dlpdump – DS Download Play Dumper

This is a Nintendo DS homebrew project for preserving DS Download Play content in a verifyable way. It behaves like a local DS Download Play program, captures the transmitted multiboot payload, reconstructs it as a bootable .nds and .bcn file combination, and writes useful sidecar files for diagnostics and reproducibility.

A dump report will be automatically generated with CRC32, MD5, SHA-1 and SHA-256 hashes and various useful information related to the dump. The program can take advantage of TWL mode to calculate these hashes faster; tested on a DSpico.

Usage

Copy dlpdump.nds to a DLDI-capable flash card’s storage media and run it on DS-compatible hardware. After startup, the application creates /dlpdump, scans automatically for DS Download Play hosts, and starts suitable downloads on its own.

For RSA signature verification, provide the 128-byte DS Download Play public key as /dlpdump/pubkey.bin on the flash card storage media. The key is not redistributed with this project. Its SHA-1 hash is 78cca7e87c5f8e1f1eddfe57d7755e7b3de5232e. RSA signature verification validates the integrity of a dump. Validated dumps can then also be launched.

Button	Action
B	cancel the current download; skip generating a dump report
START	launch the most recent saved dump if a matching .nds/.bcn pair exists and RSA signature verification passes
X	toggle repeated downloads of already saved content
L+R+A+B+DOWN	exit the application

Output files

All files are written to /dlpdump. The base filename contains a timestamp and title, for example YYYYMMDD-HHMMSS - <Title>.

File	Contents
.nds	reconstructed ROM file (consisting of header, ARM9 and ARM7 parts and the RSA signature, all carefully placed in the areas as specified by the header data)
.bcn	broadcast context (icon graphic, game title, game description, host name, game group ID and user parameters for later booting)
.txt	human-readable dump report with CRC32, MD5, SHA-1 and SHA-256 hashes, decoded ROM header data, broadcast context, and transfer counters

Only created by the debug version:

File	Contents
.pcap	IEEE 802.11 diagnostic capture of relevant beacon and download traffic; should not be shared as it may include personal data
.log	log file for debugging purposes

Build

Requirements:

• devkitPro / devkitARM
• libnds
• Calico DS libraries
• ndstool
• Python 3 for generated assets

export DEVKITPRO=/opt/devkitpro
export DEVKITARM=$DEVKITPRO/devkitARM
make

The debug version for diagnostic purposes can be built with make debug.

Disclaimer

Use the program only for your own authorized backup, analysis, interoperability, and compatibility testing. Respect local laws and the rights attached to games and transmitted content. The main reference used is GBATEK by Martin Korth. This project does not include original Nintendo code. GPT-5.5 was used as a coding assistant in this project.

License

The main project code is licensed under GPL-3.0. Third-party and derived components are listed in THIRD_PARTY_NOTICES.md, including Calico-related files and Pico Loader-based boot/handoff code.