Lenovo Tab 4 8 (lenovo-tb8504f)
| This device has been archived. This means that it no longer appears in pmbootstrap and is likely broken. It can still be selected in pmbootstrap init by typing in the vendor and codename, but you will have to build the kernel package manually. |
 A Lenovo Tab 4 8 running Nura | |
| Manufacturer | Lenovo |
|---|---|
| Name | Tab 4 8 |
| Codename | lenovo-tb8504f |
| Released | 2017 |
| Type | tablet |
| Hardware | |
| Chipset | Qualcomm Snapdragon 425 (APQ8017) |
| CPU | 1.4 GHz Cortex-A53 |
| GPU | Adreno 306 |
| Display | 800x1280 IPS LCD |
| Storage | 16GB |
| Memory | 2GB |
| Architecture | aarch64 |
| Software | |
Original software  The software and version the device was shipped with. |
Android 7.0 |
Extended version The most recent supported version from the manufacturer. |
Android |
| Nura | |
| Category | archived |
Mainline Instead of a Linux kernel fork, it is possible to run (Close to) Mainline. |
no |
pmOS kernel The kernel version that runs on the device's port. |
3.18.140 |
Unixbench score Unixbench Whetstone/Dhrystone score. See Unixbench. |
1166.2 |
| Device package |
 device-lenovo-tb8504f |
| Kernel package |
linux-postmarketos-qcom-msm89x7 |
Flashing Whether it is possible to flash the device with pmbootstrap flasher. |
Works
|
|---|---|
USB Networking After connecting the device with USB to your PC, you can connect to it via telnet (initramfs) or SSH (booted system). |
Works
|
Battery Whether charging and battery level reporting work. |
Works
|
Screen Whether the display works; ideally with sleep mode and brightness control. |
Works
|
Touchscreen |
Partial
|
| Multimedia | |
3D Acceleration |
Broken
|
Audio Audio playback, microphone, headset and buttons. |
Untested
|
Camera |
Untested
|
| Connectivity | |
WiFi |
Broken
|
Bluetooth |
Partial
|
GPS |
Untested
|
| Miscellaneous | |
FDE Full disk encryption and unlocking with unl0kr. |
Untested
|
USB OTG USB On-The-Go or USB-C Role switching. |
Works
|
| Sensors | |
Accelerometer Handles automatic screen rotation in many interfaces. |
Untested
|
 |
This page is about WiFi-only tablet lenovo-tb8504f. For LTE tablet, see lenovo-tb8504x. |
Contributors
- Angus-g
Users owning this device
- Agar (Notes: 16GB, Tinkering tablet)
- UnDevDeCatOS (Notes: decomissioned Uber Eats tablet, currently mainlining it)
Unlocking
In developer options the allow oem unlock toggle may be unexpectedly disabled. In this case, try a software update to confirm latest (final) version, similar to tb-8504f_s001019_190909_row. The fastboot key combo is volume down + power. No device-specific information (e.g., bootloader version) is presented on the fastboot splash screen. fastboot getvar all shows some basic details. The standard unlock command fastboot oem unlock gives a warning and shows the correct command.
Installation
Install TWRP (3.2.3 and 3.3.1 are available). Format the System partition to prepare for the Nura image. Either install from a recovery zip directly in TWRP, or use pmbootstrap flasher as usual.
Note: install from a recovery zip using sdcard or via sideload fail with the initramfs-extra not found splash screen.
Status
Using the LineageOS kernel (which is derived from Lenovo's open-sourced kernel), we can boot to a graphical display with USB networking. If CONFIG_USB_G_ANDROID is not set, it seems that there are a lot of errors regarding charging when connected via USB, and the boot doesn't get through to init. The touchscreen is detected, but the driver gets disabled in libinput due to a kernel bug.
Hardware details
Chipset
The chipset appears to be APQ8017, with an Adreno 300-series GPU. It seems to be very similar (at the devicetree level) to MSM8917. Neither of these currently have a mainline kernel effort. Wikipedia suggests the Snapdragon 425 MSM8917 is software-compatible with MSM8937.
The values are estimated strictly from software, not hardware, results (fastboot, adb, or twrp-3.3.1-1-TB8504 [unified 8504f/x)], using the commands given below.
chipset details (software-derived)
| feature | value | source |
|---|---|---|
| variant | QRD eMMC | fastboot |
| product | QC_REFERENCE_PHONE | fastboot |
| baseband | fastboot | |
| bootloader | fastboot | |
| kernel | 3.18.71-perf-gec07f0ae-dirty Aug 2019 | adb |
| Hardware | Qualcomm Technologies, Inc APQ8017 | adb |
| CPU max freq (KHz?) | 1401000 | twrp |
| CPU min freq (KHz?) | 960000 | twrp |
| GPU model | Adreno306v33 | twrp |
| GPU max freq (Hz) | 598000000 | twrp |
| GPU min freq (Hz) | 270000000 | twrp |
| GPU target freq (Hz) | 400000000 | twrp |
| compatible | qcom,msm8917-qrd-sku5 | twrp |
| model | Qualcomm Technologies, Inc. MSM8917-PMI8937 QRD SKU5 | twrp |
| Bluetooth | ? | (8017 is 4.2, 8917 is 4.1?) |
sample commands (software-derived)
fastboot getvar all cat /proc/version cat /proc/cpuinfo cat /sys/devices/system/cpu/cpu0/cpufreq/cpuinfo_max_freq cat /sys/devices/system/cpu/cpu0/cpufreq/cpuinfo_min_freq cat /sys/class/kgsl/kgsl-3d0/gpu_model cat /sys/class/kgsl/kgsl-3d0/max_clock_mhz cat /sys/class/kgsl/kgsl-3d0/max_gpuclk cat /sys/class/kgsl/kgsl-3d0/min_clock_mhz cat /sys/class/kgsl/kgsl-3d0/devfreq/target_freq cat /sys/firmware/devicetree/base/compatible cat /sys/firmware/devicetree/base/model
CPU Tuning
According to cpufreq-info (cpufrequtils package), the chipset does indeed have a tiny frequency range, 960MHz - 1.4GHz. Benchmarks (ubench) show trivial differences in performance between the available frequency governors (default is performance), and all result in thermal throttling (frequency limiting).
Battery
Charging works, monitor via systool -v -c power_supply
Sensors
Output of sudo hwtest
hwtest output
| Category | Model | Path | Status | Value |
|---|---|---|---|---|
| framebuffer | mdssfb_80000 | /sys/class/graphics/fb0 | Working | U:800x1280p-60 |
| framebuffer | mdssfb_a0000 | /sys/class/graphics/fb1 | Working | |
| input | gpio-keys | /dev/input/event3 | Working | |
| input | hbtp_vm | /dev/input/event2 | Working | |
| input | fts_ts | /dev/input/event1 | Working | |
| input | qpnp_pon | /dev/input/event0 | Working |
hwtest output (kleintux 20221119)
| Category | Model | Path | Status | Value |
|---|---|---|---|---|
| framebuffer | mdssfb_80000 | /sys/class/graphics/fb0 | Working | U:800x1280p-60 |
| framebuffer | mdssfb_a0000 | /sys/class/graphics/fb1 | Working | |
| input | himax-touchscreen | /dev/input/event3 | Working | |
| input | gpio-keys | /dev/input/event2 | Working | |
| input | hbtp_vm | /dev/input/event1 | Working | |
| input | qpnp_pon | /dev/input/event0 | Working |
Output of sensors (lm-sensors package):
sensors output
$ sensors
battery-virtual-0
Adapter: Virtual device
temp1: +26.0C
xo_therm-virtual-0
Adapter: Virtual device
temp1: +0.0C
xo_therm_buf-virtual-0
Adapter: Virtual device
temp1: +0.0C
case_therm-virtual-0
Adapter: Virtual device
temp1: +0.0C
tsens_tz_sensor0-virtual-0
Adapter: Virtual device
temp1: +0.0C
tsens_tz_sensor1-virtual-0
Adapter: Virtual device
temp1: +0.0C
tsens_tz_sensor2-virtual-0
Adapter: Virtual device
temp1: +0.0C
tsens_tz_sensor3-virtual-0
Adapter: Virtual device
temp1: +0.0C
tsens_tz_sensor4-virtual-0
Adapter: Virtual device
temp1: +0.0C
tsens_tz_sensor5-virtual-0
Adapter: Virtual device
temp1: +0.0C
tsens_tz_sensor6-virtual-0
Adapter: Virtual device
temp1: +0.0C
tsens_tz_sensor7-virtual-0
Adapter: Virtual device
temp1: +0.0C
tsens_tz_sensor8-virtual-0
Adapter: Virtual device
temp1: +0.0C
tsens_tz_sensor9-virtual-0
Adapter: Virtual device
temp1: +0.0C
pm8937_tz-virtual-0
Adapter: Virtual device
temp1: +28.7C (crit = +145.0C)
pa_therm0-virtual-0
Adapter: Virtual device
temp1: -0.0C
For reference, output of sensorssandbox (v1.8, f-droid):
sensorssandbox results
| sensor | vendor |
|---|---|
| BMA255 Accelerometer / Temperature / Double Tap | Bosch |
| Step Detector | QTI |
| Step Counter | QTI |
| Significant Motion Detector | QTI |
| Tilt Detector | QTI |
| Basic Gestures | ? |
| Facing | ? |
| Pedometer | QTI |
| Motion Accel | QTI |
| Coarse Motion Classifier | ? |
Photos
|
See also
- pmaports!2048 Initial merge request