Minimal flashcart bootstrap for NDS consoles. Loads /BOOT.NDS and
papers over various device-specific quirks, allowing running 100%
clean homebrew launchers on a variety of such devices.
Copy the contents of the specified directory to the root of your flashcart's memory card:
| Device | Directory |
|---|---|
| Ace3DS+ / Ace3DS X | ace3dsplus |
| Acekard 2/2i | generic |
| Datel Games 'n' Music | generic |
| DSTT | generic |
| EDGEi | generic |
| EZ-Flash Parallel | generic |
| EZ-Flash V | generic |
| Gateway Blue | gwblue |
| R4 (original) | generic |
| R4 i.L.S. | ace3dsplus |
| R4/R4i Ultra | r4itt |
| R4iDSN | r4idsn |
| R4iTT 3DS | r4itt |
| r4dspro.com | r4dspro |
| r4ids.cn | r4itt |
| R6 Gold/Silver | mkr6 |
| Stargate 3DS | stargate |
| SuperCard DSONE | generic |
| SuperCard DSONE SDHC | dsonesdhc |
| Timebomb carts | generic |
Hold START while loading to enable debug output. Note that launching will only continue once you release START.
To build miniboot, the Wonderful toolchain's
wf-tools, toolchain-gcc-arm-none-eabi, as well as BlocksDS (for
ndstool and dldipatch) are required. They can be installed with the
following command:
$ wf-pacman -Sy toolchain-gcc-arm-none-eabi thirdparty-blocksds wf-tools
.nds files can be loaded essentially anywhere in RAM: in particular,
3.75MB out of the 4MB of main RAM can be used. As such, the easiest
way to load such a file is to put the bootstrap code outside main RAM.
As the fastest place to execute code from is ITCM, I started wondering if one could create a bootstrap that operates entirely from ITCM (32K) and DTCM (16K). That is not a lot of room - the DLDI driver which is provided by a flashcart vendor has to have 16KB of space reserved, leaving only 16KB for the remaining code. Thankfully, there's not much code involved: one needs a lightweight copy of FatFs to read files from the filesystem, a DLDI patcher for the loaded ARM9 binary, and some simple load/reset code on top of that.
I've also never created a freestanding NDS homebrew program before, so I wanted to see what goes into that.
Assorted notes:
arm9.binandarm7.binare extracted from the ELF file as they are position-independent - the binaries relocate themselves upon execution to areas outside of main RAM, they just have to be started from their first word (offset 0).- Initiailization is deliberately sparse; if a given device needs additional cleanup, please document it!
The miniboot source code itself is covered under a mix of two licenses:
- the Zlib license,
- the FatFs license.
Individual binaries for specific flashcarts may be covered under their own respective licenses.