When i boot, it gives only some messages to the point where it reads the "config.txt" but says "Firmware not found"
config.txt is read by the early bootloader, not the kernel, so this might apply to the contents of
/boot. You do not say what else you've put in there, but a kernel and a
config.txt file are not enough. What's supposed to be there can be found at https://github.com/raspberrypi/firmware/tree/master/boot.
If you are sure that's not the issue because you created and populated the boot partition properly, firmware used by the linux kernel goes in
/lib/firmware. This is distinct from and unrelated to the firmware in
/boot used before or when the kernel is loaded; it is loaded subsequently as needed (generally by device drivers). Some of it is (or can be) built and installed with the kernel but some of it comes in separate packages (on RpiOS/Debian look at
apt-file search /lib/firmware). In any case, it isn't used by the CPU so not bound to specific platform architectures; it's the same everywhere and usually distributed as binary blobs.
/lib/firmware is used by any kernel for reasons just mentioned, but you also need a version specific module directory in