uses of flash carts/kernels

Can somebody help me on how to update or use flash carts in emulators?

flashcarts cant be used on emulators. but if you want to use emulators on you flashcart than you can, you can run nes and snes emulators ok. to update your flashcart, it really depends on which one you have

AlicezhouAs far as I know, the dstwo card can run emulators. Just download the latest firmware v1.17 and DSTWO EOS v1.11,
unzip it, put the files in the root of SD card, then download the dstwo plugin, unzip it, put the files “_dstwoplug” and “NDSGBA” into your SD card.
More details, just have a look at here: http://www.oz3ds.com/product.php?id_product=25

He didn't mention what his cart is, so I guess you must possess psyhic power. :P

Vitally you can use a Vital R4 flashcard on DeSmuME along with either woodR4 are YSMenu firmware, original only.However it will not play the games. only dump the firmwares memory into RAM. So we can get games AP fixes of woodr4 and ysmenu.
---------------------------------But lets no confused the lad ;)I think maybe.... he means use a well unsure I'm confused also ???

only DSTwo can run a GBA emulator, as far as I know any flashcart can run the other emulators.