NetHack Porting Guidelines v 3.6 1999-11-29

1.0 Introduction

This document goes through the steps required to port NetHack to a

new machine. The basic steps in porting the program are:

1. Get the code onto your machine. The parts of the current

directory setup you definitely need include src (NetHack code

shared by all systems), include (include files), util (code

for utility programs), and dat (various data files). The

documentation in doc is strongly recommended. You already

have the files in the top directory since you're reading this

one. :-)

A full list of the distribution files and their associated

OSes may be found in the top-level file "Files".

If your machine uses an OS already supported, you need the sys

subdirectory for that OS and possibly sys/share. Otherwise,

get the closest match (say sys/msdos for single-tasking OSes

and sys/unix for multi-user OSes, along with sys/share, if

nothing else comes to mind). You may want others for

comparison.

If your machine uses a windowing system already supported,

you need the win subdirectory for that system (or the

appropriate sys subdirectory if the windowing system was

previously considered restricted to one OS) and possibly

win/share.

2. Modify the appropriate include files to customize NetHack to

your system. You may need to add a new OS-specific "*conf.h"

file (see unixconf.h, pcconf.h, tosconf.h, etc. as examples).

3. If your machine uses a new OS instead of a variant of existing

OSes, add a new sys subdirectory. Add, if required, a OS-

specific copy of "main.c", "tty.c" and "unix.c". Possibly

add an OS-specific library (see "msdos.c" and "tos.c" as

examples) to provide functions NetHack wants and your OS lacks.

4. If your machine uses a new windowing system, follow doc/window.doc

carefully. Put files implementing these routines in a win or

sys subdirectory as appropriate.

5. If your compilation environment isn't close to one already

supported, try starting from the UNIX makefiles. Modify the

top level makefile and the src makefile as required. Then run

an initial compile. You are bound to get some errors. You

should be able to fix them in a fairly simple fashion. If

things seem to be getting too complex, take a step back, and

possibly send us some mail. We might be able to help.

6. Mail all of your fixes to us in a contextual form so that we can

easily integrate them into the code.

One general rule of thumb exists. Always add code. Don't delete

somebody else's code for yours -- it won't work on their machine if you do.

Always add your OS specific code inside #ifdef / #else / #endif constructs

so that it will be able to be folded back into the original code easily.

2.0 Include Files

2.1 config.h

The file "config.h" is a master configuration file that determines

the basic features of the game, as well as many of the security options.

It is intended that end users configure the game by editing "config.h" and

an appropriate "*conf.h" file, so any #defines for individual preferences

should be added to those files. OS-specific #defines that are not intended

to be changed should also go in "*conf.h"; try to find the most appropriate

place for other #defines.

The following sections may require modification:

- Section 1: OS and window system selection.

You may have to put a #define for your OS here.

If your OS is yet another UNIX variant, put the

#define in unixconf.h instead.

An unfortunately large amount of stuff shares

this section because the #definitions have to

be seen before *conf.h is reached. Don't add

to this unless necessary.

- Section 2: Global parameters and filenames.

These will have to be customized to your system.

- Section 3: Type definitions and other compiler behavior.

These will have to be matched to your compiler.

2.2 global.h

This file defines things specific to NetHack that should not

require modification by an end user. For a new port, you may have to add

automatic inclusion of another auxiliary config file (*conf.h) which you

wrote for your system.

2.3 extern.h

If you create any new source modules or new functions in old modules,

you must enter the names of the new external references (the functions defined

there for external use) in this file.

2.4 system.h

This file contains references for all hooks into the OS (via the

standard "C" libraries). Depending on what your standard library looks like,

you may have to put new entries into this file.

3.0 Source files

The first step in getting the game up is to get the "makedefs"

program running. This program is used to create configuration-specific

files for the game.

Once "makedefs" has been built, the rest of the game can be compiled.

You may have to create an OS-specific module to handle things you want to

use, like a mouse or a ram-disk.

The utility compilers "dgn_comp" and "lev_comp" may be a better

place to start. They also require "makedefs" but are independent of

"nethack". They are usually the last programs made, but since they are

much smaller they may be more tractable when first arguing with the include

files. These programs create binary data files that "nethack" uses to

guide its dungeon creation.

3.1 Makefiles

This distribution provides makefiles for several kinds of systems.

There are joint makefiles for the various varieties of UNIX, makefiles for

MSDOS, a makefile for NT, and so on. You may have to create a new

makefile for your specific machine. You may even have to translate some

makefiles into a form more congenial to your system. If possible, however,

add to one of those provided.

3.2 termcap.c

If your system wants to use tty windowing and it doesn't run off

of a termcap or terminfo database, you may have to put the appropriate

terminal control strings into termcap.c. This has already been done for

MSDOS, and these mods can be used as an example. You can also consider

using the termcap code from sys/share/tclib.c or sys/share/termcap.uu,

especially if your system supports multiple kinds of terminals.

3.3 main.c

You may need to create a new "main.c" module. If you do, call it

[OS]main.c where the [OS] is replaced with the name of the OS you are porting

to. This file contains the mainline module, which reads options from the

command line (or wherever) and processes them. It also contains various

functions associated with game startup.

3.4 tty.c

You may need to create a new "tty.c" module. If you do, call it

[OS]tty.c where the [OS] is replaced with the name of the OS you are porting

to. This file contains the routines that configure the terminal/console

for raw I/O, etc.

3.5 unix.c

You may need to create a new "unix.c" module. If you do, call it

[OS]unix.c where the [OS] is replaced with the name of the OS you are porting

to. This file contains some OS dependencies concerning time and filename

creation.

An object of the NetHack development project is to get the game

working on as many different types of hardware and under as many different

operating systems as is practical. Any assistance will be appreciated.