Created attachment 6286 [details] last lines of stdout on the failed execution On building using raspberrypi_defconfig configuration and changing the endianness to big endian, the buildroot fails to finish the build as attached files describe in detail.
You can't just change endianness arbitrarily and expect that to work. For starters the pre-compiled rpi-firmware required for the boot process is only enabled for little-endian, which gives you the error you're seeing because it's not installed for big-endian. I don't have much technical detail about the broadcom SOCs used in the rpi1/2 and how open they're to changing endianness, some SOCs require hardware changes (pin bootstrap), others can be switched in the bootloader, others use fuses and some can't be changed. Even if they could be switched in the bootloader for the rpi boards that's a propietary blob in rpi-firmware, so there's not much you can do. I'm closing this as invalid.