Setup Raspberry Pi for flashing with flashrom Tutorial

Andreas — January 13, 2022

In this tutorial, we will go through the steps to setup a Raspberry Pi for flashing with flashrom.

Prerequisites

Things you need:

Raspberry Pi
Official 5.1V 2.5A Power Supply for Raspberry Pi.
16 GB (or more) class 10 MicroSD card for Raspberry Pi OS.
HDMI cable
Keyboard and Mouse

This tutorial assumes you're using a GNU/Linux distro for the commands outside of the Raspberry Pi and are familiar with how to use a terminal.

I'm using a Raspberry Pi 3 Model B for this tutorial but any model supported by Raspberry Pi OS will work fine.

Install and setup Raspberry Pi OS

Download Raspberry Pi OS (with Desktop is recommended) from here

Unzip Raspberry Pi OS image:

unzip IMAGE_NAME.zip

Insert the MicroSD card in a reader and check name of MicroSD card:

sudo fdisk -l

Flash the unpacked Raspberry Pi OS image to the MicroSD card:

sudo dd if=IMAGE_NAME.img of=/dev/YOURSDCARD bs=2M status=progress oflag=sync

Connect the peripherals (keyboard, mouse, HDMI, power cable), insert the MicroSD card and boot the Raspberry Pi and make sure it works.

Make sure all software is updated:

sudo apt-get update
sudo apt-get dist-upgrade
sudo reboot

Check the IP address of your Raspberry Pi:

ip addr

Write down the IP address (if using WiFi see 'inet' under 'wlan0'). It should look something like 192.168.1.11. You'll need this IP address later to be able to connect using SSH from another computer.

Next you need to change some things in the config:

sudo raspi-config

In this menu, select '3. Interface Options' and enable the following options:

SSH
SPI
I2C

Reboot the Raspberry Pi once this is done.

Try connecting to the Raspberry Pi from another computer using SSH:

ssh pi@192.168.1.11

Change '192.168.1.11' to the IP address you wrote down in earlier step. When it asks for a password, enter the password for the user 'pi'.

From here on you can disconnect all peripherals and do the rest using SSH.

Compile flashrom

Clone flashrom git repository:

git clone https://review.coreboot.org/flashrom.git

Compile flashrom:

cd flashrom
sudo make install CONFIG_ENABLE_LIBUSB0_PROGRAMMERS=no CONFIG_ENABLE_LIBUSB1_PROGRAMMERS=no CONFIG_ENABLE_LIBPCI_PROGRAMMERS=no
sudo cp /usr/local/sbin/flashrom /usr/local/bin/

Raspberry Pi GPIO pinout

Raspberry Pi 3 Model B GPIO pinout below. Raspberry Pi 4 seems to have the same layout and other models too probably. See GPIO pinout diagram for your specific Raspberry Pi to be sure.

Note: In flashing tutorials CS = GPIO08(CE0) (/dev/spidev0.0)

Raspberry Pi 3 Model B pinout

Example usage

Read from connected chip:

sudo flashrom -p linux_spi:dev=/dev/spidev0.0,spispeed=32768 -r factory_bios_01.rom -V

Read from specified chip:

sudo flashrom -p linux_spi:dev=/dev/spidev0.0,spispeed=32768 -r factory-bios-top-1.bin -c "MX25L3206E/MX25L3208E" -V

Write to connected chip:

sudo flashrom -p linux_spi:dev=/dev/spidev0.0,spispeed=32768 -w coreboot.rom -V

Write to specified chip:

sudo flashrom -p linux_spi:dev=/dev/spidev0.0,spispeed=32768 -w coreboot.rom -c "MX25L3206E/MX25L3208E" -V

Congratulations! We're done. Now you can start flashing coreboot rom's.

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