write kernel sp to tss in dispatcher

kernel/thread/dispatcher.cc

@@ -1,6 +1,8 @@
 // vim: set noet ts=4 sw=4:
 
 #include "dispatcher.h"
+#include "../arch/tss.h"
+#include "thread.h"
 
 #include "../arch/core.h"
 #include "../debug/output.h"  // IWYU pragma: keep
@@ -12,6 +14,7 @@ Thread *Dispatcher::active() const { return life; }
 void Dispatcher::go(Thread *first) {
 	assert(active() == nullptr);
 	setActive(first);
+	mytss.sp0 = first->StackPointer.isr;
 	first->go();
 }
 
@@ -20,7 +23,7 @@ void Dispatcher::dispatch(Thread *next) {
 	assert(current != nullptr);
 	if (current != next) {
 		setActive(next);
-
+		mytss.sp0 = next->StackPointer.isr;
 		current->resume(next);
 	}
 }