NFMEditor.exe — .NFM Multiplayer/Server Config Editor (deep-dive)

Reference record; not an oracle target. See the editor-tools overview.

1. Binary facts

File	reference\NFMEditor.exe
Size	471,040 B (0x73000)
SHA-256	173db0b5f7c7000febf86e7c21519c24f8e11cdab41730d049a1fd22aaf3aa21
Toolchain	MSVC6, Linker 6.0, TimeDateStamp 2003-02-15 19:57:40Z
Machine / Subsystem	x86 (0x014C) / GUI (2)
ImageBase	0x00400000
Sections	.text RVA 0x1000 VSize 0x5CFDE · .rdata RVA 0x5E000 · .data RVA 0x6E000 VSize 0x775B0 · .rsrc RVA 0xE6000
Entry	0x0045BE5F
Imports	MFC42 (138), MSVCRT (66), KERNEL32 (84), USER32 (63), GDI32 (12), ADVAPI32 (12), ole32 (3), MSACM32 (7), VERSION (3), WINMM (5)
Rich header	XOR key 0x72BAA77B, DanS @ 0x80 (Linker 6.00 SP6 + C7 toolset)
Functions	1,129 (Ghidra)

MFC42 is imported dynamically (no static MFC in .text), unlike the game EXE. The tool must run from the game install root — it loads GameOS resources and Language.dll from assets\binaries\, and reads/writes resource\Missions\*.nfm / resource\UserMissions\*.nfm.

2. Purpose

NFMEditor edits the .nfm "network/multiplayer mission" files that define a map's multiplayer rulesets and scenarios (see docs/editor_tools/README.md for the file's place in the game data set). Each map in resource\Missions\ / resource\UserMissions\ has one .nfm describing:

• [info] — author / blurb / link / long display name,
• [ruleset] — the list of game-type rules that may be launched on the map, each rule = a type=$(<GameType>) macro entry + optional team / alignment,
• [scenarios] — named scenario blocks (Name={ ... }), each with a [server] sub-section of per-scenario settings (game type, teams, kill/respawn limits, night/weather/radar, tonnage/C-Bill caps, game length, script name) and optional team_N/bot_N sub-blocks for per-team and per-bot constraints.

It also edits the Server Cycle List (servercycle.txt, via -cycle <file>): a rotation of map=Name.nfm::ScenarioName entries the game server walks to cycle maps.

The .nfm/servercycle.txt text format is GameOS's generic "info file" parser (a C-preprocessor-like key/value grammar) — see §4.

3. Layout — .text regions

Range	Size	Content
0x401000–0x4072xx	~25 KB	Editor app code (dialog, .nfm load/save, cycle list)
0x408xxx–0x44Exxx	~290 KB	Bundled GameOS framework (same engine code as MW4Mercs.exe)
0x44F000–0x458xxx	~40 KB	The "info file" parser/serializer library (pure, reusable)
0x459000–0x45BE00	~12 KB	MFC glue + GameOS helpers + Ordinal thunks (0x45BBxx–0x45BExx)
0x45EA00+	—	Class vtables in .rdata (PTR_LAB_0045ea00 = app vtable)

The Ghidra inventory names most MFC imports by Ordinal_XXXX (jmp-thunk table at 0x45BB80+); e.g. Ordinal_2864 = the frame/app singleton accessor, Ordinal_6907 = list-control "set item text", Ordinal_3996 = list-control "insert column", Ordinal_3302 = list-control "get item text", Ordinal_2642 = MFC "invalidate" family, Ordinal_6199 = string lowercase, Ordinal_3998 = list "insert item".

4. The "info file" format (GameOS generic key/value text)

.nfm, servercycle.txt, Content\GameTypes.h (the include), and the resource\missions\*.txt scenario-text files are all read by one parser family. Ground truth: the shipped files (see §5/§6) plus the parser below.

4.1 Grammar

Read line by line (\r\n or \n), 512-byte line buffer, 0x200 max per line:

• Comments: // to end of line; /* ... */ block (multi-line; error "There is a missing */ in %s" on EOF). /* */ is stripped inline.
• Line-continuation/escape: a line beginning with @ has the @ removed (used to force literal interpretation / preserve case on an otherwise lowercased line). Lines that do not start with @ are lowercased (_strlwr) unless !preservecase=true is in effect.
• Whitespace: leading/trailing spaces and tabs on a line are trimmed; keys are right-trimmed.
• [SectionName] — section header (name trimmed). A ]-less header is rejected (incomplete).
• key=value — key/value pair in the current section. Keys may repeat (all occurrences are kept; lookups return the first, case-insensitive).
• Name={ — a block: Name becomes a key whose value is a nested section list. Contents are parsed recursively until a lone } line closes the block. Serializer re-emits Name={ + nested sections + }. A missing } at EOF is an error ("There is a missing } in %s").
• !directive — control directives (see 4.2).
• #define name value — C-preprocessor-style macro definition (this is how Content\GameTypes.h works).
• $(name) — macro reference, expanded recursively at parse time (the $(StockBattle) in the shipped files becomes 0). Any key=value line whose value contains $( is macro-expanded. Recursive expansion is cycle-guarded.
• Bare lines — a line with no = and no [ creates a key with an empty value (harmless).

Macros are resolved from the macro table (name → value). #define lines add to it; unknown $(...) references resolve to the empty string.

4.2 Directives (!...)

Directive	Effect
!include=<path>	Parse <path> as another info file into the same tree; relative paths resolve against the including file's directory. Quoted paths allowed. Include files are deduped via an include cache (a file is parsed once).
!concatenate=true\|yes\|1	Toggle concatenation mode (parser flag).
!preservecase=true\|yes\|1	Toggle case preservation (default: keys/values lowercased). The shipped .nfm files set !preservecase=true.
!<name>=<value>	Define a custom macro/directive name → value.

4.3 In-memory tree

• Root/tree object: +0x00 first-section, +0x05 concatenate flag, +0x06 preservecase flag, +0x0c include list, +0x44 sorted section list (doubly linked, head at +0x44), +0x48 count, +0x4c parser context. Created by FUN_00451390, freed by FUN_00451510.
• Section node (0x20 B, FUN_004524b0): +0x00 vtable, +0x04 parent, +0x14 name, +0x18 key list. Sections are kept sorted by name.
• Key node (0x1C B, FUN_00453c40): +0x00 vtable, +0x04 owning section, +0x14 key name, +0x18 value string (or block). Every parse creates a new node (duplicate keys retained); FUN_00453b50 returns the first case-insensitive match.
• Block contents are a nested section list hung off the block key (assembled by FUN_00454f20, serialized by FUN_00451b40).

4.4 Parser/serializer function map (the reusable library)

VA	Size	Role
0x00451390	171	Parse-file entry: open + parse + missing/empty check ("%s is missing or empty!")
0x00450960	295	File open/read wrapper (mode 0 read / 1 write)
0x00450900 / 0x00450940	60/23	File wrapper ctor / close
0x004515c0	107	Parse setup → calls parse loop
0x00451630	1293	Parse loop (line reader, comment/@/trim handling)
0x00451c40	653	Line handler: [section], key=value, key={ block recursion
0x00451ed0	1098	! directive handler (include/concatenate/preservecase/custom)
0x00452320	139	#define handler
0x00451270	285	$(macro) resolver (recursive, cycle-guarded)
0x004510e0	397	Macro-table define
0x004523b0 / 0x00452490	147/31	Section lookup / find-or-create (block mode)
0x004524b0	292	Create/insert section node
0x00453c40	116	Append key node (duplicates allowed)
0x00453b50	62	Key lookup (first match, case-insensitive)
0x00453d30 / 0x00453df0	80/83	Read string / int value (required flag → "%s: [%s]%s is a required entry!")
0x00453dc0 / 0x00453e80	40/25	Set string / int value
0x004544d0 / 0x00454d80	83/416	Read sub-tree (block contents)
0x00454f20	277	Block attach/serialize (Name={ … })
0x00451b90	84	Serialize entry: write tree to its file
0x00451b40	67	Recursive section serializer
0x00453a80	205	Section serializer ([name]\r\n, blank line after)
0x00454610	161	Key serializer (key / key=value\r\n)
0x004578a0	174	Include-file registration
0x00450310 / 0x004505b0	558/54	FindFirstFile/FindNextFile-style directory scan wrapper

Output is written with \r\n line endings; a blank line separates sections.

5. The .nfm format spec

Ground truth = the 21 shipped files (resource\MISSIONS\*.nfm) + the editor's reader (FUN_00404f00) + writer (FUN_004060b0).

5.1 Top-level layout

!include=Content\GameTypes.h
!preservecase=true

[info]
author=...
info=...            (e.g. "Standard Mission")
link=...            (e.g. www.microsoft.com/games/mechwarrior4)
longname=...        (display name, e.g. "Alpine")

[ruleset]
type=$(StockBattle)         <- one line per allowed rule
type=$(StockTeamBattle)
team=8                      <- optional per-rule team count
alignment=6                 <- optional per-rule alignment

[scenarios]
ScenarioName={
[server]
    ruleset=$(StockDestruction)
    name=...                (optional)
    teamAllowed=0|1
    teamcount=<0..8>
    scenariotext=resource\missions\<file>.txt   (optional)
    ... more optional keys (5.3) ...
    team_0={ teamdata{ ... } }   (optional, see 5.4)
    bot_0={ botdata{ ... } }     (optional, see 5.5)
}

The shipped files use a tab to indent the [server] block's keys (the parser trims whitespace, so indentation is cosmetic).

5.2 Game-type macros (Content\GameTypes.h)

!include=Content\GameTypes.h is a preprocessor file, not a tree section: #define lines feed the macro table. Values:

Macro	Value		Macro	Value
$(StockBattle)	0		$(CustomBattle)	6
$(StockTeamBattle)	1		$(CustomTeamBattle)	7
$(StockDestruction)	2		$(CustomDestruction)	8
$(StockTeamDestruction)	3		$(CustomTeamDestruction)	9
$(StockMissionPlay)	4		$(CustomMissionPlay)	10
$(StockCampaign)	5		$(CustomCampaign)	11
			$(CustomUndefined)	12
			$(SinglePlayer)	13

GameTypeCount = CustomUndefined + 1 = 13 (the editor's per-type arrays are sized 13; index 13/SinglePlayer is a separate flag). Note the editor's display strings are the $(...) forms — the shipped defianceholds.nfm uses ruleset=$(StockMissionPlay) inside [server], which resolves to 4.

5.3 [server] keys, types and validation ranges (from the editor)

Key	Type	Range / values	Written if
ruleset	int	0..12 (game-type index)	always
name	string	—	always (map name)
teamAllowed	int	0 or 1	always
teamcount	int	1..8 (if teamAllowed); else forced 0/0	always
scenariotext	string	path (e.g. resource\missions\des.txt)	non-empty
killLimit	int	0 or 1	non-empty
killLimitNumber	int	1..99 (default 10)	killLimit==1
respawnLimit	int	0 or 1	non-empty
respawnWaveNumber	int	1..9 (default 1)	respawnLimit==1
isNight	int	0 or 1	non-empty
weather	int	0 or 1	non-empty
radarmode	int	0..2	always (0 default)
onlyStockMech	int	0 or 1	non-empty
maximumtonnage	int	25..100	non-empty
maximumCBills	int	2,000,000..34,999,999	non-empty
gameLength	int	1..120 (minutes)	non-empty
scriptName	string	custom script name	non-empty

(The [server] keys are case-insensitive — the shipped files mix teamAllowed and teamcount casing; the writer emits teamcount lower-case.)

5.4 team_N block (teamdata sub-key)

Written per team index N while teamAllowed==1:

team_0={
teamdata{
maximumTonnage=25..100
minimumTonnage=25..100
maximumTotalTonnage=100..1600
maximumCBills=2000000..35000000
maximumTotalCBills=2000000..500000000
maxPlayersOnTeam=1..16
skin=<single char '0'-'9' or 'a'-'z'>
alignment=0..7
}
}

Each field is emitted only when set (a non-default value). Constraint checked: max ≥ min (else both invalidated).

5.5 bot_N block (botdata sub-key)

bot_0={
botdata{
botCount=1..14
team=<1..teamcount>        (only meaningful when teamAllowed==1)
maximumTonnage=25..100
minimumTonnage=25..100
maximumLevel=0..9
minimumLevel=0..9
}
}

5.6 [ruleset] details

Repeated type=$(...) entries are the mechanism for a multi-rule map: each type= line is one allowed game type. Per-rule optional keys follow their type line: team=<1..8> (team count) and alignment=<0..6>. The stock alpine.nfm declares two rule groups (destruction + team-destruction, and battle + team-battle). The editor's per-type arrays (+0x4e8 flags, +0x554 team count, +0x588 alignment) mirror these. If the single-player flag is set, the writer emits a type=$(SinglePlayer) line in [ruleset].

5.7 Round-trip behavior

• Load (FUN_00404f00): parse <dir>\<map>.nfm, populate ruleset flags + scenario list + per-scenario server/team/bot rows; out-of-range values are clamped or dropped (defaults shown above).
• Save (FUN_004060b0): rebuild the tree from the UI and serialize. Only non-default fields are written (except the always-written keys). The output is normalized: !include / !preservecase first, then [info], [ruleset], [scenarios]. The original file's own formatting/comment/order is not preserved (parse→modify→re-serialize).

6. The Server Cycle List (servercycle.txt)

• CLI: NFMEditor.exe -cycle <file> (also -cycle <file> with a trailing space). FUN_00401210 validates the argument ("INVALID PARAMETER - No parameter", "INVALID PARAMETER - No space after"); default file is servercycle.txt (FUN_004012c0, InitInstance).
• Format (ground truth: the shipped ServerCycle.txt):

[cycle]
map=Shoreline.nfm::Shoreline3
map=Alpine.nfm::Alpine4
...

Each entry: map=<mapfile>::<ScenarioName> (scenario = the [scenarios] block name in the map's .nfm). The editor list shows two columns (map name, scenario/game-type) joined with ::. - Save: FUN_00402720 (invoked from the OnClose handler 0x00402E80, which prompts "Do you want to save the Server Cycle List?"). On exit with an empty list: "The current Server Cycle List is empty. ... will stay at its last saved state.". Success message: "Server Cycle List Saved.". - Row population from an .nfm is FUN_004023a0 (reads a scenario's [server] ruleset/teamAllowed/teamcount into one list row).

7. Editor UI structure (main dialog object offsets)

The main window object (thiscall param_1 throughout the handlers) layout:

Offset	Control / field
+0x20 / +0x24	parent handles (frame access via Ordinal_2864)
+0x2c0	Server-cycle list control (columns: map, scenario)
+0x340	Missions/UserMissions folder combo (0=resource\Missions\, 1=resource\UserMissions\)
+0x380	Map listbox (populated from *.nfm by FUN_00401e00)
+0x3c0	Rules list (18 columns, see below)
+0x180	Bot list (7 columns)
+0x400	longname edit
+0x480	info edit
+0x3a8	"has current file" flag
+0x4dc	app icon (ID 0x80)
+0x4e8	13 × game-type enabled flag (one per GameTypeCount)
+0x51c	13 × per-type custom script-name list head
+0x554	13 × per-type team count (default 8)
+0x588	13 × per-type alignment (default 6)
+0x550	SinglePlayer flag (game-type index 13)

List columns (from FUN_00404b60):

• Rules (+0x3c0, 18): Rule Name, Rule Set, Scenario Name, Team Allowed, Team Count, Scenario Text File Name, Kill Limit Allowed, Kill Limit Count, # of Waves Allowed, # of Waves Count, Night, Weather, Radar Mode, Stock 'Mechs Only, Max Tonnage, Max C-Bills, Game Length, Custom Script Name.
• Teams (+0x380, 9): Team #, Max Tonnage, Min Tonnage, Max Total Tonnage, Max C-Bills, Max Total C-Bills, Max # of Players, Skin, Alignment.
• Bots (+0x180, 7): Rule #, # of Bots, Team #, Max Tonnage, Min Tonnage, Max AI Level, Min AI Level.

Handlers: FUN_00404b60 = New/Open (sets columns, default file new.nfm or loads current via FUN_00404f00); FUN_00404f00 = load; FUN_004060b0 = save; FUN_00406ee0/00406fe0 = populate team/bot lists; FUN_00406eb0/00406fb0 = per-scenario team/bot data accessors; FUN_00407120/00407160 = ruleset helpers; 0x00402E80 = OnClose (cycle-list save prompt).

8. Bundled GameOS framework (0x408xxx–0x44Exxx)

The tool links a large slice of the GameOS engine (the same framework the game EXE uses), which is why it must run from the game root:

• DirectSound init/caps dump (FUN_0041a0b0, 16.7 KB — the big SECONDARYMONO/SECONDARYSTEREO/MaxHwMixing*/FreeHw3D* report builder over the DAT_00470810 caps table), GameOS memory manager (heap tags DAT_004e4a38/004e4b48, "GameOS_Memory*", "GameOS Parent Heap"), file/mapped-file I/O (CreateFileMappingA, UnmapViewOfFile),
• Direct3D/DirectDraw/DirectInput/DirectPlay wrapper error tables (D3DERR_, DDERR_, DIERR_, DPERR_), texture codecs (BMP/TGA/JPG loading, mipmap rules — the "Only power of 2..." diagnostics), registry helpers (\Config\Platform, Config Manager\Enum), AGP miniport detection,
• Language.dll / blade.dll / gundll.dll / dbghelp.dll / dsetup.dll / ijl10.dll loader strings, GameOS.vxd, MAPI (MAPISendMail), a SQL connection string (DRIVER={SQL Server};...), VideoCard.txt dump.

This is the same subsystem family as the game EXE's bundled engine code; the .nfm reader/writer and the info-file library (§4) are the parts unique to this tool's workflow (the game EXE reads .nfm with its own copy of the same info parser — see src\mw4mercs).

9. Notable strings (VA → value)

0x46E108 servercycle.txt · 0x46E61C/0x46E634 resource\Missions\*.nfm / resource\UserMissions\*.nfm · 0x46EBC4 new.nfm · 0x46E1D4 NFM File · 0x46EEA0 Content\GameTypes.h · 0x46EEB4 !include · 0x46EEC8 !preservecase · 0x46EE74/0x46EE88 resource\Missions\ / resource\UserMissions\ · 0x46E738 cycle · 0x46E744 map · 0x46E740 :: · 0x46E764 Do you want to save the Server Cycle List? · 0x46E7B4 The current Server Cycle List is empty. ... · 0x46E74F Server Cycle List Saved. · 0x46ED4C Not enough memory to view the current NFO file. (sic)

Field strings ([server]/blocks): ruleset 0x46EC24/0x46EC68 · scenarios 0x46EC54 · server 0x46EC60 · teamAllowed 0x46EC78 · teamCount 0x46EC84 · scenarioText 0x46EC90 · killLimit 0x46ECA0 · killLimitNumber 0x46ECAC · respawnLimit 0x46ECBC · respawnWaveNumber 0x46ECCC · isNight 0x46ECE0 · weather 0x46ECE8 · radarMode 0x46ECF0 · onlyStockMech 0x46ECFC · maximumTonnage 0x46ED0C · maximumCBills 0x46ED1C · gameLength 0x46ED2C · scriptName 0x46ED38 · team_%d 0x46ED7C · teamdata 0x46ED84 · maximumTotalTonnage 0x46EDB0 · maximumTotalCBills 0x46EDD4 · maxPlayersOnTeam 0x46EDE8 · skin 0x46EDFC · alignment 0x46EE04 · bot_%d 0x46EE10 · botdata 0x46EE18 · botCount 0x46EE20 · team 0x46EE2C · maximumLevel 0x46EE54 · minimumLevel 0x46EE64 · info 0x46EED8 · author 0x46EEE0 · link 0x46EEF0 · longname 0x46EEF8 · type 0x46EF0C · name 0x46EF6C · $(SinglePlayer) 0x46EF34

10. Key data-structure take-aways

1. .nfm and servercycle.txt share one grammar: the GameOS info file format (sections, key=value, Name={ blocks, #define/! directives, $(macro) expansion, ////* */ comments).
2. The format is case-insensitive by default; .nfm files opt out with !preservecase=true. Keys are lowercased on read otherwise.
3. Duplicate keys are meaningful — a map's [ruleset] is a list of repeated type= lines; the parser retains every occurrence and readers take the first match.
4. Game types are a 13-entry enum (0..12, 13 = SinglePlayer) defined by Content\GameTypes.h; the editor's state arrays are sized exactly 13.
5. The writer normalizes output and only emits non-default optional fields — a hand-edited .nfm's formatting/comments are not preserved on save.