They are the kernel. They are only specific to the card they were designed to. It's the file name that's specific to the launcher you are using (if you are using one to launch the card).
Otherwise the card's internal rom expects them to have a specific filename if you booted the cart using that internal rom. (aka booting direct from Home Menu for example)
Alright. When downloading my R4 card's kernel from r4i-sdhc.com (The v1.83b on without the "i" mark) there's no _DS_MENU.dat file, so which launcher am i meant to use?
Ok cool. I think my R4i Gold Launcher (which launches some DSTT clones that didn't want to work with official launcher) expect that file name. However if you are going to use my DSTT launcher. Rename the R4.dat file to TTMenu.dat. Since the internal rom isn't being booted, the original file name the card expected is irrelevant. It's only important that you are using the correct firmware for the card.
I've been playing fallout4 all day, I went into a elevator and it kept going, never stopped, waited 5 minutes, must of been a bug. How bout you, whatcha do today?
Otherwise the card's internal rom expects them to have a specific filename if you booted the cart using that internal rom. (aka booting direct from Home Menu for example)