Hacking question about GC fuses

[brollikk]

so I was reading up on 9.0 and learned that it burned GC fuses. Just to clarify, this is different than the firmware fuse right? And this is what determines if you can run gamecarts on below 9.0? I am a little bit unclear on that last bit - When you update a switch to 9.0 normally and burn GC fuses, what can you not play? XCI/NSP on earlier patches that did not require 9.0? In the future, will using xci/nsp with "ignore firmware requirements" still allow us to play normally or will we have to update all games with the newest patch (basically re-do the vast majority of a custom/super xci collection) ?

 

[MichiS97]

Having a GC fuse burnt and the cartridge reader firmware updated means that you won't be able to play original cartridges on a firmware lower than 9.0

 

[brollikk]

Having a GC fuse burnt and the cartridge reader firmware updated means that you won't be able to play original cartridges on a firmware lower than 9.0

What do you mean “original cartridge on a firmware lower than 9.0”

Specifically do you mean if the game cart comes with lower firmware requirements? Or what?

 

[gratefulbuddy]

Sounds to me like - if you were to downgrade your fw >9.0.0 then you would forfeit oem game cart usability

 

[pcwizard7]

Original cartridge = physical cartridges and not xci/nsp files

 

[Amingo]

Someone in the big SX OS 2.9 thread suggested that the GC fuse actually only gets burned if you insert a gamecard after updating to 9.0.0. So maybe if you haven't put in an original card under 9.0.0. the fuse could still be fine.

 

[brollikk]

Can anyone chime in about how this affects custom xci?

 

[proffk]

I wonder if there's any clarity on this. Does 9.0 FW burn gc fuse if you update offline with AutoRCM. And does SX OS 2.9.1 beta burn gc fuse when mounting XCI. I already know inserting a actual game cart will burn the gc fuse but according to this tweet it does.

Oh and beware, due to improper update of the XCI loader, this will burn the 9.0.0 Gamecard ASIC's fuse, so downgrading afterwards will render gamecards unusable on both system and emulated NANDs.

— Mike Heskin (@hexkyz) September 28, 2019