Delete me: Installing RISC OS on the Raspberry Pi 4 (Rev #7)

Pi 4B

The current stable release (RISC OS 5.28) can be used on the Raspberry Pi 4B.

You will need the following items:

• A 2GB (or larger) MicroSD card
• The RISC OS Pi image (version 5.28) from the Downloads page

Unpack the RISC OS Pi archive and use a utility such as Win32DiskImager (Windows) or Etcher (Linux/macOS) to copy the image to the MicroSD card. This will create an SD card in a suitable format, but only the first 2GB of the card will be usable by RISC OS.

See below for usage instructions.

Pi 400

The Raspberry Pi 400 was launched after the release of RISC OS 5.28, so the pre-built “RISC OS Pi” image won’t work out-of-the-box. If you wish to proceed, the following instructions will allow you to boot RISC OS 5.29 on the Pi 400.

Please bear in mind that RISC OS 5.29 is untested, work-in-progress software.

You will need the following items:

• A 2GB (or larger) MicroSD card
• The RISC OS Pi image (version 5.28) from the Downloads page
• The latest Beta RPi ROM (BCM2835Dev), also from the from the Downloads page just mentioned.
• October 2020 (or later) firmware (fixup4.dat, start4.elf) – see Software information: Raspberry Pi: Firmware for details.

Unpack the RISC OS Pi archive and use a utility such as Win32DiskImager (Windows) or Etcher (Linux/macOS) to copy the image to the MicroSD card. This will create an SD card in a suitable format, but only the first 2GB of the card will be usable by RISC OS.

Once the SD card image has been written, proceed as follows:

• Unpack the BCM2835Dev archive. This will give you a file called “riscos.img”.

• Open the first (or only) partition on the MicroSD card. This should show the contents of the boot partition, including “riscos.img”. Delete this file, and replace it with the “riscos.img” file from the BCM2835Dev archive.

• Replace “fixup4.dat” and “start4.elf” with the revised versions you downloaded.

Card preparation is now complete. Remember to dismount the SD card before unplugging it.

Using the SD card in the Pi 4B / Pi 400

1. Connect a suitable power supply to the USB-C (power entry) port.
2. Connect a mouse to one of the USB ports.
3. (Pi 4B only) – Connect a keyboard to one of the USB ports.
4. Connect the HDMI cable to the HDMI port closest to the SD card slot.¹
5. (Optional) – Connect the Ethernet port to your broadband router (or equivalent network port with Internet access).
6. Insert the SD card into the Pi and power on. If all is well, the system will boot² to the RISC OS desktop at the monitor’s native resolution (e.g. 1920×1080).

With some monitors (particularly 4K monitors) you may find that the desktop is displayed at a low resolution (e.g. 640×480). You can increase this to 1920×1080 via Configure > Screen in the usual way.

¹ If you connect it to the other port you will get a picture but no sound.

² It can take 30-40 seconds for the boot-up progress screen to appear. You should be at the RISC OS desktop some 50 seconds after powering-on (roughly twice as long as it takes on a Pi 3).

Further information

See Using RISC OS on the Raspberry Pi for information applicable to all models of Raspberry Pi.