Question: Real Firmware Requirement Checking

[bluedart]

I'm just curious about this since I've not been able to find any concrete information on this yet. In theory, if you open up an .nsp game/update with NxFileViewer, what information could tell what—in practice—would prevent a game from actually installing/running on 18.0.0 atmosphere. These numbers aren't entirely important in and of themselves, I'd rather just know what I need to look for that indicates a firmware update is hard required for custom firmware.

The "Minimum system version" is frankly useless, as many games and updates requiring up to at least 19.0.0 will still run on 18.0.0 cfw in practice. There are more pieces of information on the "Content" tab, and I'm hoping that something there will give me a definitive answer without having to delve past theory crafting. There are sections that list "SdkVersion", which I was thinking might be it. From what I can tell updates seem to use the same version as the base game, even with base games that are years old—like the new 1.6 update for Stardew Valley. The same seems to go for "KeyGeneration". The only exception is the "Meta" contents which seems to use a higher sdk based on what a non-cfw Switch would actually have. Is this "meta" section ignored in practice because of the cfw and installation method, and if so will it require higher sdk/Key Generation values in non-meta sections to prevent them from running on lower firmware in practice?

If anyone knows the exact information on this, especially if I've been looking in the wrong place, I'd really appreciate knowing this.

 

[thesjaakspoiler]

This is my take on it :
The SDK version requirement makes sure that the game doesn't call anything that isn't supported in the firmware.
So in theory, if you are on the right SDK version and won't encounter any bug that might be fixed in a newer firmware,
you should have no need for upgrading the firmware.
I vaguely recall that the CFW does not check the firmware requirements.
Sometimes I see people mentioning that games run fine on a lower firmware than advertised.

 

[fvig2001]

I mean SDK version is probably the best way to check. I guess you can check something like Smash/Mario Kart 8's latest updates. These still work on 11.0 last time I checked.

 

[Deleted member 702243]

if you use fusée to boot, even games requiring higher master key than your firmware will run, as long as the sdk used is not higher than your firmware version. for what it's worth

using hekate, you would need to rebuild the file for lower master key if not upgrading firmware