Baekalfen · Baekalfen · Sep 15, 2022 · Sep 15, 2022 · May 21, 2025 · May 20, 2025
diff --git a/pyboy/__main__.py b/pyboy/__main__.py
@@ -107,6 +107,14 @@ def valid_sample_rate(freq):
     help="Add GameShark cheats on start-up. Add multiple by comma separation (i.e. '010138CD, 01033CD1')",
 )
 
+parser.add_argument("--serial-bind", action="store_true", help="Bind to this TCP addres for using Link Cable")
+parser.add_argument(
+    "--serial-address", default=None, type=str, help="Connect (or bind) to this TCP address for using Link Cable"
+)
+parser.add_argument(
+    "--serial-interrupt-based", action="store_true", help="Use only interrupt-based transfers for using Link Cable"
+)
+
 gameboy_type_parser = parser.add_mutually_exclusive_group()
 gameboy_type_parser.add_argument(
     "--dmg", action="store_const", const=False, dest="cgb", help="Force emulator to run as original Game Boy (DMG)"
@@ -160,6 +168,9 @@ def valid_sample_rate(freq):
 def main():
     argv = parser.parse_args()
 
+    if (argv.serial_bind or argv.serial_interrupt_based) and not argv.serial_address:
+        parser.error("--serial-bind and --serial-interrupt-based requires --serial-address")
+
     print(
         """
 The Game Boy controls are as follows:

diff --git a/pyboy/core/cartridge/cartridge.py b/pyboy/core/cartridge/cartridge.py
@@ -53,7 +53,7 @@ def load_romfile(filename):
 
     logger.debug("Loading ROM file: %d bytes", len(romdata))
     if len(romdata) == 0:
-        logger.error("ROM file is empty!")
+        logger.critical("ROM file is empty!")
         raise PyBoyException("Empty ROM file")
 
     banksize = 16 * 1024

diff --git a/pyboy/core/cartridge/mbc1.py b/pyboy/core/cartridge/mbc1.py
@@ -47,7 +47,7 @@ def setitem(self, address, value):
     def getitem(self, address):
         if 0xA000 <= address < 0xC000:
             if not self.rambank_initialized:
-                logger.error("RAM banks not initialized: %0.4x", address)
+                logger.warning("RAM banks not initialized: %0.4x", address)
 
             if not self.rambank_enabled:
                 return 0xFF

diff --git a/pyboy/core/cartridge/mbc2.py b/pyboy/core/cartridge/mbc2.py
@@ -34,7 +34,7 @@ def getitem(self, address):
             return self.rombanks[self.rombank_selected, address - 0x4000]
         elif 0xA000 <= address < 0xC000:
             if not self.rambank_initialized:
-                logger.error("RAM banks not initialized: %0.4x", address)
+                logger.warning("RAM banks not initialized: %0.4x", address)
 
             if not self.rambank_enabled:
                 return 0xFF

diff --git a/pyboy/core/cartridge/rtc.py b/pyboy/core/cartridge/rtc.py
@@ -22,7 +22,7 @@ def __init__(self, filename):
         self.halt = 0
 
         if not os.path.exists(self.filename):
-            logger.info("No RTC file found. Skipping.")
+            logger.debug("No RTC file found. Skipping.")
         else:
             with open(self.filename, "rb") as f:
                 self.load_state(IntIOWrapper(f), STATE_VERSION)

diff --git a/pyboy/core/mb.py b/pyboy/core/mb.py
@@ -9,8 +9,8 @@
     PyBoyException,
     PyBoyOutOfBoundsException,
     INTR_TIMER,
-    INTR_SERIAL,
     INTR_HIGHTOLOW,
+    INTR_SERIAL,
     OPCODE_BRK,
     MAX_CYCLES,
 )
@@ -32,9 +32,12 @@ def __init__(
         sound_sample_rate,
         cgb,
         randomize=False,
+        serial_address=None,
+        serial_bind=None,
+        serial_interrupt_based=False,
     ):
         if bootrom_file is not None:
-            logger.info("Boot-ROM file provided")
+            logger.debug("Boot-ROM file provided")
 
         self.cartridge = cartridge.load_cartridge(gamerom)
         logger.debug("Cartridge started:\n%s", str(self.cartridge))
@@ -49,7 +52,7 @@ def __init__(
             logger.debug("Cartridge type auto-detected to %s", ("CGB" if self.cartridge.cgb else "DMG"))
 
         self.timer = timer.Timer()
-        self.serial = serial.Serial()
+        self.serial = serial.Serial(serial_address, serial_bind, serial_interrupt_based)
         self.interaction = interaction.Interaction()
         self.ram = ram.RAM(cgb, randomize=randomize)
         self.cpu = cpu.CPU(self)
@@ -228,6 +231,7 @@ def buttonevent(self, key):
 
     def stop(self, save):
         self.sound.stop()
+        self.serial.stop()
         if save:
             self.cartridge.stop()
 
@@ -394,6 +398,9 @@ def getitem(self, i):
                 if self.serial.tick(self.cpu.cycles):
                     self.cpu.set_interruptflag(INTR_SERIAL)
                 if i == 0xFF01:
+                    # logger.debug(("Master " if self.serial.is_master else "Slave ") + "Read SB: %02x", self.serial.SB)
+                    assert self.serial.sending_state == 2  # PASSIVE
+                    assert self.serial.SC & 0x80 == 0  # No transfer active
                     return self.serial.SB
                 elif i == 0xFF02:
                     return self.serial.SC

diff --git a/pyboy/core/serial.pxd b/pyboy/core/serial.pxd
@@ -3,27 +3,37 @@
 # GitHub: https://github.com/Baekalfen/PyBoy
 #
 
+cimport cython
 from libc.stdint cimport int64_t, uint8_t, uint16_t, uint32_t, uint64_t
 
+from pyboy.logging.logging cimport Logger
 from pyboy.utils cimport IntIOInterface
 
-import cython
-
-from pyboy.logging.logging cimport Logger
 
 cdef uint64_t MAX_CYCLES, CYCLES_8192HZ
 cdef Logger logger
 
+cdef uint64_t SENDING, RECEIVING, PASSIVE
+
 cdef class Serial:
     cdef uint64_t SB, SC
     cdef int64_t _cycles_to_interrupt
     cdef uint64_t last_cycles, clock, clock_target
     cdef bint transfer_enabled, double_speed, internal_clock
+    cdef bint serial_connected, is_master
+    cdef uint64_t sending_state
 
     cdef bint tick(self, uint64_t) noexcept nogil
+    cdef void stop(self) noexcept
 
     cdef void set_SB(self, uint8_t) noexcept nogil
     cdef void set_SC(self, uint8_t) noexcept nogil
 
     cdef int save_state(self, IntIOInterface) except -1
     cdef int load_state(self, IntIOInterface, int) except -1
+
+    cdef object connection, binding_connection
+    cdef uint8_t trans_bits
+    cdef bint serial_interrupt_based
+
+    cdef void disconnect(self) noexcept nogil