def __init__(self, ram, os, num=0):
threading.Thread.__init__(self)
self._num = num # unique ID of this cpu
self.clear_registers()
self._ram = ram
self._os = os
self._debug = False
self._intr_raised = False
self._intr_addrs = set()
self._intr_lock = threading.Lock()
self._intr_vector = [self._timer_isr]
# Create device controller threads.
# This is done here so that when the CPU is done running a program,
# the screen and kbd threads can be killed. Then if it is told
# to start up again, it will create new threads (since you cannot
# restart stopped threads).
# TODO: revisit the above decision? CPU thread is not stopped anymore...
# Also, not using the Keyboard and Screen devices...
# And, it seems weird for the CPU to start up the other device controllers...
import devices
self._timer = devices.TimerController(self, TIMER_DEV_ID, self._debug)
self._os.set_timer_controller(self._timer)
# Start up the thread, though its countdown will be -1, so it won't do anything
# until that is set.
self._timer.start()
def __init__(self, ram, os, num=0):
# TODO: the CPU should know nothing about the OS. The CPU should
# just execute instructions and handle the interrupts. We should
# not pass the OS object in, but instead should make an API which
# the OS code could call to register a callback to be called for
# the various interrupts -- the software trap, timer expiration,
# etc.
self._num = num # unique ID of this cpu
self._registers = {
'reg0' : 0,
'reg1' : 0,
'reg2' : 0,
'pc': 0
}
self._ram = ram
self._os = os
self._mmu = MMU(self._ram)
self._debug = False
# Set _stop to True to "power down" the CPU.
self._stop = False
self._intr_raised = False
self._intr_addrs = set()
self._intr_lock = threading.Lock()
self._intr_vector = [self._trap_isr,
self._timer_isr]
# Create device controller threads.
# This is done here so that when the CPU is done running a program,
# the screen and kbd threads can be killed. Then if it is told
# to start up again, it will create new threads (since you cannot
# restart stopped threads).
# TODO: revisit the above decision? CPU thread is not stopped anymore...
# Also, not using the Keyboard and Screen devices...
# And, it seems weird for the CPU to start up the other device controllers...
import devices
self._timer = devices.TimerController(self, TIMER_DEV_ID, self._debug)
# Start up the thread, though its countdown will be -1, so it won't do
# anything until that is set.
self._timer.start()
