1ġ You may have to alter network settings, as the Pi 4 uses a different Ethernet interface.
SHOULD I DELETE BOOT.ELF INSTALL
If you install bootcode.bin, start.elf and fixup.dat alongside start4.elf and fixup4.dat, the card will boot on older models of Raspberry Pi as well as the Pi 4. Note that the Pi4 has its boot code in the onboard EEPROM so it does not need bootcode.bin. fixup4.dat – Additional code for the Pi 4 GPU.On the Pi 4 (and Pi 400) the following two files take the place of bootcode.bin, start.elf and fixup.dat: cmdline.txt – (Optional) Additional parameters to be passed to the kernel (i.e.config.txt – Configuration parameters for the boot loader.fixup.dat – Additional code for the GPU.bootcode.bin – The boot loader for the CPU.The Pi 1, Pi 2 and Pi 3 use the following files: shift-doubleclick on !Boot and then double-click on the file called “Loader”). On a standard RISC OS build using a Dual-format SD card, this can be reached by double-clicking on !Boot.Loader (i.e. The Raspberry Pi bootloader files live in the DOS partition of the boot SD. The instructions given below are suitable for all models of Raspberry Pi, including the Pi 4B and Pi 400.