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IP creator (makeip)

IP creator (makeip) is an utility used for generating homebrew Sega Dreamcast bootstrap files, also known as IP which stands for Initial Program. This file is often named IP.BIN. It's a critical component for any Dreamcast discs.

IP.BIN file is used for making selfboot (MIL-CD) discs for Sega Dreamcast softwares. When the file is inserted in the bootsector of a disc, the bootstrap program (IP.BIN) will execute the main program stored on the file system which is often named 1ST_READ.BIN. Please note, the IP.BIN file is not needed on the file system as it's inserted in the bootsector.

IP creator will generates a custom IP.BIN file designed for homebrew programs. It uses minimal copyrighted code, i.e. the minimum code that can't be removed/altered in any way.

All IP.BIN files contains custom data fields used to describe some properties of the software present on the disc. IP creator will allow you to edit these fields. It also supports the insertion of custom images in the boot screen. These kind of images are called MR images or MR logos and are often stored in files with the .mr extension. You'll be able to convert a PNG image into the MR format on-the-fly with IP creator.

Below you'll find an example of the ADK/Napalm MR image shown in the boot screen (this MR logo was extracted from the dcload bootstrap):

Example

Building

This program is a standard C program which may be compiled with GNU Make. It requires libpng-dev installed. Learn more about libpng here.

  1. Edit the Makefile and check if everything is OK for you (e.g. libpng directories);
  2. Enter make (gmake on BSD systems).

Usage

To use this tool, several modes are available:

  1. Using a IP template file (ip.txt);
  2. Using command-line arguments.

Available options are (displayed with the -h switch):

-f                 Force overwrite output file if already exist
-h                 Print usage information (you're looking at it)
-l <infilename>    Load/insert an image into bootstrap (MR; PNG)
-t <tmplfilename>  Use an external IP.TMPL file (override default)
-u                 Print field usage information
-s <outfilename>   Save image from <infilename> to MR format (see '-l')
-v                 Enable verbose mode

To learn more about MR images, please read below. You may use either a raw MR image or a PNG image that will be converted on-the-fly.

Using a IP template file

This mode is the historical way to populate the fields of the IP.BIN file.

Create a text file called ip.txt and write this content on it:

Device Info   : CD-ROM1/1
Area Symbols  : JUE
Peripherals   : E000F10
Product No    : T0000
Version       : V1.000
Release Date  : 20000627
Boot Filename : 1ST_READ.BIN
SW Maker Name : YOUR NAME HERE
Game Title    : TITLE OF THE SOFTWARE

Then run the following command:

makeip ip.txt IP.BIN

This will generate the IP.BIN with the above values.

You don't have to fill all the fields, removing them from the ip.txt will use the default. So a minimal ip.txt file may be like:

Product No    : T0000
Version       : V1.000
SW Maker Name : YOUR NAME HERE
Game Title    : TITLE OF THE SOFTWARE

Note: In the original ip.txt files, you may have the fields Hardware ID and Maker ID declared. They can't be altered so it isn't necessary anymore to pass them. Plus, the Device Info field may contains a fake CRC like 0000 (see below in the Device Info field sub-section for more info), this isn't necessary now but it will still work if present.

Using command-line arguments

If you want you may pass directly the field information by using the proper switch. To print this list, use the -u switch instead of -h.

-a <areasymbols>    Area sym (J)apan, (U)SA, (E)urope (default: JUE)
-b <bootfilename>   Boot filename (default: 1ST_READ.BIN)
-c <companyname>    Company name / SW maker name (default: KallistiOS)
-d <releasedate>    Release date (format: YYYYMMDD, default: <today>)
-e <version>        Product version (default: V1.000)
-g <gametitle>      Title of the software (default: GAMETITLE)
-i <deviceinfo>     Device info (format: CD-ROMx/y, default: CD-ROM1/1)
-n <productno>      Product number (default: T-00000)
-p <peripherals>    Peripherals (default: E000F10)

MR Images

MR Image is a special image format that can be inserted in the boostrap. This kind of image are often saved as iplogo.mr or equivalent.

With IP creator you will be able to:

  • Insert a custom image in the generated bootstrap. It can be either raw MR format or PNG format;
  • Convert an input file (i.e. a PNG file) into the MR format and save the result on the disk for later use.

Inserting an image into bootstrap

Just pass the -l switch to the command-line:

makeip -l iplogo.mr -v IP.BIN

You may pass a PNG file too:

makeip -l iplogo.png -v IP.BIN

In that case, the PNG file will be converted on-the-fly in the MR format before inserting in the bootstrap.

About MR Image constraints

To be used in the generated IP.BIN file, the MR image must be:

  1. 320 * 90 or less;
  2. Less than 128 colors;
  3. Less than 8192 Bytes.

The transparent color is #c0c0c0, or 192, 192, 192 in RGB.

Converting a PNG Image into a MR Image

If you just want to convert a PNG Image to a MR Image but not generating the bootstrap, you may use IP creator like:

makeip -l iplogo.png -s iplogo.mr -v

This will try to convert the iplogo.png to the iplogo.mr file.

Of course, you may generate a bootstrap and write the converted image on the disk at the same time:

makeip -l iplogo.png -s iplogo.mr -v IP.BIN

Information about some specific fields

Some fields used in the bootstrap need to be detailed, as they are have constraints:

  • Area Symbols
  • Device Information
  • Peripherals
  • Release Date
  • (Product) Version

Area Symbols

The Area Symbols field consists of 8 characters, which are either space or a specific letter. Each of these represent a geographical region in which the disc is designed to work. So far, only the first 3 are assigned, the 5 others were never been used so they are just left blank.

Supported area are Japan (and the rest of East Asia), USA + Canada, and Europe.

If the character for a particular region is a space, the disc will not be playable in that region. If it contains the correct region character, it will be.

The region characters used are J, U, and E, respectively. So a disc only playable in Europe would have an Area Symbols string of " E ". This operation is made by IP creator.

To summarize, if you want your program region-free, you just have to assign JUE to the Area Symbols field. This is the case by default.

Device Information

The Device Information field begins with a 4 digit hexadecimal number, which is a CRC on the Product Number and Product Version fields (16 bytes). Then comes the string " CD-ROM", and finally an indication of how many discs this software uses, and which of these discs that this is. This is indicated by 2 positive numbers separated with a slash. So if this is the second disc of three, the Device Information field might be something like "8B40 CD-ROM2/3 ".

Please note, commercial IP.BIN files (which aren't produced by IP creator) supports the " GD-ROM" type. Also, the CRC value doesn't need to be provided as it's computed automatically by the IP creator program.

In clear, you just have to pass CD-ROMx/y to that field, where x is the disc number and y the total discs in the set. The default value is CD-ROM1/1.

Peripherals

The Peripherals field is a 28 bit long bitfield represented by a 7 digit hexadecimal number. The meaning of the individual bits in each digit is given below:

<A><-------B------> <C->
0000 0000 0000 0000 0000 0000 0000
^^^^ ^^^^ ^^^^ ^^^^ ^^^^    ^    ^
|||| |||| |||| |||| ||||    |    |
|||| |||| |||| |||| ||||    |    +----- Uses Windows CE
|||| |||| |||| |||| ||||    |
|||| |||| |||| |||| ||||    +-----  VGA box support
|||| |||| |||| |||| ||||
|||| |||| |||| |||| |||+----- Other expansions
|||| |||| |||| |||| ||+----- Puru Puru pack
|||| |||| |||| |||| |+----- Mike device
|||| |||| |||| |||| +----- Memory card
|||| |||| |||| |||+------ Start + A + B + Directions
|||| |||| |||| ||+------ C button
|||| |||| |||| |+------ D button
|||| |||| |||| +------ X button
|||| |||| |||+------- Y button
|||| |||| ||+------- Z button
|||| |||| |+------- Expanded direction buttons
|||| |||| +------- Analog R trigger
|||| |||+-------- Analog L trigger
|||| ||+-------- Analog horizontal controller
|||| |+-------- Analog vertical controller
|||| +-------- Expanded analog horizontal
|||+--------- Expanded analog vertical
||+--------- Gun
|+--------- Keyboard
+--------- Mouse

The group of bits indicated by B above indicate the discs minimum controller requirements. So if the Z button bit is set, the software can not be used with a controller that doesn't have a Z button. The A group indicates which optional peripherals the disc supports. The C group indicates which kinds of expansion units that the disc supports. The VGA box support bit indicates that the disc can be run in VGA mode. The WinCE bit speaks for itself and shouldn't be used for any homebrew program, so you have to leave this field to 0.

Release Date

The Release Date field is in the YYYYMMDD format. By default, it's initialized with today.

(Product) Version

The Version field is the Vx.yyy format, where x is the major number and yyy the minor number. Default is V1.000.

GIMP MR Image Plug-In

GIMP is a cross-platform image editor available for GNU/Linux, macOS and Windows. The provided gimp/file-mr.py file is a GIMP plug-in used for encode/decode MR images.

So by using this plug-in, you can load and save .mr files directly in GIMP. As this plugin uses Python-Fu, you should have Python extensions enabled in GIMP. Read more here.

To install the GIMP Plug-In:

  1. Make the plug-in executable: chmod +x file-mr.py or equivalent.
  2. Place the plug-in in the plugins directory. This directory is different depending on what operating system you use. To find out go to GIMP > Preferences > Folders (Expand option) > Plugins (see below an example under Windows, but this applies to others OS).
  3. That's it!

GIMP Plug-In Directory

Acknowledgments

License

This project is licensed under the BSD 2-clause "Simplified" License - see the LICENSE file for details.