Closes#2137.
Even though (when running TWL/AGB FIRM) the SoC is in O3DS mode, and the GPU also is,
as well as most other components behaving as such (external RAM, L2C not usable, etc.),
this is NOT the case for the LCD and adaptive backlight logic which retains FULL N3DS
functionality, including a feature where the window is blended with a given color depending
on the overall relative luminance of that window.
However, Nintendo's own code mistakenly assumes the opposite, and clearly so ("if GPU in N3DS mode"
checks, not passing N3DS extra adaptive backlight (ABL) to TWL/AGB_FIRM). This has implications:
- Powersaving (ABL) settings in TWL/AGB_FIRM is inconsistent with *both* O3DS (because the new RGB blend
LUT has been set to its current value by NATIVE_FIRM) and N3DS (because "pwn_cnt" and "inertia" are missing
their N3DS-only bits)
- "rave party" when booting into TWL/AGB_FIRM or O3DS NATIVE_FIRM without these regs (well, the LUT)
initialized. Easiest way to do so is by leveraging the "DSi autooboot" feature Luma provides. It is worth
noting at least the LUT survives hardware reboots (if Nintendo were using DSi software that was using
TLNC-based reboots, they wouldn't have noticed).
Only touch the autoboot path, for now
Closes#1882.
Whenever power button is held long enough ("force shutdown"), mcu sysmodule
stores a flag in free reg 0. It will clear it next boot.
During that next boot, if that flag was set and if CFG_BOOTENV.bit0 is set
(warmboot/firm chainload, i.e. not coldbooting), then main() will simulate
a "power button held" interrupt (after upgrading mcu fw if necessary -- it
will reboot console after if it has upgraded mcu fw, I guess that's one of
the reasons the flag is there). This obviously cause other processes to initiate
a shutdown.
In the case of autoboot, ns will panic when this happens.
Add config option to autoboot into 3DS and DSi homebrew menu, without
going through Home Menu (nor launching it).
For 3DS homebrew, this requires homebrew built with libctru v2.0.0 or
later (v2.0.0 was released 2.5y ago).
We simulate a "reboot into title" to achieve this. This being said, when
launching stuff like Pokemon US/UM on O3DS, Home Menu reboots into
itself and not the game directly. This will cause Home Menu to crash if
you use this feature and configure it to use a non-default memory layout
(but if you don't, Home Menu will work just fine).
