netdimmutils 0.5.4

Code libraries for working with a SEGA Net Dimm

netdimm

Collection of routines written in Python for remotely controlling a SEGA Net Dimm attached to a Naomi, Triforce or Chihiro system. Originally based off of the old triforcetools.py script floating around the web, this has been upgraded to Python 3, fully typed and massively improved. It requires a minimum of Python 3.6 to operate.

NetDimm

The NetDimm class provides high-level access to a net dimm accessible from the network. It handles uploading and downloading data, querying status and changing modes of the net dimm.

Default Constructor

Takes a single string containing thet IP of the net dimm you wish to connect to and manages that connection. All query and update methods found in this class can be called directly and they will connect to the net dimm, perform their action and then disconnect. However, it can be faster to maintain that connection. For that, see the connection() context manager below. Optionally, the second argument (or keyword argument) version can be given. This is a NetDimmVersionEnum which allows you to set the version of the net dimm you are talking to. This matters in a few rare cases. Optionally, the third argument (or keyword argument) target can be given. This is a NetDimmTargetEnum which allows you to set the target the net dimm is talking to. This matters for default timeouts. Optionally, the forth argument (or keyword argument) log can be given. This can either be a function in the form of log(msg: str, *, newline: bool = True) -> None or it can be given the print function. In either case, if this is provided, various verbose information will be logged. Optionally, the firth argument (or keyword argument) timeout can be given. This should be an integer representing the number of seconds before a send or receive should time out when the net dimm does not talk. This is normally determined automatically given a correct target keyword but you can also specify it manually.

crc() static method

Takes either a bytes or a FileBytes object and runs a CRC over the entire contents in the same way that the net dimm would CRC the same data. Use this to calculate what the expected CRC should be for a given chunk of data you might wish to upload to a net dimm or to compare against the CRC returned in an info() call to see if what you want to send is already running on the net dimm.

connection() context manager

Takes no arguments, and when run like with inst.connection(): will manage the connection to the net dimm for you. You do not need to use this function. However, if you are issuing many commands to the net dimm in a row, it is much faster to wrapp all of those function calls in a connection in order to remove the time it takes to connect and disconnect between every command.

info() method

Returns a NetDimmInfo containing information about the net dimm you have pointed at. The NetDimmInfo object has the following properties. The current_game_crc is an integer representing the CRC of the game currently running on the net dimm. Compare it to the output of the crc() static method for the same data. The current_game_size is an integer representing the size in bytes of the game currently running on the net dimm. The game_crc_status property is a CRCStatusEnum representing the current status of the CRC on the system, such as CRCStatusEnum.STATUS_VALID or CRCStatusEnum.STATUS_INVALID. This allows you to check whether the net dimm thinks the onboard CRC matches the onboard data. The memory_size property is an integer representing the number of megabytes of RAM installed in the net dimm. The available_game_memory represents the maximum size in bytes of a game that may be stored on the net dimm. The firmware_version property is a NetDimmVersionEnum representing the version of the net dimm firmware running. Note that when you call the info() method, the version property on your net dimm instance will be updated accordingly.

send() method

Send a game to the net dimm. Takes a data argument which can either be bytes or FileBytes and sends it to the net dimm. This also takes care of setting the net dimm information and setting the onbaord DES key. If you give the optional key argument, that key will be used to encrypt the game data as well as set the crypto key on the net dimm. By default you do not need to use this. If you give the optional boolean disable_crc_check argument then the net dimm will not CRC the data after you send it and will instead boot directly into it. When this mode is set, the game_crc_status returned from the info() call will have a value of CRCStatusEnum.STATUS_DISABLED. If you give it the optional progress_callback argument in the form of a function that takes two integer parameters and returns nothing, then this function will call that function periodically with the current send location and the send size in bytes to inform you of the send progress which can take awhile.

receive() method

Receive a previously sent game from the net dimm. Ensures that the game itself on the net dimm is valid and then downloads the entire contents before returning it as bytes. If the game could not be retrieved because it has an invalid CRC or there is no game installed, this returns None. Much like the send() method, this takes an optional progress_callback argument in the form of a function with two integer parameters and returning nothing. If this is provided, the callack will be called periodically with the current location and receive size of the game being downloaded.

send_chunk() method

Send a chunk of binary data to the net dimm, stored at an offset. Takes two parameters, the first being the integer offset from the beginning of the net dimm writeable memory to put the binary data, and the second being either bytes or FileBytes and sends the entire chunk to that location. Note that this is not to be used to upload game data as it does not attempt to calculate or update the CRC. Using this to change data within the CRC'd section of a valid sent game will cause it to become invalid on the next boot. If you send data to a running game, you can subsequently read that data using the cartridge read interface on running target.

receive_chunk() method

Receive a chunk of binary data from the net dimm. Takes two parameters, the first being an integer offset from the beginning of the net dimm writeable memory to get the binary data, and the second being an integer length in bytes of the amount of data to receive. Note that if you use the cartridge write interface on the running target to write data to the cart, it will be available to read using this function.

reboot() method

Reboot the net dimm after sending a game in order to boot the game. This can be issued at any time, but it makes most sense to do so after finishing an upload.

peek() method

Given an address as an integer and a type in the form of either PeekPokeTypeEnum.TYPE_BYTE, PeekPokeTypeEnum.TYPE_SHORT or PeekPokeTypeEnum.TYPE_LONG, attempts to read that size of data from that address from the target system running the net dimm. Returns the actual value or 0 if it could not be retrieved.

poke() method

Given an address as an integer, a type in the form of either PeekPokeTypeEnum.TYPE_BYTE, PeekPokeTypeEnum.TYPE_SHORT or PeekPokeTypeEnum.TYPE_LONG and a data value, attempts to write that size of data to that address on the target system running the net dimm.

Naomi Homebrew Messaging Protocol

The netdimm module provides a series of functions that are capable of talking to a Naomi homebrew program through a net dimm. Both low level packet-based and slightly higher-level message-based functions are provided for you depending on your needs. They correspond to the functions implemented in naomi/message/packet.h and naomi/message/message.h respectively. The packet-based interface provides the ability to read or write one packet at a time, read from or write to two scratch registers and read from a configuration register. The message-based interface provides the ability to send or receive optionally-compressed messages (binary data with a type) which can be up to 64kb in size.

The MAX_MESSAGE_LENGTH constant gives you the size that you should not exceed when sending messages, and the MAX_PACKET_LENGTH constant gives you the size you should not exceed when sending packets.

The Message class is available for you when sending and receiving messages. Its constructor takes a type argument which should be an integer in the range 0x0-0x7FFF and optionally a data argument containing up to MAX_MESSAGE_LENGTH bytes as the message payload. The packet type is available on instantiated Message classes using the id attribute, and optional data is available on the data attribute. Note that when a message contains no data, the data attribute will be Null.

The protocol is entirely host-driven. The Naomi program will not discard or attempt to send or receive a packet or message without the host driving it. This is because the Naomi has no way of requesting a net dimm send a packet, but the host has the ability to request peek and poke messages that are performed on the Naomi's main RAM. Thus, it is your responsibility to call either receive_packet or receive_message in an event loop in order to keep the Naomi ROM's buffers from filling.

send_packet

Takes an instantiated NetDimm class and a bytes object representing between 1 and 253 bytes of data to send to the Naomi program. Returns True if the packet was successfully sent or False otherwise.

receive_packet

Takes an instantiated NetDimm class and attempts to receive a single packet between 1 and 253 bytes long from the Naomi program. If successful, the byte data inside the packet will be returned. Otherwise, None is returned.

read_scratch1_register

Attempts to read the 32-bit scratch1 register (usable for anything you want). Returns the 32-bit value on success or None if the register could not be read.

read_scratch2_register

Attempts to read the 32-bit scratch2 register (usable for anything you want). Returns the 32-bit value on success or None if the register could not be read.

write_scratch1_register

Attempts to write an integer parameter to the 32-bit scratch1 register. There is no checking that this operation succeeded, though it generally does. If you wish to be sure, you can read back the contents.

write_scratch2_register

Attempts to write an integer parameter to the 32-bit scratch2 register. There is no checking that this operation succeeded, though it generally does. If you wish to be sure, you can read back the contents.

send_message

Takes an instantiated NetDimm class and an instance of Message and attempts to send that message to a Naomi program. Raises MessageException on failure to send the message. This can happen if the Naomi program isn't running the message protocol or if the program has crashed.

receive_message

Takes an instantiated NetDimm class and attempts to receive a message from a Naomi program. Raises MessageException on critical failures, such as malformed packets or if the Naomi program isn't running the message protocol. Returns an instance of Message representing the received message on success, and returns None if there was no message ready to receive.

Note that correctly configured Naomi homebrew programs that have installed the stdio redirect hooks to send stdout and stderr to a communicating host will send message of type MESSAGE_HOST_STDOUT and MESSAGE_HOST_STDERR when the respective streams have data. These are flushed when a newline is received and contain that newline in the data. To correctly display these, it is recommended to decode them as utf-8 data and display them verbatum.