Binaries and versions

The game's binaries

The executable, SLES_039.36 in the European release, SLUS_014.36 in the USA one and SLPS_034.46 in the Japanese one, holds the engine and the PsyQ libraries. The rest of the game is in overlays, AAA/PRO/*.PRO on the disc, which load right after the executable's .bss. Every engine module is a global struct holding its state and a table of methods (GFX, HEAP, FILE_CACHE, PAD, SOUND, GAME...), and every game object is a task (createTask, include/engine/task.h); the overlays reach the engine through those tables. Each overlay has its own splat config, source folder and symbol prefix (CNTY_SEL_, STDWTITL_...):

Overlay	Loads at (us)	Functions in C (us)	What it runs
CARDGAME	0x80082448	306 / 306	the card battle (mode 0x700): the decks, the cards in play and the battle screen
CNTY_SEL	0x80082448	26 / 26	the country select screen
FIELDSTG	0x80082448	222 / 222	the field mode, where the player walks around the map; the stages load on top of it
FIGHTSTG	0x80082448	297 / 297	the battle: the fight stage and its lights, the fighters' models, faces and cameras, the battle camera and windows, the queue of battle events and the stat, hit and status checks
SHOCKTST	0x80082448	17 / 17	the debug vibration test
SOUNDTST	0x80082448	8 / 8	the debug sound test
STAGSLCT	0x80082448	8 / 8	the debug stage select, a menu of every scene of the game
STCRDABM	0x80082448	29 / 29	the card album
STCRDDEK	0x80082448	55 / 55	the decks, which it names with the on-screen keyboard (include/shared/name_entry.h)
STCRDSHP	0x80082448	45 / 45	the card packs (mode 0x1300): opening a pack uses it up and draws six cards, one from each slot's list in STCRDSHP_packs
STDGNAME	0x80082448	32 / 32	a name entry screen, a keyboard of character pages
STDWTITL	0x80082448	74 / 74	the title screen, the opening movies and a notice screen
STFGTREP	0x80082448	36 / 36	the report after a battle (mode 0x1400), which WFIGHTMN requests: the partners that went up a level
STGDGLAB	0x80082448	70 / 70	the partners' digivolutions, it seems: a menu of three screens that checks the recipes of STGDGLAB_data against a partner's entries and sets its three slots
STGMCARD	0x80082448	45 / 45	the memory card screen (mode 0xC00): the saves of a card, their details, and saving and loading
STGTRAIN	0x80082448	94 / 94	the gyms: a partner trains a stat, gaining some and losing others, with its sprites and the result windows
STITSHOP	0x80082448	69 / 69	the item shop, where the player buys and sells items and equips what was bought on a partner
STPLNMET	0x80082448	53 / 53	the player's name entry (mode 0x500), with a copy of STDGNAME's keyboard
STSTATUS	0x80082448	123 / 123	the screens the field menu opens (STSTATUS_screens), such as the item list and the equipment
WFIGHTMN	0x800A4CA4	42 / 42	the battle's sub-overlay, which FIGHTSTG loads (file 0x1FA) for a normal battle: it checks the party and its equipment and ends the battle
WFIGHTTS	0x800A4CA4	14 / 14	the debug battle test, which FIGHTSTG loads (file 0x1FB) in place of WFIGHTMN: lists of fighters, motions, effects and stages
WSTAG### (238)	0x800A4CA4	1,369 / 1,369	the stages: small programs that load on top of FIELDSTG and call into it

SMDLDATA, SDIGIEDT and SFSTDATA hold no code and aren't built. WSTAG260 has no code either, only the story events' scripts that FIELDSTG runs, and builds from its C data. The disc's AAA/DAT, AAA/PRO and AAA/STR directories are only reachable through the ISO 9660 path table, which is why tools/extract_disc.py is needed: dumpsxiso doesn't see them.

The executable's game code is in modules (src/engine/<module>/, see CONTRIBUTING.md), cut from its original objects in their link order:

Original object	Files	Address (us)
crt0	asm/<version>/main/crt0.s: PsyQ startup (2MBYTE.OBJ), splat's disassembly	0x80010EBC-0x80010F80
inn	menu/inn.c, gfx/screen_fade.c	0x80010F80-0x800120B8
system	menu/field_menu.c, game/digimon.c, game/items.c, file/cd_reader.c, file/file_cache.c, file/file_table.c, task/task.c, system/main.c	0x800120B8-0x80014818
memcard	memcard/memcard.c (and system's last function, initMemCard)	0x80014818-0x800154F8
game3	game/events.c, game/state.c, game/party.c, game/play_time.c, game/stats.c	0x800154F8-0x800172E8
game3_2	game/partner.c, system/heap.c, task/registry.c	0x800172E8-0x80017FAC
pad	pad/pad.c, pad/demo.c, pad/port.c, system/random.c	0x80017FAC-0x80018FEC
text_window	text/text_window.c, text/cursor.c, file/decompressor.c, text/message_box.c, text/talk_box.c, text/font.c	0x80018FEC-0x8001D070
graphics	gfx/display.c, gfx/layer.c, gfx/card_drawer.c, gfx/sprite_drawer.c, text/text_tools.c, gfx/tim_loader.c	0x8001D070-0x8001FC68
sound	sound/sound.c	0x8001FC68-0x80020764
overlay	system/overlay.c	0x80020764-0x80020998
psyq	asm/<version>/main/psyq/: the PsyQ libraries, splat's disassembly, one file per library object	0x80020998-0x8003E9D8

Memory maps (psylink puts .rodata in front of .text):

	us (SLUS_014.36)	eu (SLES_039.36)	jp (SLPS_034.46)
.rodata	0x80010000-0x80010EBC	0x80010000-0x80010E88	0x80010000-0x80010E68
.text	0x80010EBC-0x8003E9D8	0x80010E88-0x8003EDCC	0x80010E68-0x8003EBF8
.data	0x8003E9D8-0x8005C480	0x8003EDCC-0x8005CCE8	0x8003EBF8-0x8005CA98
.bss	0x8005C480-0x80082448	0x8005CCE8-0x80082CB0	0x8005CA98-0x80082A60
$gp	0x8005C2F8	0x8005CB50	0x8005C90C
Overlays (OVERLAY_VRAM)	0x80082448	0x80082CB0	0x80082A60
Stages, WFIGHTMN, WFIGHTTS (STAGE_VRAM)	0x800A4CA4	0x800A5DE0	0x800A5770

A 320x480 16-bit TIM image is loaded together with the program, so the executable stores .bss and the gap after it as zeros; splat keeps that tail as assets/<version>/tail.bin. STAGE_VRAM is right after CARDGAME, the largest overlay.

How the versions are organised

One source tree builds every version, one at a time, picked with VERSION (eu by default):

VERSION	Release	Executable (SHA-1)	Disc image (SHA-1)	Overlays	Stages	C
us	Digimon World 3, USA, SLUS-01436	SLUS_014.36 (444653259f78ddb483fd22af72cce9276f42f214)	Digimon World 3 (USA).bin (f0b022f9be53cbce14640abd8f01beaadcb35208)	21	238	yes
eu	Digimon World 2003, Europe, SLES-03936	SLES_039.36 (d1b7e4d646e3a9c2b88fdb25d20b5f7116bbb06d)	Digimon World 2003 (Europe).bin (457cb233349ba841e03b33d8060f8fbcadd45cb3)	21	293	the USA version's, and its own stages'
jp	Digimon World 3: Aratanaru Bouken no Tobira, Japan, SLPS-03446	SLPS_034.46 (0e5b6b9ee2f99a804ed8c4117c805482c10e260b)	Digimon World 3 - Aratanaru Bouken no Tobira (Japan).bin (8594fb44f601da64087a8996ffd89ab26abb11ea)	21	293	the European version's

• mk/version/<version>.mk has each version's settings: the release's name, the executable's name, the disc directory, the overlays, where they load (OVERLAY_VRAM, STAGE_VRAM) and the C files it builds (C_SRC). The Makefile builds nothing else. tools/version.py reads the same file, so every tool follows VERSION too.
• config/<version>/ has its splat configs (main.yaml, <overlay>.yaml), symbols (symbols.txt, symbols_<overlay>.txt), the list of stages (stages.txt) and the checksums (<executable>.sha1, overlays.sha1, stages.sha1). The generated asm/<version>/, build/<version>/, expected/<version>/ and assets/<version>/ are kept apart too.
• The stages have no config file each: config/<version>/stages.txt lists them with the offsets where their code starts and ends, and tools/stage_yaml.py writes their splat configs into build/<version>/generated/stages/. A stage marked asm there keeps its code and data in asm segments until it has a C file in that version; one marked asm-data only its data: no stage of any version is marked either now. c-rodata takes the bytes before the code, a color or jump tables, from the stage's C file too. head-word takes WSTAG924's first word from a C file of its own, src/field/stages/amaterasu_city/wstag924_head.c, linked before the stage's jump tables (which GCC would align to 8 bytes after it). data marks the stage with no code, WSTAG260, all of it its C file's data (data asm: splat's assembly). The last bytes of a stage that ends inside a word are a databin of their own while its data is asm, which tools/inputcheck.py lets link as it is shorter than a word.
• The C sees VERSION_US, VERSION_EU and VERSION_JP, each 0 or 1 (include/version.h), and so does the assembly (--defsym). Code tests them with #if VERSION_EU, never #ifdef; CONTRIBUTING.md has the rules.
• us builds every C file under src/, and eu builds them all too (C_SRC), with #if VERSION_EU blocks where its code or data differ. Its executable and overlays are split into the USA version's files, so its asm lands at the same paths (asm/eu/main/game/events.s for asm/us/main/game/events.s). Its stages that the USA version has build from their C files (config/eu/stages/<stage>.txt gives their functions the USA names), and so do its own, whose functions are C where they are the code of a USA stage's C. The European release has the USA one's 21 overlays and 238 stages plus 55 stages of its own (WSTAG920-974).
• jp builds every C file too, with VERSION_JP in the tests of the blocks: the European release was made from the Japanese one, so the Japanese code and data are mostly the European ones (its 55 extra stages, the scripts the USA version left as they were), with LANGUAGE 0 and no PAL video, at the USA disc's file numbers (include/engine/file.h), its text the Japanese copies of the USA text files. Its executable and overlays are split into the USA version's files (tools/split_version.py), its WSTAG920-974 take the European names (config/jp/stages/wstag9NN.txt). Only the PsyQ SDK and libpress (asm by policy) and crt0 are assembly. The Japanese release has the same overlays and stages as the European one, each a little different in size.
• The versions share their names: the European and Japanese symbol files hold the USA names of the functions and data paired with the USA version's (tools/match_versions.py), and tools/check_names.py checks that they stay the same.