EEPROM Support (Raspberry Pi 5)

The Raspberry Pi 5 stores its bootloader configuration in an SPI EEPROM on the board. WendyOS manages two EEPROM settings automatically on first boot via one-shot systemd services. This document describes what is stored, how the automatic update works, and how to inspect or change the EEPROM manually.

This page is RPi 5 specific. RPi 4 and Jetson hardware do not use this mechanism.

What is stored in the EEPROM

The RPi 5 EEPROM contains the bootloader firmware and a text-format configuration block. WendyOS cares about three keys:

Automatic EEPROM management

Two one-shot services run after multi-user.target and each execute at most once per device lifetime, guarded by flag files in /var/lib/wendyos/.

rpi5-eeprom-config.service

Source: meta-rpi-extensions/recipes-bsp/rpi-eeprom/

Script: /usr/sbin/rpi5-eeprom-update.sh

Flow:

1. Checks /var/lib/wendyos/eeprom-updated. If it exists, exits immediately.
2. Reads /proc/device-tree/model. If not RPi 5, creates the flag file and exits.
3. Calls rpi-eeprom-config to read the current EEPROM configuration.
4. If PSU_MAX_CURRENT is missing or not 3000, stages an updated EEPROM image with rpi-eeprom-update -d -f <new.bin>, creates the flag file, and reboots.
5. If already correct, creates the flag file and exits without a reboot.

rpi5-eeprom-nvme-config.service

Source: meta-rpi-extensions/recipes-bsp/rpi-eeprom/

Script: /usr/libexec/rpi5-eeprom-nvme-update.sh

Runs after rpi5-eeprom-config.service. Same flow as above, but sets PCIE_PROBE=1 and BOOT_ORDER=0xf461.

When staging the NVMe update, this service reads the live EEPROM (not the firmware binary) so that any PSU_MAX_CURRENT change from the previous service is preserved in the combined update.

Flag files

Deleting a flag file causes the corresponding service to re-run on the next boot. This lets you force a re-check after manually changing EEPROM settings.

Reading the current EEPROM configuration

SSH into the device and run:

rpi-eeprom-config

Example output:

PSU_MAX_CURRENT=3000
PCIE_PROBE=1
BOOT_ORDER=0xf461

Changing EEPROM settings manually

To change a setting, extract the current config, edit it, and stage the update:

# Extract current config to a file
rpi-eeprom-config --out /tmp/bootconf.txt

# Edit the file
nano /tmp/bootconf.txt

# Stage the update (takes effect on next reboot)
FIRMWARE=$(find /lib/firmware/raspberrypi/bootloader-2712/default -name 'pieeprom-*.bin' | head -1)
rpi-eeprom-config "${FIRMWARE}" --config /tmp/bootconf.txt --out /tmp/pieeprom-new.bin
rpi-eeprom-update -d -f /tmp/pieeprom-new.bin

# Reboot to apply
reboot

If you change PSU_MAX_CURRENT or PCIE_PROBE manually, delete the corresponding flag file before rebooting so the WendyOS service does not overwrite your change.

Firmware binary location

The EEPROM firmware images are shipped with the OS and located at:

/lib/firmware/raspberrypi/bootloader-2712/
├── default/    # Stable release firmware
├── stable/
└── latest/

The update scripts search default/, then stable/, then latest/ for a pieeprom-*.bin file.

Log files

Both services log to the journal and to flat log files:

# View service output in the journal
journalctl -u rpi5-eeprom-config.service
journalctl -u rpi5-eeprom-nvme-config.service

# Or view the flat log
cat /var/log/rpi5-eeprom-update.log
cat /var/log/rpi5-eeprom-nvme-update.log