Software information: Raspberry Pi: Firmware (Rev #6, changes)

Showing changes from revision #5 to #6: Added | Removed | Changed

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

bootloader.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

RISC OS 5.24 and RISC OS 5.26 should use the firmware supplied with the distribution: there is no point in using later firmware.

A code change in January 2019 means that RISC OS 5.27 cannot use the firmware 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 on RISC OS operation.

The current recommendation is to use January 2019 firmware obtained with from thedownload siteRISC OS 5.27.

The files you need are: bootcode.bin, fixup.dat, start.elf.

• start.elf and fixup.dat are normally issued as a matched pair, so you should use files released on theSAME date. date where possible.
• bootcode.bin is not 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.

To obtain firmware files:

• Visit the download site on GitHub.
• Choose a component (we suggest you use start.elf) and click on the History button.
• Find the date you are interested in and click on the “<>” button at the extreme right of the line, which takes you to the firmware front page for that day in history. If you are having problems, this link will take you to the page for 22 January 2019.
• Click on “boot”.
• 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.
• Click on your browser’s BACK button.
• Click on “bootcode.bin”
• Click on the Download button.

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).