The steps I am following are as follows;

Here’s a streamlined step-by-step guide to build Halium 12.0 + LineageOS 19.x + Ubuntu Touch (Focal 20.04) for Samsung Galaxy S10 (beyond1lte) on Parrot Linux, using the exynos9820 kernel tree and vendor_samsung.

---

🧰 Prerequisites

System Setup (Parrot OS)

1. Install required packages:

   sudo apt update
   sudo apt install git-core gnupg flex bison build-essential zip curl zlib1g-dev \
     gcc-multilib g++-multilib libc6-dev-i386 lib32ncurses5-dev x11proto-core-dev \
     libx11-dev lib32z-dev ccache libgl1-mesa-dev libxml2-utils xsltproc unzip \
     fontconfig bc python-is-python3 python3-pip repo lzop
   

2. Set up git credentials:

   git config --global user.name "Your Name"
   git config --global user.email "you@example.com"
   

---

️ Create Working Directories

mkdir -p ~/halium-12.0-beyond1lte
cd ~/halium-12.0-beyond1lte

Make sure your build location is on an ext4 partition, not NTFS, or it will fail.

---

Initialize and Sync Halium + LineageOS Trees

repo init -u https://github.com/Halium/android -b halium-12.0 --depth=1
repo sync -c -j$(nproc --all) --force-sync --no-clone-bundle --no-tags

---

Clone Required Device Trees

git clone https://github.com/LineageOS/android_device_samsung_beyond1lte -b lineage-19.1 device/samsung/beyond1lte
git clone https://github.com/LineageOS/android_device_samsung_exynos9820-common.git -b lineage-19.1 device/samsung/exynos9820-common
git clone https://github.com/TheMuppets/proprietary_vendor_samsung -b lineage-19.1 vendor/samsung
git clone https://github.com/LineageOS/android_kernel_samsung_exynos9820 -b lineage-19.1 kernel/samsung/exynos9820

---

️ Apply Halium Patches

Use Halium’s helper script:

bash halium/devices/setup-device device/samsung/beyond1lte

Or apply relevant patches manually from:
https://github.com/Halium/halium-devices/

Make sure to patch:

• init
• system/core
• build
• system/sepolicy

---

️ Prepare Ubuntu Touch Rootfs

1. Install ubuntu-device-flash and pmbootstrap if needed.

2. Download rootfs:

   mkdir -p ubuntu-touch
   cd ubuntu-touch
   wget https://cdimage.ubports.com/ubuntu-touch/edge/channel/halium/ubuntu-touch-android12-arm64-rootfs.tar.gz
   

---

🧱 Build Halium System

source build/envsetup.sh
lunch lineage_beyond1lte-eng
mka halium-boot
mka systemimage

Output images will be in out/target/product/beyond1lte/

---

Flash the Device (Example)

fastboot flash boot out/target/product/beyond1lte/halium-boot.img
fastboot flash system out/target/product/beyond1lte/system.img

Then push the rootfs and resize:

adb shell
mkdir /data/rootfs
exit

adb push ubuntu-touch-android12-arm64-rootfs.tar.gz /data/
adb shell
cd /data
tar -xzf ubuntu-touch-android12-arm64-rootfs.tar.gz

---

Final Steps

• Set up libhybris compatibility.
• Adjust fstab, init.rc, and udev.
• Test Halium Boot → If it gets to root shell, you're almost there.
• Deploy Ubuntu Touch via ubports-installer or halium-install.