kernel threads

kernel threads and preemptive multitasking

src/arch/x86_64/kstack.c

@@ -0,0 +1,8 @@
+#include <arch/kstack.h>
+#include <arch/ist.h>
+#include <arch/cls.h>
+
+void arch_setkernelstack(void* stack){
+	
+	arch_getcls()->ist.rsp0 = (uint64_t)stack;
+}