Software information: Raspberry Pi: Firmware (Rev #8, changes)

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Raspberry Pi models supported

The instructions given below are suitable for earlier versions of the Raspberry Pi up to and including the Raspberry Pi 3 (all models, including Compute Module 3+).

The Raspberry Pi 4 is not supported, although work is underway to add support. See Raspberry Pi 4 port status? for more information.

Pi bootloader files

bootcode.bin – The boot loader for the CPU.

start.elf – The GPU firmware. Forms a matched pair with fixup.dat

fixup.dat – Additional code for the GPU. Forms a matched pair with start.elf

riscos.img – The RISC OS ROM

config.txt – Configuration parameters for the boot loader. See below for suggested contents.

cmdline.txt – (Optional) Additional parameters to be passed to the kernel (i.e. RISC OS). See below for possible contents.

Obtaining Pi firmware

RISCIf you have the latest 5.27 OS 5.24 and ROMRISC, there is a good chance that the latest Raspberry Pi firmware will work OS 5.26 should use the firmware supplied with the distribution: there is no point in using later firmware.¹. Visit the Raspberry Pi firmware download site on GitHub to download the latest versions of bootcode.bin, start.elf and fixup.dat.

A Older releases ofcode change in January 2019 means that RISC OS 5.27 cannot use the latest firmwarecannot¹ . use Current the recommendations firmware are: supplied with earlier distributions, but there is a risk in using the absolute latest firmware as recent changes in the firmware could have had a detrimental effect onRISC OS operation.

The files procedure you to need follow are: is: bootcode.bin, fixup.dat, start.elf.

• start.elf Go and to fixup.dat are normally issued as a matched pair, so you should use files released on the appropriate firmware page on GitHub (see above).SAME date where possible.
• bootcode.bin Click is on not “boot”. as heavily constrained, but for maximum peace of mind you should use the release closest in date to the chosen version of start.elf/fixup.dat.
• Click on “bootcode.bin”
• Click on the Download button.
• Click on your browser’s BACK button.
• Click on “start.elf”.
• Click on the Download button.
• Click on your browser’s BACK button.
• Click on “fixup.dat”
• Click on the Download button.

To obtain firmware files:¹ A RISC OS code change in January 2019 means that RISC OS 5.27 cannot use the firmware supplied with earlier RISC OS distributions. Likewise, a Raspberry Pi firmware change in June 2019 means that older RISC OS ROMs cannot use the latest firmware.

Configuration files

config.txt

The contents of config.txt does not change much between RISC OS releases. The following parameters should be suitable for RISC OS 5.24, 5.26 and 5.27:

fake_vsync_isr=1
framebuffer_swap=0
gpu_mem=64
init_emmc_clock=100000000
ramfsfile=CMOS
ramfsaddr=0x508000
kernel=RISCOS.IMG

These parameters – and several others that may be of interest to RISC OS users – are discussed in more detail at config.txt (Raspberry Pi).

cmdline.txt

This file is optional: RISC OS will still boot if it is not present.

If you are running RISC OS 5.27 you may need to specify the following parameter to avoid a blank screen issue.

disable_gamma

Parameters must be space separated on the first line of the file, so if you wanted to specify two parameters you would do it like this:

disable_mode_changes disable_gamma

For details of the parameters available, see cmdline.txt (Raspberry Pi).