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Using the new CM4S module with eMMC on a CM3-panel-7-basic

This article explains how to use the new Raspberry CM4S module with eMMC memory on-board on a CM3-Panel 7 basic terminal

The new CM4S module

"Based on the Raspberry Pi 4 Model B architecture, Compute Module 4S is intended for specific industrial customers migrating from Compute Module 3 or Compute Module 3+ and is not for general sale".

A Raspberry Compute IO Board is requested to transfer the OS on the eMMC memory of the CM4S module

Step-by-step procedure description

Download one of Raspberry Pi OS images available on this page:

This articles has been tested with Raspberry Pi OS Desktop and Lite version 64 bit May 3rd 2023

Insert the CM4S module on the Raspberry Pi compute module IO board v3

Place the J4 jumper on EN position the insert the USB SLAVE cable and then the POWER IN cable

Instal the usbboot utility on your PC following this instruction:

The usb utility is used to boot the Raspberry Pi CM4S with a special firmware so that it emulates an USB Mass Storage.

    $ sudo ./rpiboot
    RPIBOOT: build-date Sep 27 2023 version 20221215~105525 c4b12f85
    Waiting for BCM2835/6/7/2711...
    Loading embedded: bootcode.bin
    Sending bootcode.bin
    Successful read 4 bytes 
    Waiting for BCM2835/6/7/2711...
    Loading embedded: bootcode.bin
    Loading embedded: bootcode.bin
    Second stage boot server
    Cannot open file autoboot.txt
    Cannot open file config.txt
    Cannot open file recovery.elf
    Loading embedded: start.elf
    File read: start.elf
    Cannot open file fixup.dat
    Second stage boot server done

After that your eMMC will be visible as a normal microSD and you can save on it the Raspberry Pi OS image using the Raspberry Pi Imager software.

Inside the first partition called bootfs edit the cmdline.txt file changing:




Add these lines in config.txt file:

#Ignore the HDMI cable hotplug (to avoid the delay at startup)

# Set the debug port on GPIO32, GPIO33 pins

# Is not requested to insert this line

# Activates the I2C 1 port on GPIO44 and 45 to talk with the
# touch screen controller end camera crypto-chip

# This line is deprecated
# dtoverlay=i2c1-bcm2708,sda1_pin=44,scl1_pin=45,pin_func=6

# Use this instead


## Enable the DPI port to talk with the TFT display
hdmi_timings=800 0 40 48 88 480 0 13 3 32 0 0 0 60 0 32000000 6

and change

  • dtparam=audio=on in #dtparam=audio=on
  • dtoverlay=vc4-kms-v3d in dtoverlay=vc4-fkms-v3d
  • max_framebuffers=2 in #max_framebuffers=2

Download this file:

and save it in on the bootfs partition

Download this file:

and save it in overlays directory.

Enable the SSH server

By default the SSH server is disabled on the Rasperry pi OS standard microSD image. To enable it create an empty file called SSH with no extention on the first microSD partition. The ssh server will be enabled at first startup and you can reach the Linux command prompt via lan.

ssh pi@raspberrypi.local
Password: raspberry

Turn-off the Compute Module IO Board and remove the CM4S

Mount the CM4S module on a CM3-Panel 7 basic and turn it on

Differences between CM3+ and CM4S

CM3+ CM4
Chip Broadcom BCM2837B0 Broadcom BCM2711
CPU Cortex ARM 53 (ARMV8) Cortex ARM 72 (ARMV8)
Clock 1.2GHz 1.5GHz
Core 4 4
Bit 64 64
DIPS 3136 7080


Device tree sources


To compile it you need a Linux PC or a Raspberry Pi and a Device Tree Compiler:

sudo dtc -@ -I dts -O dtb -o /boot/overlays/goodix-7-acme.dtbo /boot/overlays/goodix-7-acme.dts 


To compile it you need a Linux PC or a Raspberry Pi and a Device Tree Compiler:

sudo dtc -I dts -O dtb -o /boot/dt-blob.bin /boot/dt-blob.dts

Sergio Tanzilli
Systems designer, webmaster of and founder of Acme Systems srl

Personal email:
Web pages: ---
Github repositories: ---
Telegram group dedicated to the Acme Systems boards:

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