EXTERN stack
EXTERN stack2
EXTERN func
GLOBAL dummy_int_handler
GLOBAL dummy_err_handler
GLOBAL thread_int_handler
GLOBAL start
GLOBAL cont

yield:
mov [stack2], esp
mov esp, [stack]
ret

dummy_int_handler:
iret

dummy_err_handler:
add esp, 4
iret

thread_int_handler:
push eax
push ebx
push ecx
push edx
push esi
push edi
push ebp
push ds
push es
push fs
push gs
mov al, 0x20
out 0x20, al
call yield
pop gs
pop fs
pop es
pop ds
pop ebp
pop edi
pop esi
pop edx
pop ecx
pop ebx
pop eax
iret

start:
mov [stack], esp
mov esp, [stack2]
sti
jmp func

cont:
mov [stack], esp
mov esp, [stack2]
sti
ret