FreeRTOS-Kernel VS Atmosphere

Here is the port - https://github.com/FreeRTOS/FreeRTOS-Kernel/tree/main/portable/ThirdParty/GCC/Posix

Freertos has support for generic cortex m3: https://github.com/FreeRTOS/FreeRTOS-Kernel/tree/main/portable/GCC/ARM_CM3 It could very well work almost out of the box with your mcu.

the only OS written in iso c i found was RTOS and they have open bug reports due to strict aliasing in simple things like their linked list implementation, which they don't bother to fix because somehow that causes even more problems (?!): https://github.com/FreeRTOS/FreeRTOS-Kernel/pull/54

You likely put the requirements of POSIX just to have an excuse. Fyi, FreeRTOS kernel, the only thing you need, is here: https://github.com/FreeRTOS/FreeRTOS-Kernel/

- https://github.com/FreeRTOS/FreeRTOS-Kernel (architecture, C)

FreeRTOS comes with 5 quite simple reference implementations of the heap memory allocator. You can study how it works.

The main branch is single-core. You're looking for the SMP branch.

On non-POSIX systems, malloc & free are implemented differently. EG FreeRTOS has some very simple malloc (and optionally free) implementations, eg heap_2.c (has malloc & free, but doesn't consolidate blocks), or heap_4.c (more complex, tries to prevent fragmentation by consolidating blocks, still less optmized & simpler than the glibc malloc/free used by most Linux systems).

Knock yourself out: https://github.com/Atmosphere-NX/Atmosphere/releases

The Nintendo Switch is a great console for sideloading. There are numerous ports of PC titles like Quake and Half-Life, as well as a library of Homebrew games and modding tools. If you've got an original Nintendo Switch there's practically no excuse not to crack it, unless you intend to play online.

Same goes for the 3DS, too. You can now play Virtual Boy games using the built-in 3D screen, which enables preservation of Nintendo's darkest age (with or without their approval). I have soft-modded versions of both the Switch and 3DS, and recommend it to anyone that wants that experience.

If you want an Xbox or Playstation console, buy the SOC from AMD. They sell them on Alibaba and get the same support Microsoft and Sony recieve (read: dogshit). Most people would agree that it's wiser to not use console hardware for PC software when you can build a superior machine for a lower price. But hey, if you wanna waste time and money be my guest.

Official Atmosphere documentation on Exosphere states:

SOLVED, I needed to use this pre-release version of atmosphere. https://github.com/Atmosphere-NX/Atmosphere/releases/tag/1.5.4

This might be a good source https://github.com/Atmosphere-NX/Atmosphere/releases

Not yet, but there is an Atmosphere feature request for it.