3dsImageCreator

This repository contains an experimental Nintendo 3DS game card dumping and header inspection tool.

Requirement

• CFW

Development tool

• devkitARM(https://devkitpro.org/wiki/devkitARM)
• python(https://www.python.org/)
• firmtool(https://github.com/TuxSH/firmtool)

Current focus

• Read a 3DS game card into split .3ds output on SD when required.
• Export parsed NCSD, CardInfo, InitialData, NCCH, ExeFS, and RomFS metadata to a text report.
• Decode ExeFS and RomFS metadata needed for inspection reports.
• Keep implementation decisions traceable to public documentation and hardware-observed behavior.

Public references used

• GBATEK documentation(https://problemkaputt.de/gbatek-3ds-reference.htm) for 3DS cartridge protocol and file formats.
• 3dbrew documentation(https://www.3dbrew.org/wiki/Main_Page) for NCSD, NCCH, ExeFS, RomFS, and NCCH encryption layout.
• Behavior observed on retail hardware during this project.
• FatFs, included under its own permissive license in fatfs/LICENSE.txt.

Source layout note

• source/dump3ds_formats.c / include/dump3ds_formats.h - NCSD/NCCH/ExeFS/RomFS structure helpers and little-endian accessors.
• source/dump3ds_aes_ctr.c / include/dump3ds_aes_ctr.h - AES-CTR helper routines for the hardware AES block.
• source/dump3ds_secure_init.c / include/dump3ds_secure_init.h - card secure-session seed preparation and secure seed loading helpers.
• source/dump3ds_header_report.c / include/dump3ds_header_report.h - header/report text output, ExeFS/RomFS inspection, and RomFS listing helpers.
• include/dump3ds_cardio.h - small interface used by the report code to call the card read/recovery functions implemented in source/main.c.
• include/dump3ds_config.h - shared compile-time constants used across the split files.

The existing recursive Makefile style that builds all source/*.c files should pick these files up automatically.

Documentation basis for source comments

Source comments use the following categories:

• Public file-format descriptions: NCSD, NCCH, ExeFS, RomFS and IVFC layouts from 3dbrew and GBATEK.
• Public hardware descriptions: 3DS gamecard, CTRCARD and AES register notes from 3dbrew and GBATEK.
• Hardware-observed behavior: register write ordering, polling margins and retry thresholds that are not fully specified by public pages, validated on retail hardware by observing expected NCSD/NCCH headers, ExeFS entries and RomFS IVFC data.