Motorola Droid 4

Motorola Droid 4
Manufacturer	Motorola
Codename	Maserati XT894
Dimensions	127x67.3x12.7mm
Release Date	2012-02-10
Category	Supported
Specifications
SoC	TI OMAP4430 Cortex-A9 Armv7‑A
DRAM	1024MB DDR2
Hardware Features
LCD	960x540 4"
Video	PowerVR SGX540
Storage	16GB flash
Sensors	AK8975 compass, LIS3DH accelerometer, TMP105 temperature, ISL29030 proximity and illuminance
Software Features
Kernel	5.18.x
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	Yes
SMS	Yes
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/

The keyboard layout is extended to provide more standard keys.

maemo-leste droid4 keyboard

Key mapping can be tested with the 'xev' program.

It may be necessary to run the follow commands as root in order to get the OK key to function correctly (see here):

udevadm hwdb --update
udevadm trigger

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. So you should do:

sudo apt install firmware-ti-connectivity
sudo modprobe hci_uart
sudo hciconfig hci0 up
sudo hcitool lescan

Stuff to try

Using a battery without temperature sensor

Modprobe the pmic driver as follows:

cpcap-battery ignore_temperature_probe=1

Flashing the boot logo

More info: https://github.com/xsetiadi/droid4-kexecboot/blob/master/LOGO

15:04 < tmlind> Wizzup: i think the logo on droid4 can be flashed with fastboot flash logo logo.bin or something, can also be just written to logo partition from m-l
[snip]
09:24 < xsetiadi> https://github.com/xsetiadi/droid4-kexecboot/blob/master/logo.bin
09:25 < xsetiadi> becarefull, you can bootloop droid4 if you wrong flash partition
09:26 < xsetiadi> like i do last year
09:26 < xsetiadi> instead of flashing using command: fastboot flash logo.bin logo.bin i just flash it with command: fastboot flash logo logo.bin

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

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

If one wants to mirror the screen on HDMI, this can be done like so, for landscape:

xrandr --newmode "960x540_60.00"   40.75  960 992 1088 1216  540 543 548 562 -hsync +vsync
xrandr --addmode HDMI-1 "960x540_60.00"
xrandr --output HDMI-1 --mode "960x540_60.00" --same-as DSI-1

For rotation, something like this might or might not work:

xrandr --newmode "960x540_60.00ROT" 43.00  544 576 632 720  960 963 973 996 -hsync +vsync
xrandr --addmode HDMI-1 "960x540_60.00ROT"
xrandr --output HDMI-1 --mode "960x540_60.00" --same-as DSI-1 --rotate right

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-manager

Pair & trust your device in blueman, connect audiosink. You can close blueman now. The quality seems a bit better in 'offline mode'.

Torch

The Droid 4 has a TI LM3559 flash torch controller. This provides flash functionality when taking pictures, usage as a torch, and provides privacy indication (in this mode, the LED flashes in a fast heartbeat pattern). A driver for it exists in mainline, but it requires some DTS work, since it is tied to a camera device.

If you want to use it in the meantime, direct i2c access can be used as follows (since this is direct access, be careful about each of the commands below):

##Install the prerequisites
$ sudo apt install i2c-tools

## Turn LED on in torch mode
$ sudo i2cset -y 2 0x53 0x10 0x1a

## Turn LED on in privacy indication mode
$ sudo i2cset -y 2 0x53 0x10 0x19

## Turn LED off (in any mode)
$ sudo i2cset -y 2 0x53 0x10 0x18

## Use LED for doing a hella bright flash for some time once and then turn off
$ sudo i2cset -y 2 0x53 0x10 0x1b

Using a configured Leste sdcard in a different Droid4

A configured Droid4 Leste installation is unique to the device that it was calibrated on. Particularly the wlan firmware calibration will be incorrect if an existing Leste installation is transferred to a different device.

The wifi calibration script requires a system set to stock settings to calibrate-from. It cannot just be re-run on an already calibrated system.

To recalibrate the wifi firmware on a different Droid4, you must reset the FEM parameters to stock settings on the new device, then recalibrate. If you can get the device online (usb networking or moving close to the WLAN AP) this can be done with.

apt reinstall firmware-ti-connectivity 

If not, you can download the firmware-ti-connectivity_[version]_all.deb on another Leste device

apt download firmware-ti-connectivity

Then copy the .deb to your new device and install that (as root) with

dpkg -i firmware-ti-connectivity_[version]_all.deb 

Then (as root) re-calibrate the wifi chip by running

/usr/bin/maserati-calibrate

Then reboot.

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