Exception(E::StorePageFault) => {
+            if from_kernel {
+                panic_fatal!("Page Fault in Kernel");
+            }
+            // TODO: handle page fault
+        },
+        _ => panic_fatal!("Unhandled Trap"),
     }
-    trace!("[Interrupt] exiting...");
+
+    Timer::tick();
+    trace!("[Trap] exiting...");
 }
 
 impl TrapOps for Trap {

kernel/src/main.rs

@@ -29,6 +29,7 @@ mod lang;
 mod logging;
 mod objects;
 mod plat;
+mod scheduler;
 
 // test infrastructure
 #[cfg(test)]

kernel/src/scheduler/mod.rs

@@ -0,0 +1,15 @@
+pub static SCHEDULER: Scheduler = Scheduler::new();
+
+pub struct Scheduler {}
+
+impl Scheduler {
+    pub const fn new() -> Self {
+        // TODO: implement Scheduler::new
+        Self {}
+    }
+
+    #[inline(never)]
+    pub fn schedule(&self) {
+        todo!("Scheduler::schedule");
+    }
+}