添加时钟中断处理

ch3/os/src/main.rs

@@ -8,13 +8,18 @@ use lang_items::console;
 
 pub mod lang_items;
 pub mod sbi;
-// pub mod batch;
 pub mod sync;
 pub mod trap;
 pub mod syscall;
 pub mod loader;
 pub mod config;
 pub mod task;
+pub mod timer;
+
+#[path = "boards/qemu.rs"]
+mod board;
+
+
 
 // 汇编脚本引入, 调整内核的内存布局之后, 会跳入到 rust_main中执行
 global_asm!(include_str!("entry.asm"));
@@ -40,13 +45,13 @@ pub fn rust_main(){
     println!("boot_stack_top_bound: {:#x}, boot_stack_lower_bound: {:#x}", boot_stack_top_bound as usize, boot_stack_lower_bound as usize);
 
     trap::init();
+
     loader::load_app();
+    trap::enable_timer_interrupt();  // 允许定时器中断
+    timer::set_next_trigger();  // 在进入用户态之前, 设置一个时钟中断, 防止第一个用户任务死循环
     task::run_first_task();
-    // batch::init();
-    // batch::run_next_app();
-    loop {
 
-    }
+    panic!("Disable run here")
 }
 
 /// ## 初始化bss段

ch3/os/src/sbi.rs

@@ -38,3 +38,8 @@ pub fn shutdown() -> ! {
     sbi_call(SRST_EXTENSION, SBI_SHUTDOWN, 0, 0, 0);
     panic!("It should shutdown!")
 }
+
+// 设置 mtimecmp 的值
+pub fn set_timer(timer: usize) {
+    sbi_call(SBI_SET_TIMER, timer, 0, 0, 0);
+}

ch3/os/src/syscall/mod.rs

@@ -1,6 +1,7 @@
 const SYSCALL_WRITE: usize = 64;
 const SYSCALL_EXIT: usize = 93;
 const SYSCALL_YIELD: usize = 124;
+const SYSCALL_GET_TIME: usize = 169;
 
 mod fs;
 mod process;
@@ -14,6 +15,7 @@ pub fn syscall(syscall_id: usize, args: [usize; 3]) -> isize {
         SYSCALL_WRITE => sys_write(args[0], args[1] as *const u8, args[2]),
         SYSCALL_EXIT => sys_exit(args[0] as i32),
         SYSCALL_YIELD => sys_yield(),
+        SYSCALL_GET_TIME => sys_get_time(),
         _ => panic!("Unsupported syscall_id: {}", syscall_id),
     }
 }

ch3/os/src/syscall/process.rs

@@ -2,6 +2,7 @@
 // use crate::batch::run_next_app;
 use crate::println;
 use crate::task::{exit_current_and_run_next, suspend_current_and_run_next};
+use crate::timer::get_time_ms;
 
 /// 任务退出, 并立即切换任务
 pub fn sys_exit(exit_code: i32) -> ! {
@@ -14,3 +15,7 @@ pub fn sys_yield() -> isize {
     suspend_current_and_run_next();
     0
 }
+
+pub fn sys_get_time() -> isize {
+    get_time_ms() as isize
+}

ch3/os/src/timer.rs

@@ -0,0 +1,29 @@
+
+use riscv::register::time;
+use crate::config::CLOCK_FREQ;
+use crate::sbi::set_timer;
+
+const TICKS_PER_SEC: usize = 100;
+const MICRO_PER_SEC: usize = 1_000_000;
+const MSEC_PER_SEC: usize = 1_000;
+
+//
+pub fn get_time() -> usize {
+    time::read()
+}
+
+// 读取mtime的值, 然后使用 (当前每秒的频率 / TICKS_PER_SEC 100) = 得到 10ms的数值的增量, 相加得到下一个下10ms 后mtime应该属于的值
+// 并设置mtimecmp, 这样在10ms后就会发出一个S特权的时钟中断
+pub fn set_next_trigger() {
+    set_timer(get_time() + CLOCK_FREQ / TICKS_PER_SEC);
+}
+
+// 以微秒为单位, 返回当前计数器经过的微秒
+// 当前 (计时器的值的总数 / 频率) = 计时器中经过了多少秒,    (计时器的值的总数 / 频率) * 1_000_000 得到微秒(1秒有1_000_000微秒)
+pub fn get_time_us() -> usize {
+    time::read() / (CLOCK_FREQ / MICRO_PER_SEC)
+}
+
+pub fn get_time_ms() -> usize {
+    time::read() / (CLOCK_FREQ / MSEC_PER_SEC)
+}

ch3/os/src/trap/mod.rs

@@ -1,15 +1,14 @@
 mod context;
 
 use core::arch::global_asm;
-use riscv::register::{
-    mtvec::TrapMode,
-    scause::{self, Exception, Trap},
-    stval, stvec,
-};
+use riscv::register::{mtvec::TrapMode, scause::{self, Exception, Trap}, sie, stval, stvec};
+use riscv::register::scause::Interrupt;
+
 pub use context::TrapContext;
-// use crate::batch::run_next_app;
 use crate::println;
 use crate::syscall::syscall;
+use crate::task::{exit_current_and_run_next, suspend_current_and_run_next};
+use crate::timer::set_next_trigger;
 
 
 
@@ -26,6 +25,12 @@ pub fn init() {
     }
 }
 
+// 设置riscv 允许定时器中断
+pub fn enable_timer_interrupt() {
+    unsafe {
+        sie::set_stimer();
+    }
+}
 
 // 这个函数是 trap.S 中__alltraps 保存完所有寄存器在内核栈 之后会进入到这里
 #[no_mangle]
@@ -43,12 +48,19 @@ pub fn trap_handler(trap_context: &mut TrapContext) -> &mut TrapContext {
         // 访问不允许的内存
         Trap::Exception(Exception::StoreFault) | Trap::Exception(Exception::StorePageFault) => {
             println!("[kernel] PageFault in application, kernel killed it.");
-            // run_next_app();
+            exit_current_and_run_next();
         }
         // 非法指令
         Trap::Exception(Exception::IllegalInstruction) => {
             println!("[kernel] IllegalInstruction in application, kernel killed it.");
-            // run_next_app();
+            exit_current_and_run_next();
+        }
+        Trap::Interrupt(Interrupt::SupervisorTimer) => {
+            println!("Clock interrupt Clock interrupt Clock interrupt Clock interrupt");
+            // 发生时钟中断之后, 继续设置下一个时钟中断的发起时间
+            set_next_trigger();
+            // 暂停当前任务, 切换新的任务
+            suspend_current_and_run_next();
         }
         // 未知错误
         _ => {