TWL Slot-1 Launcher 3DS

TWL Slot-1 Launcher
General
Author	Apache Thunder
Type	Other Apps
Version	3
License	Mixed
Last Updated	2016/02/16
Links
Download
Website

TWL Slot-1 Launcher is a homebrew application that allows you to run blocked DS cartridges and flashcards on DSi and 3DS.

Many older DS flash carts get blocked by CTR mode (most likely by Process9 of NATIVE_FIRM). You can tell if you see it error almost instantly when trying to boot your flashcart. This app gets around that. Any flashcart that hasn't worked since 1.0 launch firmware can be used with this launcher. Note that some flashcarts may work without this launcher with just the TWL_FIRM patches alone. Test that first before using this launcher. If your card works with just the patches, do not report that as that no longer pertains to my launcher. This launcher is intended for DS flashcarts that get blocked by CTR mode.

You can tell if yours is blocked by CTR mode by attempting to boot it from home menu. If you see the "Error has occured" screen pop up almost immediately without the screens flickering on and off, then it is a card blocked by CTR mode. That's what this launcher is for.

Note from developer:

TWL_FIRM MUST be sig patched before this will boot. The sig patches added also patch out DS Cart White List and save chip detection. So if your DS Flashcart already works thanks to that patch, then you don't need this. If you happen to have a prepatched TWL_FIRM installed, that will work too.

User guide

How to use

To use this, simply insert your previously blocked DS flashcart into the game card slot, then boot this application.

Older flashcarts that don't have valid icon/banner data still will not work, notable examples are the original R4 and older hardware revisions of the original Action Replay for DS.

Anything that behaves like a normal cartridge should be bootable with this method (though the cartridge does not fit well in the slot and you have to keep it pressed in a certain position so that it recognizes it).

If you get an error on boot, double check that you have TWL_FIRM patched either via preinstalled CIA or via rxTools (or a future CFW that add the new patches) before reporting that your flashcard doesn't work with this.

How it works

It's a stripped down DSi Extended header with dummy data for the arm7/arm9 sections (they aren't needed as it launches slot-1 before ever getting to load them).

Inserted a custom banner and set the file type at offset 0x234 to 00.

This tells TWL_FIRM that it's a cartridge (even though it's not) and tricks it into booting older flashcarts because the 3DS boots into TWL_FIRM expecting to load this this DSiWare SRL.

But because the file type in the TID field is set to cartridge, it immediately boots what ever is in slot-1.

Media

TWL Slot-1 Launcher (First custom DSiWare app) (ApacheThunder)

Compatibility

Confirmed list of carts working with this:

AceKard 2i
AceKard 2.1
AceKard RPG
R4i-SDHC
iTouchDS2
R4i SDHC Dual Core
Supercard DS One v3 SDHC

Changelog

Update

• Download link updated. Minor changes to header and brought SRL closer to proper SRL spec.

Credits

Credit goes to TuxSH and Steveice10 for finding the sig patches for TWL_FIRM.

Also credit to TheStoneBanana for accidently discovering this odd little quirk of TWL FIRM.

External links

• GBAtemp - https://gbatemp.net/threads/twl-slot-1-launcher-first-custom-dsiware-app.414501