Feat: lab 3 w/o adv 2

kernel/include/timer.h

@@ -0,0 +1,27 @@
+#pragma once
+
+#include <stddef.h>
+
+typedef void (*task_callback_func_t)(uint64_t);
+
+typedef struct {
+  uint64_t firing_tick;
+  uint64_t interval;
+  uint64_t repeat;
+
+  task_callback_func_t func;
+  uint64_t param;
+} task_t;
+
+typedef struct timer {
+  struct timer *_l, *_r;
+  uint32_t _d;
+
+  task_t data;
+} timer_t;
+
+void add_task(task_t task);
+
+void timer_irq_handler(void);
+
+extern timer_t *global_timer;