diff --git a/zion/interrupt/interrupt.cpp b/zion/interrupt/interrupt.cpp
index e5665b5..88f38cb 100644
--- a/zion/interrupt/interrupt.cpp
+++ b/zion/interrupt/interrupt.cpp
@@ -4,6 +4,7 @@
 
 #include "common/port.h"
 #include "debug/debug.h"
+#include "scheduler/scheduler.h"
 
 #define IDT_INTERRUPT_GATE 0x8E
 
@@ -122,6 +123,7 @@ extern "C" void interrupt_timer(InterruptFrame*) {
     dbgln("timer: %us", cnt * 50 / 1000);
   }
   outb(PIC1_COMMAND, PIC_EOI);
+  sched::Yield();
 }
 
 void EnablePic() {
diff --git a/zion/zion.cpp b/zion/zion.cpp
index 503bc56..1b1b4af 100644
--- a/zion/zion.cpp
+++ b/zion/zion.cpp
@@ -12,22 +12,31 @@
 #include "syscall/syscall.h"
 
 extern "C" void zion() {
+  dbgln("[boot] Init GDT & IDT.");
   InitGdt();
   InitIdt();
+
+  dbgln("[boot] Init Paging.");
   InitPaging();
 
+  dbgln("[boot] Init Physical Memory Manager.");
   phys_mem::InitBootstrapPageAllocation();
   KernelHeap heap(0xFFFFFFFF'40000000, 0xFFFFFFFF'80000000);
   phys_mem::InitPhysicalMemoryManager();
 
+  dbgln("[boot] Init syscalls.");
   InitSyscall();
 
+  dbgln("[boot] Init scheduler.");
   // Schedule every 50ms.
   SetFrequency(/* hertz= */ 20);
   sched::InitScheduler();
-  sched::EnableScheduler();
 
+  dbgln("[boot] Loading sys init program.");
   LoadInitProgram();
+
+  dbgln("[boot] Init finished, yielding.");
+  sched::EnableScheduler();
   sched::Yield();
 
   dbgln("Sleeping!");