System Menu

The System Menu (DSi Menu) is software shipped pre-installed on every DSi which allows the launching of games from official Nintendo certified game carts, "channels", or DSiWare titles. It runs a GUI similar to the Wii's "Wii Menu". The DSi runs in permission modes similar to the Wii, where running in backwards compatibility mode turns off extra hardware and down-clocks the CPU. Using the power button you can soft reset to return to the menu while in game (or in a DSi application), similar to the "Home Menu" on the Wii. Game carts can also be hot-swapped while in the menu.

Unlike on the Wii, where channels could return to the Wii Menu with ES_LaunchTitle(1-2), software never returns to the DSi Menu. Instead, the system reboots to boot0, therefore reloading Unlaunch.

Autobooting paths

When the System Menu loads, it has 3 methods of automatically booting a title before it loads the main UI.

Reset launching

First, the System Menu checks if the title ID at 02ffd204 is not 0-0, and boots that title if possible. This is presumably how apps like Photo Clock are able to launch titles.

Cart autoboot

This method is used when holding the key combination A/B/X/Y/R.^[check] There are other checks in place before the autoboot is done.

Screen calibration

If the key combination START/L/R (not X/L/R) is held on boot, then the system boots to the System Settings screen to calibrate the touch screen.