Motorola Droid 4

Motorola Droid 4
Manufacturer	Motorola
Codename	Maserati
Dimensions	127x67.3x12.7mm
Release Date	2012-02-10
Category	Supported
Specifications
SoC	TI OMAP4430
DRAM	1024MB DDR2
Hardware Features
LCD	960x540 4"
Video	PowerVR SGX540
Storage	16GB flash
Sensors	AK8975 compass, LIS3DH accelerometer, ISL29030 proximity and illuminance, TMP105 temperature sensor
Software Features
Kernel	5.11.0
Serial	Yes, special cable
Charging	Yes
USB Slave	Yes
USB Host	Yes
Touchscreen	Yes
Keyboard	Yes
Screen	Yes
HDMI-out	Yes
3D acceleration	Yes [1] (closed)
Vibration motor	Yes
Audio	Yes
Phone calls	WIP
SMS	Yes, no UI
Wifi	Yes
2G/3G data	Yes
Bluetooth	Yes, see notes
FM transmitter	No, but apparently exists, needs serdev kernel modules/drivers
Accelerometer	Yes
Compass	Yes, no integration
Proximity Sensor	Yes
Ambient Light Sensor	Yes
GPS	Yes
A-GPS	No
Front Camera	No
Back Camera(s)	No
Idle Power Consumption	120mW

Installation

Hardware requirements:

• Droid4 with fully charged battery
• MicroUSB cable
• MicroSD card

Software requirements:

• Host Linux or Windows system
• Android Tools: fastboot
• Flashing tools:
  • XZ Utils and coreutils for Linux
  • Etcher[2] for Windows

Download from https://maedevu.maemo.org/images/droid4/

1. VRZ_XT894_9.8.2O-72_VZW-18-8_CFC.xml.zip
2. flash-droid-4-fw.sh
3. Latest maemo-leste-1.0-armhf-droid4-*.img.xz

Download from https://github.com/tmlind/droid4-kexecboot.git

1. utags-mmcblk1p13.bin
2. droid4-kexecboot.img

Check what kernel version your Android OS runs. For this go to Settings -> About phone. Slide to the bottom, where you can see "Kernel version". If you have at least 3.0.8, you may skip "Updating Android" step below.

Installation:

1. Create a working directory with above mentioned files in it
2. unzip VRZ_XT894_9.8.2O-72_VZW-18-8_CFC.xml.zip
3. Power off Droid4 and connect it to the host machine with MicroUSB cable
4. Start the device in fastboot mode. For this press power button and bottom volume key simultaneously and release them after a second.

Updating Android

This will reinstall the Android OS on your device, deleting all user data. Do a backup, if you want to save something. When everything is ready, go to the working directory mentioned above and run:

pushd VRZ_XT894_9.8.2O-72_VZW-18-8_CFC.xml
sudo bash ../flash-droid-4-fw.sh
popd

Setting up kexecboot

Now, assuming you are in the working directory, install kexecboot:

sudo fastboot flash mbm VRZ_XT894_9.8.2O-72_VZW-18-8_CFC.xml/allow-mbmloader-flashing-mbm.bin
sudo fastboot reboot-bootloader
sudo fastboot flash bpsw droid4-kexecboot.img
sudo fastboot flash utags utags-mmcblk1p13.bin
sudo fastboot reboot

If you did "Updating Android" the device should run the firstboot steps. If you didn't, the device should reboot and show kexecboot menu for a few seconds before it boots to Android.

Install Maemo Leste to the sdcard

Now, flash the Maemo Leste image to your sdcard:

On Linux:

xzcat maemo-leste-1.0-armhf-droid4-20190227.img.xz | sudo dd status=progress bs=1M of=/dev/MICROSDCARD-DEVICE
sync

On Windows: Use Etcher

Wait for sync to complete and insert MicroSD card into Droid4. Reboot the device and select Maemo Leste from the kexecboot menu.

You should now see Maemo Leste booting up, and it will show you hildon-desktop after a minute.

Updating

Normally you can just apt update && apt dist-upgrade to update to the latest version. If for some reason this fails:

• Poweroff device, grab the SD card
• Backup any important files
• Grab the latest image from https://phoenix.maemo.org/view/Images/
• Write it as before : xzcat maemo-leste-1.0-armhf-droid4-20190227.img.xz | sudo dd status=progress bs=1M of=/dev/MICROSDCARD-DEVICE

Notes

The battery in Droid4 is not easily removable. If you got the device stuck, use this combo: power button + bottom volume key. You should hold them for about 7 seconds. Droid4 will then reboot.

If Maemo is still running, you can also hold just the power button for ~10 seconds, and the device will run poweroff.

Some users reported that Bluetooth kernel module interfere badly with the WiFi driver on their devices. Blacklisting the module may help if you have such problems:

echo "blacklist hci_uart" >> /etc/modprobe.d/blacklist.conf

Also see Motorola_Droid_4/Modem Motorola_Droid_4/PowerVR

Also see: http://elektranox.org/droid4/ and http://muru.com/linux/d4/

Serial Cable

As explained at http://muru.com/linux/d4 , the Droid 4 exposes a serial console on the USB port. You can construct the required cable easily by following the instructions there. If you have old Nokia CA-42 or DKU-5 cables, then you can use them with the Droid 4, using instructions at https://jethomson.wordpress.com/2010/02/21/diy-usb-to-serial-cable-for-3usd/

While using the serial cable, if you lose the connection, the following may help:

18:43 < tmlind> sicelo: hmm the uart debug cable multiplexing still has issues, if the uart disappears during boot it should come back with 
                the console login propt later
18:45 < tmlind> try plugging in a pc usb cable then back to uart cable in case that might help

Bluetooth

Needs firmware - install latest firmware-ti-connectivity - See also https://github.com/maemo-leste/bugtracker/issues/290. Due to interference with WiFi, load driver manually, AFTER wifi module loaded

Stuff to try

Blinkenlights

Adding this in rc.local above the exit 0 gets you some blinkenlights to watschen und relaxen.

echo cpu > /sys/class/leds/lm3532::kbd_backlight/trigger # gets you a cpu activity monitor on the keyboard backlight
echo mmc0 > /sys/class/leds/shift-key-light/trigger      # gets you a 'hdd led' of the SD card on the capslock light

Wifi

The WL1285C Wifi chip in the droid 4 has no onboard nvmem to save its calibration parameters or its MAC address. Instead it gets these parameters from a configuration file provided by the kernel. By default a generic file is provided but for optimal range and a correct persistent MAC address a calibration procedure must be performed.

Install necessary tools:

apt-get install ti-utils-wilink6 droid4-wlanconfig

Run calibration:

sudo maserati-calibrate

Phone Call

Make sure there is a SIM in the phone.

Run this:

Read modem output:

cat /dev/motmdm1 &

Online modem:

printf "AT+CFUN=1\r" > /dev/motmdm1

Connect to network:

printf "AT+COPS=1\r" > /dev/motmdm1

Print connected network:

printf "AT+COPS?\r" > /dev/motmdm1

Turn off signal reporting:

# printf "AT+SCRN=0\r" > /dev/motmdm1

Dial a number:

printf "ATD+1234567890\r" > /dev/motmdm1

Hang up:

printf "ATH\r" > /dev/motmdm1

Answer incoming call:

printf "ATA\r" > /dev/motmdm1

Audio wise, in a pulsaudio of you choice switch to the make a phone call profile, and set the output device as desired.

3G Internet

Using qmicli:

1. qmicli -d /dev/cdc-wdm0 --wds-follow-network --wds-start-network=apn=internet.t-mobile.cz
2. route del default
3. sudo ifconfig wwan0 up
4. dhclient wwan0

Alternatively if updated to devel icd2 and the maemo gui should allow 3g data connection, if the sim is unlocked and the relevant packages are installed.

GPS

modprobe gnss-motmdm and point gpsd to use /dev/gnss0

22:30 < tmlind> hmm there's a probably kernel gnss bug for gsp access fyi, you can currently only open one connection before you have to restart gpsd :)

Can try to

mkfifo /tmp/gps
cat /dev/gnss0 > /tmp/gps
Then point gpsd to use /tmp/gps

USSD

22:45 < tmlind> fyi, here's how to send USSD to query balance for example: printf "AT+CUSD=1,#999#,0\r" > /dev/motmdm1
22:47 < tmlind> fyi, for parsing incoming USSD, this web interface works if set to utf-8: 
                https://www.mobilefish.com/services/latin_utf_base64_to_hex/latin_utf_base64_to_hex.php#text_hex_output

HDMI

Move output to external 1080p monitor. Disabling DSI-1 output gets xorg pointer displayed on HDMI, for use with a mouse or barrier.

xrandr --output HDMI-1 --mode 1920x1080 --output DSI-1 --off

Return to internal touchscreen display.

xrandr --output DSI-1 --auto --rotate right --output HDMI-1 --off

Keyboard / Mouse sharing with PC

To use droid4 while working at desktop it can be convenient to share mouse and keyboard of the host pc with droid4.

[https://github.com/debauchee/barrier Barrier software-KVM switch]

Developers and testers may wish to disable the googley bits before compiling.

BT Audio headset

• sudo apt install pulseaudio-module-bluetooth blueman bluez
• sudo modprobe hci_uart
• pactl load-module module-bluetooth-discover
• blueman
• pair & trust your device, connect audiosink

Quality seems a bit better in 'offline mode'.

Gallery

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Old status overview

Feature	Leste supported	Notes
Kernel version	5.9.0	Mainline + some patches not yet in mainline - see https://github.com/maemo-leste/droid4-linux
Serial	Yes	On MicroUSB port, requires special cable
Charging	Yes
Wireless	Yes
Ethernet	N/A
Micro USB	Yes	OTG and USB network
Keyboard	Yes	Slightly modified keyboard layout, see https://www.spinics.net/lists/linux-omap/msg135137.html (TLDR; Shift key produces CTRL, SYM produces ALT, and Caps lock produces SHIFT)
Screen	Yes
3D Acceleration	Yes	PowerVR SGX540 (closed driver) - https://github.com/maemo-leste/pvr-omap4/
Touchscreen	Yes	Capacitive
Audio	Yes	Implemented with Pulseaudio and UCM files
2G/3G data	Yes	Works with ofono, no UI yet - see https://github.com/maemo-leste/connui-cellular/
4G data	No	Needs kernel work
SMS	Yes	Works with ofono. Needs Leste UI
Phone calls	Yes	Works with ofono (good call quality, too), needs Leste UI
Bluetooth	Yes	Needs firmware - install latest firmware-ti-connectivity - See also https://github.com/maemo-leste/bugtracker/issues/290. Due to interference with WiFi, load driver manually, AFTER wifi module loaded
FM Transmitter	No	Apparently exists, and will need serdev kernel modules/drivers
FM Receiver	Not yet
Accelerometer	Yes	Available in /sys, and as input device via iio-uinput
Compass	Yes	Available in /sys (after loading ak8975 module. No Leste integration applications using it yet)
Gyro	N/A
Proximity sensor	Yes
Ambient Light Sensor	Yes
Vibration Motor	Yes
HDMI-out	Yes	No UI integration
TV-out	N/A
GPS	Yes	Works with gpsd but is not integrated yet, see GPS
Infrared	N/A	Missing in hardware
Camera	No	See https://elektranox.org/2018/02/0025-droid-camera/
Idle power consumption	~120mW	Needs sim inserted