calls, jumps, and stack.

include/cpu.h

@@ -50,4 +50,6 @@ void cpu_set_reg(reg_type rt, u16 val);
 void fetch_data();
 
 u8 cpu_get_ie_register();
-void cpu_set_ie_register(u8 ie);
+void cpu_set_ie_register(u8 ie);
+
+cpu_registers *cpu_get_regs();

include/stack.h

@@ -0,0 +1,9 @@
+#pragma once
+
+#include <common.h>
+
+void stack_push(u8 data);
+void stack_push16(u16 data);
+
+u8 stack_pop();
+u16 stack_pop16();