Project RETR0 | NVIDIA SHIELD K1 Android 8.1 Guide

PROJECT RETR0 • ADVANCED DEVICE GUIDE

NVIDIA SHIELD Tablet K1Android 8.1 Upgrade

A detailed reconstruction of the successful LineageOS 15.1 / Android 8.1 installation, covering TWRP, off-device backup, Google Play, NVIDIA Tegra verification, storage repair and preservation.

DEVICESHIELD Tablet K1

CODENAMEshieldtablet

SOCNVIDIA Tegra K1

ANDROID8.1.0 / API 27

ROMLineageOS 15.1

Modification warning: unlocking, wiping and flashing can erase data or make the tablet unbootable. Verify the target device and preserve a working backup first.

STEP 1 OF 14

Assets & Preparation

PROJECT RETR0 • COMPLETE ASSET PACK

SHIELD K1 Android 8.1 Assets

Download the supporting files used with this guide. The webpage remains the installation procedure.

↓ Download SHIELD K1 Asset Pack

File	Purpose	Use
`lineage-15.1-20211113-UNOFFICIAL-shieldtablet.zip`	LineageOS 15.1 / Android 8.1 ROM	Required
`open_gapps-arm-8.1-pico-20220215.zip`	Google Play and Google services	Required for Google apps
`twrp-3.7.0_9-0-shieldtablet.img`	TWRP recovery	Required for this workflow
`platform-tools-latest-windows.zip`	ADB / Fastboot	Required
`SHIELD_Family_WHQL_USB_driver_201801.zip`	NVIDIA Windows USB driver	Recommended
`usb_driver_r13-windows.zip`	Google USB driver	Fallback

Before modifying the tablet: charge it, use a reliable USB cable, preserve important data, and verify that every image is intended for shieldtablet.

STEP 2 OF 14

Verify ADB & Device

Enable Developer options and USB debugging. Connect the tablet, approve the PC, and confirm that ADB sees it.

adb devices adb shell getprop ro.product.device adb shell getprop ro.build.version.release

The target must be the NVIDIA SHIELD Tablet / K1 family. Do not flash files intended for SHIELD TV or another Tegra device.

STEP 3 OF 14

Bootloader & Unlock

Enter the bootloader and verify Fastboot communication:

adb reboot bootloader
fastboot devices

If Fastboot returns nothing, inspect Windows Device Manager while the tablet is in bootloader mode and install/assign the NVIDIA SHIELD USB driver.

fastboot oem unlock

Unlocking can erase user data. Read the confirmation shown on the tablet and proceed only when your important files are protected.

STEP 4 OF 14

Install TWRP Recovery

From the directory containing the recovery image:

fastboot flash recovery twrp-3.7.0_9-0-shieldtablet.img

Verify the filename and device target before pressing Enter. Flashing the wrong recovery image can prevent recovery from booting.

STEP 5 OF 14

Create a Stock Backup

Boot TWRP and create a recovery backup before replacing the stock installation. The successful documented backup contained System, Data and Boot.

Files observed in the backup

system.ext4.win system.ext4.win.sha2 data.ext4.win data.ext4.win.sha2 boot.emmc.win boot.emmc.win.sha2

Locate the backup rather than assuming its path:

adb shell "find /sdcard -type f -name '*.win*' 2>/dev/null"

Then copy the generated backup folder to the PC:

adb pull "/sdcard/InternalStorage/TWRP/BACKUPS/YOUR_DEVICE/YOUR_BACKUP" "C:\SHIELD_K1_Stock_Backup"

Confirm the backup exists on the PC before performing the ROM wipe.

STEP 6 OF 14

Transfer ROM & Google Apps

Copy the two flashable ZIP files to storage accessible from TWRP.

adb push "lineage-15.1-20211113-UNOFFICIAL-shieldtablet.zip" "/sdcard/InternalStorage/"
adb push "open_gapps-arm-8.1-pico-20220215.zip" "/sdcard/InternalStorage/"

Sizes recorded during the successful installation

LineageOS: 396,817,580 bytes (~378 MiB) Open GApps: 191,618,543 bytes (~183 MiB)

STEP 7 OF 14

Wipe & Flash Android 8.1

In TWRP, verify that the ROM, GApps and off-device backup are available. Perform the clean-ROM wipe needed for the installation without deleting the only copy of your packages.

1Install lineage-15.1-20211113-UNOFFICIAL-shieldtablet.zip2Install open_gapps-arm-8.1-pico-20220215.zip3Reboot System

ROM first, GApps second. If you want Google services, install GApps immediately after the ROM rather than deliberately completing Android’s first boot between the two.

STEP 8 OF 14

Verify the Android 8.1 Installation

After the first boot and setup, re-enable USB debugging and inspect the new system:

adb shell getprop ro.build.version.release
adb shell getprop ro.build.version.sdk
adb shell getprop ro.lineage.display.version
adb shell dumpsys SurfaceFlinger | findstr /i "GLES"

Verified result

Android: 8.1.0 API: 27 LineageOS: 15.1-20211113-UNOFFICIAL-shieldtablet GLES: NVIDIA Corporation, NVIDIA Tegra, OpenGL ES 3.2 NVIDIA 361.00

STEP 9 OF 14

Verify NVIDIA Features & Services

The custom ROM retained important NVIDIA vendor components. Inspect them with:

adb shell pm list packages | findstr /i "nvidia tegra shield"
adb shell pm list features | findstr /i "nvidia shield"
adb shell getprop persist.sys.NV_POWER_MODE
adb shell settings get system nv_power_mode
adb shell settings get system nv_default_power_mode
adb shell dumpsys activity services com.nvidia.NvCPLSvc

Packages found

com.nvidia.shieldtech.hooks com.nvidia.tegrazone3 com.nvidia.NvCPLSvc

The installation also exposed NVIDIA SHIELD, DirectStylus, OpenGL4 and NVSI feature declarations. NvCPLSvc was active, and power-mode value 1 was observed.

STEP 10 OF 14

Storage / Play Store Repair

During the documented installation, Play Store repeatedly opened Free up space even though internal storage had about 8.7 GB free. The actual problem was a stale adopted-storage configuration: emulated internal storage was not mounted correctly.

adb shell sm list-disks
adb shell sm list-volumes all
adb shell sm get-primary-storage-uuid
adb shell mount
adb shell df -h

The successful repair returned the SD card to portable/public storage:

adb shell sm forget all
adb shell sm partition YOUR_DISK_ID public
adb reboot

sm partition erases the selected SD card. Run sm list-disks and use the disk ID reported by your own tablet. Back up the card first.

Working state after repair

Internal emulated storage: mounted Primary storage UUID: null SD card: public / portable storage Play Store update: successful

STEP 11 OF 14

TegraZone Update & Inspection

After the storage repair, the NVIDIA/TegraZone application updated successfully. Inspect the installed package with:

adb shell dumpsys package com.nvidia.tegrazone3 | findstr /i "versionName versionCode codePath"

Updated application observed

versionCode=559621565 versionName=6.37.38533849 codePath=/data/app/...

The older vendor copy remains under /system/vendor/app/TegraZone/ as the system base package.

STEP 12 OF 14

Preserve NVIDIA Vendor APKs

Optional: archive the NVIDIA applications from the working installation before further experimentation.

mkdir "C:\SHIELD_NVIDIA_APKS" adb pull "/system/vendor/app/NvCPLSvc/NvCPLSvc.apk" "C:\SHIELD_NVIDIA_APKS\NvCPLSvc.apk" adb pull "/system/vendor/app/NvShieldTech/NvShieldTech.apk" "C:\SHIELD_NVIDIA_APKS\NvShieldTech.apk" adb pull "/system/vendor/app/TegraZone/TegraZone.apk" "C:\SHIELD_NVIDIA_APKS\TegraZone.apk"

STEP 13 OF 14

SHA-256 Asset Manifest

These are the hashes recorded for the exact files in the documented asset collection:

442c703a70f72dbc477b8572c8fad2f2ad6489f480b5531e89092355206499eeLineageOS ZIP 034c91278ab3c7f9af15fb8a77633dabaf490105cc42ad7d5be616220202f2d4Open GApps ZIP fa08842fe2cb6631b6d65650812252ee8140fcf7b1450bd195d661b54fc0b271TWRP image fc4ab66ec27294f51af912df2afe8d8083fcc11a0f8d58cfb1423cc4a39cf292NVIDIA USB driver 4fe305812db074cea32903a489d061eb4454cbc90a49e8fea677f4b7af764918Platform Tools ZIP 360b01d3dfb6c41621a3a64ae570dfac2c9a40cca1b5a1f136ae90d02f5e9e0bGoogle USB driver r13

A matching checksum confirms byte-for-byte identity with the archived file. It does not independently establish provenance or compatibility.

STEP 14 OF 14

Troubleshooting & Project RETR0 Support

ADB shows unauthorized

Unlock the tablet, accept the USB-debugging authorization prompt, then run adb devices again.

Fastboot cannot see the tablet

Check Windows Device Manager while the tablet is in bootloader mode and install/assign the SHIELD USB/Fastboot driver.

Play Store says “Free up space”

Check sm list-volumes all, the primary-storage UUID and /storage/emulated. Do not assume the message means the physical flash storage is actually full.

ADB gets Permission denied under /sys

Many kernel interfaces are intentionally inaccessible to an ordinary ADB shell. That result alone does not mean the Tegra driver stack is broken.

PROJECT RETR0 • COMMUNITY SUPPORT

Need help?

Join the Project RETR0 Discord and include the guide step, exact error, device state, and relevant ADB/Fastboot output.

Join Project RETR0 Discord

Documented final state: SHIELD Tablet K1 running Android 8.1 / API 27 with LineageOS 15.1, Google Play, NVIDIA Tegra OpenGL ES 3.2 driver stack, NVIDIA vendor services, functional internal emulated storage and portable SD storage.