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LG G3 Europe (lg-d855)

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Revision as of 17:06, 22 September 2022 by LittleFox (talk | contribs) (Links: Added link to service manual)
LG G3 (Europe)
LG G3 running Weston demos
LG G3 running Weston demos
Manufacturer LG
Name G3 (Europe)
Codename lg-d855
Released 2014
Hardware
Chipset Qualcomm MSM8974AC Snapdragon 801
CPU Quad-core 2.5 GHz Krait 400
GPU Adreno 330
Display 1440x2560 IPS
Storage 16/32 GB
Memory 2/3 GB
Architecture armv7
Software
Original software Android 4.4.2 on Linux 3.10
postmarketOS
Category testing
Pre-built images no
Features
Flashing
Partial
USB Networking
Works
Internal storage
No data
SD card
No data
Battery
No data
Screen
Works
Touchscreen
Works
Multimedia
3D Acceleration
No data
Audio
No data
Camera
No data
Camera Flash
No data
Connectivity
WiFi
No data
Bluetooth
No data
GPS
No data
NFC
No data
Modem
Calls
No data
SMS
No data
Mobile data
No data
Miscellaneous
FDE
No data
USB OTG
No data
HDMI/DP
No data
Sensors
Accelerometer
No data
Magnetometer
No data
Ambient Light
No data
Proximity
No data
Hall Effect
No data
Haptics
No data
Barometer
No data

Contributors

  • Nutcake

Fastboot

Before you can use fastboot on this device you need to remove LGs Download mode, which hides the standard fastboot mode. You can do this by zeroing out a partition called 'laf':

adb shell
su
dd if=/dev/block/platform/msm_sdcc.1/by-name/laf of=/sdcard/laf.img #backup LGs Download mode to the internal SD just in case
dd if=/dev/zero of=/dev/block/platform/msm_sdcc.1/by-name/laf #Overwrite laf with zeroes, enabling fastboot
exit
adb reboot bootloader #reboot directly to fastboot

More detailed instructions for this can be found here

Afterwards, you can boot into fastboot by following these steps:

1. Turn of phone completely
2. Hold Volume Up.
3. Plug in USB-cable while still holding Vol. Up until fastboot pops up

Signing the boot image

pmbootstrap will successfully flash rootfs and kernel, however the device will only boot if you use the
pmbootstrap flasher boot command, as it will otherwise show this error:

ERROR : boot certification verify
[630]_________________________________________
[640]
[640] Secure booting Error!
[640] Cause : boot certification verify
[640]
[640]_________________________________________

The message is shown for 3 seconds, then the screen blacks out and the LED will blink red and blue indefinitely.
This happens because the bootloader on the d855 variant of the LG G3 can not be unlocked and you have to trick the bootloader into thinking your boot image is legitimate.
To do this, you need to first export your boot.img-lg-d855:

mkdir -p /tmp/pmOS_export
pmbootstrap export /tmp/pmOS_export

Then we need a tool called Open_Bump, which can sign boot images for our device. (Requires Python 2. Also works for older LG devices?):

git clone https://github.com/CyboLabs/Open_Bump
cd Open_Bump
python2 open_bump.py "/tmp/pmOS_export/boot.img-lg-d855"

This will create a signed image called boot_bumped.img-lg-d855 in /tmp/pmOS_export/.
Now first flash System and kernel images using pmbootstrap and then manually flash the signed image over these:

pmbootstrap flasher flash_rootfs
pmbootstrap flasher flash_kernel
fastboot flash boot /tmp/pmOS_export/boot_bumped.img-lg-d855

Links

lk2nd

To avoid the secure boot error and get lk2nd running, download lk2nd-msm8974.img from here and remove the "SEANDROIDENFORCE" 53 45 41 4E 44 52 4F 49 44 45 4E 46 4F 52 43 45 bytes at the end of the file with a hex editor, then bump lk2nd-msm8974.img with this script and flash it to the phone with fastboot flash boot lk2nd-msm8974.img. If the bytes haven't been removed, the script will think that lk2nd has already been bumped.

Photos