parasyte / n64rd

Nintendo 64 Remote Debugger

n64rd

Nintendo 64 Remote Debugger

Building

Requirements

• Python - For SCons
• SCons - Build system

To build a release version

$ scons

To build a debug version

$ scons debug=1

To clean

$ scons -c

Running

$ n64rd -h
n64rd v0.2
By Parasyte ([e-mail])
Website: http://www.kodewerx.org/
Build date: Aug 10 2014, 12:31:45

Usage: n64rd [options]
Options:
  -h            Print usage and quit.
  -p <port>     Specify port number (default 0x378).
                Linux systems with PPDev can use a path.
                e.g. "/dev/parport0"
  -v            Detect GS firmware version.
  -a <address>  Specify address (default 0x80000000).
  -l <length>   Specify length (default 0x00400000).
  -d[file]      Dump memory 32-bits at a time;
                Copy <length> bytes from memory <address> (to [file]).
  -r[file]      Read memory;
                Copy <length> bytes from memory <address> (to [file]).
  -w <file>     Write memory;
                Copy from <file> to memory <address>.
  -u <file>     Upgrade ROM with given file.

Points of Interest

Differences between -r and -d

The main differences between the -r and -d options are:

• -r reads one byte at a time. -d reads one word at a time. This makes -d suitable for reading from ROM space, while -r is not.
• -r is restricted to reading valid addresses only. The "invalid" address ranges are listed below. -d is completely unrestricted; they didn't even try!
• -r keeps the game paused when it is finished. -d unpauses immediately when finished.
• -r can only be used in-game. -d can be used in the menu or in-game.

Invalid read ranges

  0x80780000 - 0x807FFFFF
  0xBDFFFFFF - 0xFFFFFFFF

Note that the mirrored address range 0xA0780000 - 0xA07FFFFF is VALID, so it can be read easily. It also does not take into account the length of the data being read. Therefore it's possible to read these invalid ranges by starting at a lower address and reading more data. Reading 0x80000000 - 0x807FFFFF is perfectly acceptable. (Something, something horrible programming.)

If it sounds like the -d option is more useful, you're probably right. The only exception is when you want to read memory but leave the game paused. And that is easy to patch into the -d options, anyway. (Patches are forthcoming!)

Dumping N64 ROMs

Dump the cartridge ROM with:

$ ./n64rd -dgame.n64 -a 0xB0000000 -l 0x0E000000

You will then have game.n64 file that is 224MB in size. This should be large enough for ANY N64 ROM. But it will be way too much for the majority of games. The ROM data will repeat in well-defined intervals. You can adjust -l to save a lot of time, if you know the exact ROM size.

Dumping the GS ROM

Dump the GS ROM with:

$ ./n64rd -dgs.n64 -a 0xBEC00000 -l 0x00040000