RAK 2287 Diy gateway

is it possible to build a gateway using the basics station on a rak2287 and rpi platform. what are the other options apart from balena which can be used to setup a gateway. My end goal is to replace the rpi with a custom embedded device.

There are several existing threads on this here you can find with the search function, or simply looking through this topic area of the forum.

is it possible to interface the rak 2287 with an embedded board other than raspberry pi ?
if yes, then which firmware i must be using?

Again, see the existing threads on this.

If you are going to build a custom gateway, you should start with understanding of the lora hal and packet forwarder which must be compiled for (or in an extreme case, ported to) your embedded system.

One of the things you’ll see discussion of in the existing threads is the slight software differences needed between the RAK2287 and the SX1302 reference design from the chip vendor who is also the upstream author of the needed software. That’s particularly true if using the basicstation version of the packet forwarder, as you said you wanted to - someone just worked through that for a custom setup a week or two ago, and their thread would a useful reference for you.

You might find it easiest to do some initial tests on a pi before moving the card to another platform with good SPI support.