def test_write_AbsoluteX():
address_mode = AbsoluteX
cpu = CPU()
memory = Memory(rom=[0x30, 0x01, 0xFF, 0x02, 0x0A, 0x05], ram=list(map(lambda x: x % 256, range(Memory.ram_size()))))
cpu.inc_cycle_by(-cpu.cycle)
cpu.inc_pc_by(-cpu.pc + MemoryPositions.PRG_ROM_START.start)
cpu.x = 0x25
address = address_mode.fetch_address(cpu, memory)
address_mode.write_to(cpu, memory, address, 20)
assert address == 0x0155
assert memory.ram[address] == 20
cpu.inc_cycle_by(-cpu.cycle)
cpu.x = 0x30
address = address_mode.fetch_address(cpu, memory)
address_mode.write_to(cpu, memory, address, 100)
assert address == 0x032F
assert memory.ram[address] == 100
cpu.inc_cycle_by(-cpu.cycle)
cpu.x = 0x20
address = address_mode.fetch_address(cpu, memory)
address_mode.write_to(cpu, memory, address, 67)
assert address == 0x052A
assert memory.ram[address] == 67
def test_read_AbsoluteX():
address_mode = AbsoluteX
cpu = CPU()
memory = Memory(rom=[0x32, 0x02, 0x7F, 0x01, 0x00, 0x20], ram=list(map(lambda x: x % 256, range(Memory.ram_size()))))
cpu.inc_cycle_by(-cpu.cycle)
cpu.inc_pc_by(-cpu.pc + MemoryPositions.PRG_ROM_START.start)
cpu.x = 0x0A
address = address_mode.fetch_address(cpu, memory)
value = address_mode.read_from(cpu, memory, address)
assert address == 0x023C
assert value == (0x023C % 256)
cpu.inc_cycle_by(-cpu.cycle)
cpu.x = 0xA1
address = address_mode.fetch_address(cpu, memory)
value = address_mode.read_from(cpu, memory, address)
assert address == 0x0220
assert value == (0x0220 % 256)
cpu.inc_cycle_by(-cpu.cycle)
cpu.x = 0x07
address = address_mode.fetch_address(cpu, memory)
value = address_mode.read_from(cpu, memory, address)
assert address == 0x2007
def test_read_Absolute():
address_mode = Absolute
cpu = CPU()
memory = Memory(rom=[0x32, 0x02, 0x7F, 0x01, 0xFF, 0x07],
ram=list(map(lambda x: x % 256, range(Memory.ram_size()))))
cpu.inc_cycle_by(-cpu.cycle)
cpu.inc_pc_by(-cpu.pc + MemoryPositions.PRG_ROM_START.start)
address = address_mode.fetch_address(cpu, memory)
value = address_mode.read_from(cpu, memory, address)
assert address == 0x0232
assert value == (0x0232 % 256)
assert cpu.cycle == 3
cpu.inc_cycle_by(-cpu.cycle)
address = address_mode.fetch_address(cpu, memory)
value = address_mode.read_from(cpu, memory, address)
assert address == 0x017F
assert value == (0x017F % 256)
assert cpu.cycle == 3
cpu.inc_cycle_by(-cpu.cycle)
address = address_mode.fetch_address(cpu, memory)
value = address_mode.read_from(cpu, memory, address)
assert address == 0x07FF
assert value == (0x07FF % 256)
assert cpu.cycle == 3
def test_write_Absolute():
address_mode = Absolute
cpu = CPU()
memory = Memory(rom=[0x30, 0x01, 0xFF, 0x02, 0x0A, 0x05],
ram=list(map(lambda x: x % 256, range(Memory.ram_size()))))
cpu.inc_cycle_by(-cpu.cycle)
cpu.inc_pc_by(-cpu.pc + MemoryPositions.PRG_ROM_START.start)
address = address_mode.fetch_address(cpu, memory)
address_mode.write_to(cpu, memory, address, 50)
assert address == 0x0130
assert memory.ram[address] == 50
assert cpu.cycle == 3
cpu.inc_cycle_by(-cpu.cycle)
address = address_mode.fetch_address(cpu, memory)
address_mode.write_to(cpu, memory, address, 100)
assert address == 0x02FF
assert memory.ram[address] == 100
assert cpu.cycle == 3
cpu.inc_cycle_by(-cpu.cycle)
address = address_mode.fetch_address(cpu, memory)
address_mode.write_to(cpu, memory, address, 67)
assert address == 0x050A
assert memory.ram[address] == 67
assert cpu.cycle == 3
def test_write_ZeroPageX():
address_mode = ZeroPageX
cpu = CPU()
memory = Memory(rom=list(range(256)))
cpu.inc_cycle_by(-cpu.cycle)
cpu.inc_pc_by(-cpu.pc + MemoryPositions.PRG_ROM_START.start)
cpu.x = 5
address = address_mode.fetch_address(cpu, memory)
address_mode.write_to(cpu, memory, address, 6)
assert address == 5
assert memory.ram[address] == 6
assert cpu.cycle == 3
cpu.inc_cycle_by(-cpu.cycle)
cpu.inc_pc_by(-cpu.pc + MemoryPositions.PRG_ROM_START.start + 20)
cpu.x = 15
address = address_mode.fetch_address(cpu, memory)
address_mode.write_to(cpu, memory, address, 105)
assert address == 35
assert memory.ram[address] == 105
assert cpu.cycle == 3
cpu.inc_cycle_by(-cpu.cycle)
cpu.inc_pc_by(-cpu.pc + MemoryPositions.PRG_ROM_START.start + 100)
cpu.x = 155
address = address_mode.fetch_address(cpu, memory)
address_mode.write_to(cpu, memory, address, 143)
assert address == 255
assert memory.ram[address] == 143
assert cpu.cycle == 3
cpu.inc_cycle_by(-cpu.cycle)
cpu.inc_pc_by(-cpu.pc + MemoryPositions.PRG_ROM_START.start + 255)
cpu.x = 0
address = address_mode.fetch_address(cpu, memory)
address_mode.write_to(cpu, memory, address, 255)
assert address == 255
assert memory.ram[address] == 255
assert cpu.cycle == 3
cpu.inc_cycle_by(-cpu.cycle)
cpu.inc_pc_by(-cpu.pc + MemoryPositions.PRG_ROM_START.start + 255)
cpu.x = 75
address = address_mode.fetch_address(cpu, memory)
address_mode.write_to(cpu, memory, address, 255)
assert address == 74
assert memory.ram[address] == 255
assert cpu.cycle == 3
def test_read_ZeroPageX():
address_mode = ZeroPageX
cpu = CPU()
memory = Memory(rom=list(range(256)), ram=list(reversed(range(256))))
cpu.inc_cycle_by(-cpu.cycle)
cpu.inc_pc_by(-cpu.pc + MemoryPositions.PRG_ROM_START.start)
cpu.x = 1
address = address_mode.fetch_address(cpu, memory)
value = address_mode.read_from(cpu, memory, address)
assert address == 1
assert value == 254
assert cpu.cycle == 3
cpu.inc_cycle_by(-cpu.cycle)
cpu.inc_pc_by(-cpu.pc + MemoryPositions.PRG_ROM_START.start + 20)
cpu.x = 10
address = address_mode.fetch_address(cpu, memory)
value = address_mode.read_from(cpu, memory, address)
assert address == 30
assert value == 225
assert cpu.cycle == 3
cpu.inc_cycle_by(-cpu.cycle)
cpu.inc_pc_by(-cpu.pc + MemoryPositions.PRG_ROM_START.start + 100)
cpu.x = 5
address = address_mode.fetch_address(cpu, memory)
value = address_mode.read_from(cpu, memory, address)
assert address == 105
assert value == 150
assert cpu.cycle == 3
cpu.inc_cycle_by(-cpu.cycle)
cpu.inc_pc_by(-cpu.pc + MemoryPositions.PRG_ROM_START.start + 255)
cpu.x = 0
address = address_mode.fetch_address(cpu, memory)
value = address_mode.read_from(cpu, memory, address)
assert address == 255
assert value == 0
assert cpu.cycle == 3
cpu.inc_cycle_by(-cpu.cycle)
cpu.inc_pc_by(-cpu.pc + MemoryPositions.PRG_ROM_START.start + 255)
cpu.x = 5
address = address_mode.fetch_address(cpu, memory)
value = address_mode.read_from(cpu, memory, address)
assert address == 4
assert value == 251
assert cpu.cycle == 3
def test_read_ZeroPage():
address_mode = ZeroPage
cpu = CPU()
memory = Memory(rom=list(range(256)), ram=list(reversed(range(256))))
cpu.inc_cycle_by(-cpu.cycle)
cpu.inc_pc_by(-cpu.pc + MemoryPositions.PRG_ROM_START.start)
address = address_mode.fetch_address(cpu, memory)
value = address_mode.read_from(cpu, memory, address)
assert address == 0
assert value == 255
cpu.inc_cycle_by(-cpu.cycle)
cpu.inc_pc_by(-cpu.pc + MemoryPositions.PRG_ROM_START.start + 20)
address = address_mode.fetch_address(cpu, memory)
value = address_mode.read_from(cpu, memory, address)
assert address == 20
assert value == 235
cpu.inc_cycle_by(-cpu.cycle)
cpu.inc_pc_by(-cpu.pc + MemoryPositions.PRG_ROM_START.start + 100)
address = address_mode.fetch_address(cpu, memory)
value = address_mode.read_from(cpu, memory, address)
assert address == 100
assert value == 155
cpu.inc_cycle_by(-cpu.cycle)
cpu.inc_pc_by(-cpu.pc + MemoryPositions.PRG_ROM_START.start + 255)
address = address_mode.fetch_address(cpu, memory)
value = address_mode.read_from(cpu, memory, address)
assert address == 255
assert value == 0
def test_read_Accumulator():
address_mode = Accumulator
cpu = CPU()
memory = Memory()
cpu.a = 0x00
cpu.inc_cycle_by(-cpu.cycle)
address = address_mode.fetch_address(cpu, memory)
value = address_mode.read_from(cpu, memory, address)
assert address is None
assert value == 0x00
cpu.inc_cycle_by(-cpu.cycle)
cpu.inc_pc_by(-cpu.pc)
cpu.inc_pc_by(MemoryPositions.PRG_ROM_START.start)
cpu.a = 0x10
address = address_mode.fetch_address(cpu, memory)
value = address_mode.read_from(cpu, memory, address)
assert address is None
assert value == 0x10
cpu.inc_cycle_by(-cpu.cycle)
cpu.inc_pc_by(-cpu.pc)
cpu.inc_pc_by(MemoryPositions.PRG_ROM_START.start)
cpu.a = 0xFF
address = address_mode.fetch_address(cpu, memory)
value = address_mode.read_from(cpu, memory, address)
assert address is None
assert value == 0xFF
def test_read_Accumulator():
address_mode = Accumulator
cpu = CPU()
memory = Memory()
cpu.inc_cycle_by(-cpu.cycle)
address = address_mode.fetch_address(cpu, memory)
address_mode.write_to(cpu, memory, address, 5)
assert address is None
assert cpu.a == 5
cpu.inc_cycle_by(-cpu.cycle)
cpu.inc_pc_by(-cpu.pc)
cpu.inc_pc_by(MemoryPositions.PRG_ROM_START.start)
cpu.a = 0x10
address = address_mode.fetch_address(cpu, memory)
address_mode.write_to(cpu, memory, address, 105)
assert address is None
assert cpu.a == 105
cpu.inc_cycle_by(-cpu.cycle)
cpu.inc_pc_by(-cpu.pc)
cpu.inc_pc_by(MemoryPositions.PRG_ROM_START.start)
cpu.a = 0xFF
address = address_mode.fetch_address(cpu, memory)
address_mode.write_to(cpu, memory, address, 255)
assert address is None
assert cpu.a == 255
def test_read_IndirectY():
address_mode = IndirectY
cpu = CPU()
memory = Memory(rom=[0x00, 0x02, 0x7F, 0x01, 0xFF, 0x07],
ram=list(map(lambda x: x % 256, range(Memory.ram_size()))))
cpu.inc_cycle_by(-cpu.cycle)
cpu.inc_pc_by(-cpu.pc + MemoryPositions.PRG_ROM_START.start)
cpu.y = 4
address = address_mode.fetch_address(cpu, memory)
value = address_mode.read_from(cpu, memory, address)
assert address == 0x0104
assert value == address % 256
cpu.inc_cycle_by(-cpu.cycle)
cpu.y = 0xFF
address = address_mode.fetch_address(cpu, memory)
value = address_mode.read_from(cpu, memory, address)
assert address == 0x0401
assert value == address % 256
def test_write_IndirectY():
address_mode = IndirectY
cpu = CPU()
memory = Memory(rom=[0x00, 0x02, 0x7F, 0x01, 0xFF, 0x07],
ram=list(map(lambda x: x % 256, range(Memory.ram_size()))))
cpu.inc_cycle_by(-cpu.cycle)
cpu.inc_pc_by(-cpu.pc + MemoryPositions.PRG_ROM_START.start)
cpu.y = 4
address = address_mode.fetch_address(cpu, memory)
address_mode.write_to(cpu, memory, address, 9)
assert address == 0x0104
assert memory.ram[address] == 9
cpu.inc_cycle_by(-cpu.cycle)
cpu.y = 0xFF
address = address_mode.fetch_address(cpu, memory)
address_mode.write_to(cpu, memory, address, 50)
assert address == 0x0401
assert memory.ram[address] == 50
def test_read_IndirectX():
address_mode = IndirectX
cpu = CPU()
memory = Memory(rom=[0x00, 0x02, 0x7F, 0x01, 0xFF, 0x07],
ram=list(map(lambda x: x % 256, range(Memory.ram_size()))))
cpu.inc_cycle_by(-cpu.cycle)
cpu.inc_pc_by(-cpu.pc + MemoryPositions.PRG_ROM_START.start)
cpu.x = 4
address = address_mode.fetch_address(cpu, memory)
value = address_mode.read_from(cpu, memory, address)
assert address == (((0x0504 + 1) % 256) << 8 | (0x0504 % 256))
assert value == address % 256
assert cpu.cycle == 5
cpu.inc_cycle_by(-cpu.cycle)
cpu.x = 0xFF
address = address_mode.fetch_address(cpu, memory)
value = address_mode.read_from(cpu, memory, address)
assert address == (((0x0201 + 1) % 256) << 8 | (0x0201 % 256))
assert value == address % 256
assert cpu.cycle == 5
def test_Indirect():
address_mode = Indirect
cpu = CPU()
memory = Memory(rom=[0x32, 0x02, 0x7F, 0x01, 0xFF, 0x07],
ram=list(map(lambda x: x % 256, range(Memory.ram_size()))))
cpu.inc_cycle_by(-cpu.cycle)
cpu.inc_pc_by(-cpu.pc + MemoryPositions.PRG_ROM_START.start)
address = address_mode.fetch_address(cpu, memory)
assert address == (((0x0232 + 1) % 256) << 8 | (0x0232 % 256))
assert cpu.cycle == 4
cpu.inc_cycle_by(-cpu.cycle)
address = address_mode.fetch_address(cpu, memory)
assert address == (((0x017F + 1) % 256) << 8 | (0x017F % 256))
assert cpu.cycle == 4
cpu.inc_cycle_by(-cpu.cycle)
address = address_mode.fetch_address(cpu, memory)
assert address == (((0x07FF + 1) % 256) << 8 | (0x07FF % 256))
assert cpu.cycle == 4
def emulate(file_path):
nestest_log_format = args.nestest
automation_mode = args.automation
running = True
file_contents = read_file(file_path)
cartridge = Cartridge.from_bytes(file_contents)
ppu = PPU(cartridge.chr_rom, mirroring=cartridge.header.flags_6&0b00000001)
memory = Memory(cartridge.prg_rom,ppu=ppu)
cpu = CPU(log_compatible_mode=nestest_log_format)
ppu.setNMI(cpu,memory,NMI)
reset_pos_low = memory.fetch(MemoryPositions.RESET.start)
reset_pos_high = memory.fetch(MemoryPositions.RESET.end)
reset_pos = MemoryPositions.PRG_ROM_START.wrap(
AddressMode.get_16_bits_addr_from_high_low((reset_pos_high << 8) & HIGH_BITS_MASK, reset_pos_low & LOW_BITS_MASK))
cpu.pc = reset_pos
if nestest_log_format:
# hack for Nintendulator nestest log comparison
cpu.flags = 0x24
cpu.inc_cycle_by(7)
if automation_mode:
cpu.pc = MemoryPositions.PRG_ROM_START.start
i = 0
line = 0
while running:
try:
previous_state = CPUState(pc=cpu.pc, sp=cpu.sp, a=cpu.a, x=cpu.x, y=cpu.y, p=StatusRegisterFlags(int_value=cpu.flags), addr=cpu.addr, data=cpu.data,
cycle=cpu.cycle, log_compatible_mode=nestest_log_format)
if previous_state.pc == 0xC66E:
# TODO: remove, this is a breakpoint for debugging
aaaa = ""
ppu.reloadControllers()#reloads controllers every tick
i+=1
if (i==114):
ppu.scanLine(line)
i=0
line+=1
if line==262:
line=0
decoded = cpu.exec_in_cycle(fetch_and_decode_instruction, cpu, memory) # fetching and decoding a instruction always take 1 cycle
if decoded:
decoded.exec(cpu, memory)
if isinstance(decoded, BRK):
# abort program on BRK
running = False
print("Break")
break
#print_debug_line(cpu, previous_state, decoded, nestest_log_format)
cpu.clear_state_mem()
except IndexError as e:
# we've reached a program counter that is not within memory bounds
print(e)
running = False
except KeyError as e:
# print("Can't find instruction by code {}".format(e))
cpu.inc_pc_by(1)
except Exception as e:
print(e)
cpu.inc_pc_by(1)
def test_Immediate():
address_mode = Immediate
cpu = CPU()
memory = Memory(rom=[0x00])
cpu.inc_cycle_by(-cpu.cycle)
cpu.inc_pc_by(-cpu.pc)
cpu.inc_pc_by(MemoryPositions.PRG_ROM_START.start)
address = address_mode.fetch_address(cpu, memory)
value = address_mode.read_from(cpu, memory, address)
assert address == 0x00
assert value == 0x00
cpu.inc_cycle_by(-cpu.cycle)
cpu.inc_pc_by(-cpu.pc)
cpu.inc_pc_by(MemoryPositions.PRG_ROM_START.start)
memory.rom[0] = 0x10
address = address_mode.fetch_address(cpu, memory)
value = address_mode.read_from(cpu, memory, address)
assert address == 0x10
assert value == 0x10
cpu.inc_cycle_by(-cpu.cycle)
cpu.inc_pc_by(-cpu.pc)
cpu.inc_pc_by(MemoryPositions.PRG_ROM_START.start)
memory.rom[0] = 0xFF
address = address_mode.fetch_address(cpu, memory)
value = address_mode.read_from(cpu, memory, address)
assert address == 0xFF
assert value == 0xFF