Raspberry Pi: RISC OS boot-up issues

Introduction

This page details some of the problems you may experience when trying to boot-up RISC OS for the first time on a Raspberry Pi.

The suggestions given here assume that a recent “RISC OS Pi” image is being used, either downloaded from this site or installed via Raspberry Pi Imager.

Blank screen (or Pi “rainbow” screen)

On older models of Raspberry Pi (Pi Zero, Pi 1, Pi 2, Pi 3) boot-up can get stuck at a completely blank screen, or at a “rainbow” screen with no text.

The Activity LED may be flashing a distinct pattern (a number of short flashes followed by a number of long flashes). For what these mean, see LED warning flash codes.

• The most likely problem is the SD card itself. Check it is seated correctly, check that the contacts in the card slot aren’t damaged in any way, clean it all up, and try again.

• If the LED warning flash code indicates a problem with a firmware file (and cleaning the contacts on the SD card/slot hasn’t worked) you can try updating the firmware as described here.

You should not see the “rainbow” screen on a Pi 4B or Pi 400: you should instead see the boot diagnostics screen (see below).

Pi 4 “boot diagnostics” screen appears

On a Raspberry Pi 4B, boot-up may stop at the Raspberry Pi boot diagnostics screen, with a text message showing the reason for the failure.

Sample failure messages:

• “Kernel image not found”
  This would usually indicate that the “riscos.img” file is missing from the bootloader partition, but it can also point to a problem with the “config.txt” file also in that partition. For further information, see config.txt (Raspberry Pi).
• “Boot loader software is too old – upgrade boot loader”
  This indicates that you need to install newer firmware, as described here.

Boot-up stops at “Contacting DHCP server”

Aside: DHCP on RISC OS is fairly slow – it can take upwards of 20 seconds to acquire an IP address. You only need to take action if boot-up stops at that message for over 60 seconds.

The most likely reason is that you have a model of Pi which does not have a built-in Ethernet interface (Pi Zero, Pi A+ and Pi 3A+ do not). RISC OS is waiting for the interface to appear, such as plugging in an external USB-to-Ethernet adapter.

You can still boot into RISC OS by disabling networking:

1. Press ESC to reach the desktop (click Cancel on the dialogue box that appears).
2. Now click the middle mouse button on the Task Manager icon (the Raspberry Pi icon at the bottom right corner of the screen) and choose “Configure…” from the menu.
3. In the Configuration window, click on “Network” followed by “Internet”.
4. Untick the box labelled “Enable TCP/IP Protocol Suite”.
5. Close the Internet configuration window and click “Save” on the Network configuration window. You will be prompted to reboot: this should boot to the desktop with networking disabled.

Boot-up issues not mentioned here

If you encounter a boot-up issue not listed here, your first port of call should be the Community support forum.