Feat: kernel thread done

kernel/lib/timer.c

@@ -3,6 +3,7 @@
 #include <logger.h>
 #include <utils.h>
 #include <kmalloc.h>
+#include <thread.h>
 
 #define CORE0_TIMER_IRQ_CTRL ((volatile uint32_t *)0x40000040)
 
@@ -92,6 +93,21 @@ void add_timer_task(task_t task)
   _check_enable_timer();
 }
 
+void sleep(uint64_t ms)
+{
+  uint64_t cntpct_el0, cntfrq_el0;
+  R_SYSREG(cntpct_el0, cntpct_el0);
+  R_SYSREG(cntfrq_el0, cntfrq_el0);
+
+  uint64_t wake = cntpct_el0 + cntfrq_el0 * ms / 1000000;
+  for (;;) {
+    R_SYSREG(cntpct_el0, cntpct_el0);
+    if (cntpct_el0 >= wake)
+      break;
+    yield();
+  }
+}
+
 typedef struct {
   interrupt_callback_func_t func;
   uint64_t param;