Copyright belongs to the author. If reposting, please indicate the source of the article: https://cyrus-studio.github.io/blog/

Source Code Download

• • LineageOS Official Website: https://lineageos.org/
• • LineageOS Source Code GitHub: https://github.com/LineageOS/android
• • LineageOS Source Code Domestic Mirror: https://mirrors.tuna.tsinghua.edu.cn/help/lineageOS/

The source code requires approximately 150GB of hard disk space, and the compiled output will be around 300GB.

1. Configure Git

git config --global user.email "[email protected]"
git config --global user.name "Your Name"

2. Install Repo

mkdir ~/bin
PATH=~/bin:$PATH
curl https://storage.googleapis.com/git-repo-downloads/repo > ~/bin/repo
chmod a+x ~/bin/repo

3. Install Git LFS

sudo apt install git-lfs
git lfs install

4. Install Android SDK Platform-Tools

To configure the Android SDK Platform-Tools^[1] on Linux, follow these steps:

4.1 Download Android SDK Platform-Tools:

# Change to the directory where platform-tools will be stored
cd /mnt/case_sensitive
# Download platform-tools
wget https://dl.google.com/android/repository/platform-tools-latest-linux.zip
# Unzip platform-tools
unzip platform-tools-latest-linux.zip

4.2 Configure Environment Variables:

To use adb and fastboot commands from anywhere, you need to add the platform-tools directory to your PATH.

Edit the ~/.bashrc file

nano ~/.bashrc

Add the following line at the end of the file

export PATH=$PATH:/mnt/case_sensitive/platform-tools

Then reload the .bashrc file

source ~/.bashrc

4.3 Verify Configuration

You can check if adb is configured successfully with the following command

adb version

Test the connection to the device, ensuring your Android device is connected via USB, and that Developer Mode and USB Debugging are enabled.

adb devices

This will list the connected devices.

5. Mirror Settings

Find the path where repo is located

which repo

Edit repo

nano /home/cyrus/bin/repo

You can see that repo will prioritize the REPO_URL environment variable; otherwise, it defaults to googlesource.

Use the following script to set the REPO_URL environment variable to the Tsinghua University mirror, solving the issue of accessing googlesource from within China, and modify .gitconfig to replace the URL for accessing the LineageOS repository with the Tsinghua University mirror.

add_mirrors.sh (Set Mirror)

#!/bin/bash

export REPO_URL=https://mirrors.tuna.tsinghua.edu.cn/git/git-repo/
echo "REPO_URL="$REPO_URL

# Define the configuration to be added
config=$(cat <<EOF
[url "https://mirrors.tuna.tsinghua.edu.cn/git/git-repo"]
    insteadof = https://gerrit.googlesource.com/git-repo
[url "https://mirrors.tuna.tsinghua.edu.cn/git/lineageOS/"]
    insteadof = https://review.lineageos.org/
[url "https://mirrors.tuna.tsinghua.edu.cn/git/AOSP/"]
    insteadof = https://android.googlesource.com/
[url "https://mirrors.tuna.tsinghua.edu.cn/git/lineageOS/LineageOS/"]
    insteadof = https://github.com/LineageOS/
EOF
)

# Check if the configuration already exists in ~/.gitconfig
if grep -q "https://mirrors.tuna.tsinghua.edu.cn/git/git-repo" ~/.gitconfig; then
    echo "URL replacement already exists, no duplicate addition made."
else
    # If the configuration does not exist, add it to ~/.gitconfig
echo "$config" >> ~/.gitconfig
echo "URL replacement added to ~/.gitconfig"
fi


cat ~/.gitconfig

remove_mirrors.sh (Remove Mirror)

#!/bin/bash

unset REPO_URL
echo "REPO_URL="$REPO_URL

# Use sed command to delete the entire URL configuration block, including the URL and related insteadof lines
sed -i '/\[url "https:\/\/mirrors\.tuna\.tsinghua\.edu\.cn\/git\/git-repo"\]/,+1d' ~/.gitconfig
sed -i '/\[url "https:\/\/mirrors\.tuna\.tsinghua\.edu\.cn\/git\/lineageOS\/"\]/,+1d' ~/.gitconfig
sed -i '/\[url "https:\/\/mirrors\.tuna\.tsinghua\.edu\.cn\/git\/AOSP"\]/,+1d' ~/.gitconfig
sed -i '/\[url "https:\/\/mirrors\.tuna\.tsinghua\.edu\.cn\/git\/lineageOS\/LineageOS"\]/,+1d' ~/.gitconfig

echo "URL replacement removed from ~/.gitconfig"


cat ~/.gitconfig

Grant execution permissions to the script files

chmod +x add_mirrors.sh remove_mirrors.sh

Set to use the mirror

./add_mirrors.sh

6. Download Source Code

Create a directory

mkdir lineage-17.1

Change to the lineageos directory

cd lineage-17.1

If you can access GitHub normally, use the following command to initialize the repo

repo init -u https://github.com/LineageOS/android.git -b lineage-17.1 --git-lfs --depth=1

Otherwise, use the Tsinghua University mirror to initialize the repo and modify default.xml

repo init -u https://mirrors.tuna.tsinghua.edu.cn/git/lineageOS/LineageOS/android.git -b lineage-17.1 --git-lfs --depth=1\

Finally, sync the source code

repo sync

Or use the following command to download a shallow clone of the source code

repo sync --no-clone-bundle --current-branch --no-tags -j$(nproc)

This will shallow clone the latest LineageOS source code for the current branch, saving download time and space.

7. Resolve WebView Sync Failure Issues

error: Unable to fully sync the tree
error: Checking out local projects failed.
Failing repos:
external/chromium-webview/prebuilt/arm
external/chromium-webview/prebuilt/arm64
external/chromium-webview/prebuilt/x86
external/chromium-webview/prebuilt/x86_64
Try re-running with "-j1 --fail-fast" to exit at the first error.
================================================================================
Repo command failed due to the following `SyncError` errors:
Cannot initialize work tree for LineageOS/android_external_chromium-webview_prebuilt_arm
Cannot initialize work tree for LineageOS/android_external_chromium-webview_prebuilt_arm64
Cannot initialize work tree for LineageOS/android_external_chromium-webview_prebuilt_x86
Cannot initialize work tree for LineageOS/android_external_chromium-webview_prebuilt_x86_64

Syncing WebView from the mirror address keeps failing

Delete chromium-webview/prebuilt

rm -rf external/chromium-webview/prebuilt/*

Execute remove_mirrors.sh to remove the mirror, enable the proxy, and re-sync from GitHub.

repo sync --no-clone-bundle --current-branch --no-tags -j$(nproc)

8. Manually Add Device Repository

Create wayne.xml in .repo/local_manifests to manually add the device configuration repository for wayne (Xiaomi 6X).

Execute the command nano .repo/local_manifests/wayne.xml

mkdir .repo/local_manifests
nano .repo/local_manifests/wayne.xml

Configure Device tree, Common tree, Kernel, Vendor repositories

<manifest>
<remote  name="real_github"
           fetch="https://github.com" />

<project name="LineageOS-MI-A2-MI-6X/android_device_xiaomi_wayne" path="device/xiaomi/wayne" remote="real_github" revision="lineageos-17.1"/>
<project name="LineageOS-MI-A2-MI-6X/android_device_xiaomi_sdm660-common" path="device/xiaomi/sdm660-common" remote="real_github" revision="lineageos-17.1"/>
<project name="LineageOS-MI-A2-MI-6X/android_kernel_xiaomi_sdm660" path="kernel/xiaomi/sdm660" remote="real_github" revision="master"/>
<project name="LineageOS-MI-A2-MI-6X/android_vendor_xiaomi_sdm660-common" path="vendor/xiaomi/sdm660-common" remote="real_github" revision="master"/>
<project name="LineageOS-MI-A2-MI-6X/android_vendor_xiaomi_wayne-common" path="vendor/xiaomi/wayne-common" remote="real_github" revision="master"/>
</manifest>

Where:

• • name=”GitHub Username/Repository Name”
• • path is the location where the code is stored.

Kernel: The kernel is the core of the operating system, responsible for the interaction between hardware and software. The Android kernel is developed based on the Linux kernel, managing device resources and hardware drivers.

Device Tree: The device tree is a hardware description file that tells the operating system the hardware layout of the device, avoiding tight coupling of kernel code with specific hardware. The device tree is usually located in the device/ directory and contains device-specific configurations.

Common Tree: The common tree contains generic code and configurations shared by multiple devices. For example, some devices share the same hardware platform (like sm7250), and these configurations are placed in the Common Tree to avoid duplicate code.

Vendor Tree: The Vendor Tree contains proprietary binary drivers, libraries, and other software components provided by specific devices or hardware vendors (like Qualcomm, Xiaomi). These components are critical for the device to function correctly, especially for proprietary hardware features (like modems, cameras, GPUs, etc.).

The Vendor Tree is usually located in the vendor/ directory and contains closed-source components provided by the device manufacturer. Unlike the Kernel and Device Tree, it involves hardware-related binary files and libraries rather than kernel or hardware descriptions.

After completing this, run repo sync to sync the source code

repo sync --no-clone-bundle --current-branch --no-tags -j$(nproc)

Or manually clone it

git clone https://github.com/LineageOS-MI-A2-MI-6X/android_device_xiaomi_wayne.git device/xiaomi/wayne
git clone https://github.com/LineageOS-MI-A2-MI-6X/android_device_xiaomi_sdm660-common.git device/xiaomi/sdm660-common
git clone https://github.com/LineageOS-MI-A2-MI-6X/android_kernel_xiaomi_sdm660.git kernel/xiaomi/sdm660
git clone https://github.com/LineageOS-MI-A2-MI-6X/android_vendor_xiaomi_sdm660-common.git vendor/xiaomi/sdm660-common
git clone https://github.com/LineageOS-MI-A2-MI-6X/android_vendor_xiaomi_wayne-common.git vendor/xiaomi/wayne-common

Proxy Settings

Since the compilation process requires connecting to GitHub to download device trees and kernels, you need to set up a proxy first.

For proxy settings in Linux, you can refer tothis article^[2].

Cache Settings

Create a cache directory

mkdir -p /mnt/case_sensitive/ccache

Add the cache configuration to the end of the environment variable configuration file .bashrc

cat >> ~/.bashrc <<EOF
# Use cache
export USE_CCACHE=1
# ccache file path
export CCACHE_EXEC=/usr/bin/ccache
# Set cache directory
export CCACHE_DIR=/mnt/case_sensitive/ccache
EOF

Execute the following command to make the configuration effective

source ~/.bashrc

Set the maximum cache space to 50GB

ccache -M 50G

Enable ccache compression to reduce the disk space occupied by cache files

ccache -o compression=true

Source Code Compilation

1. Initialize the Compilation Environment

# Initialize the compilation environment
source build/envsetup.sh

# Set the compilation target
# If the local device repository is not available, it will download the device's Device tree and Kernel from the LineageOS repository
breakfast wayne

2. Supplement Vendor Files

Since vendor files are closed-source and cannot be directly included due to copyright reasons, LineageOS does not provide vendor files directly.

If the breakfast command indicates missing vendor files

In file included from build/make/core/config.mk:291:
In file included from build/make/core/envsetup.mk:266:
vendor/xiaomi/wayne-common/wayne-common-vendor.mk:782: error: _nic.PRODUCTS.[[device/xiaomi/wayne/lineage_wayne.mk]]: "vendor/xiaomi/wayne/wayne-vendor.mk" does not exist.
16:24:01 dumpvars failed with: exit status 1
In file included from build/make/core/config.mk:291:
In file included from build/make/core/envsetup.mk:266:
vendor/xiaomi/wayne-common/wayne-common-vendor.mk:782: error: _nic.PRODUCTS.[[device/xiaomi/wayne/lineage_wayne.mk]]: "vendor/xiaomi/wayne/wayne-vendor.mk" does not exist.
16:24:01 dumpvars failed with: exit status 1

According to the error message, you can supplement the corresponding vendor files in one of the following two ways

2.1 Use TheMuppets Vendor Repository

In the LineageOS project, some vendor files for devices are maintained by the community and stored in a repository called TheMuppets.

Repository address: https://github.com/orgs/TheMuppets/repositories

Clone the vendor repository to your local machine

git clone https://github.com/TheMuppets/proprietary_vendor_xiaomi_sdm660-common.git vendor/xiaomi/sdm660-common

git clone https://github.com/TheMuppets/proprietary_vendor_xiaomi_wayne-common.git vendor/xiaomi/wayne-common

git clone https://github.com/TheMuppets/proprietary_vendor_xiaomi_wayne.git vendor/xiaomi/wayne

2.2 Extract from the Device

Note: This step requires the device to have the current compilation branch of LineageOS installed. (You can flash it first and then extract)

Ensure your device is connected to the computer via USB, with adb debugging and root enabled, and located in the device/xiaomi/wayne directory

In this directory, you can usually find two key files:

• • extract-files.sh: A script used to extract vendor files from the device or firmware.
• • proprietary-files.txt: This file lists all the vendor files required by the device.

Run the extract-files.sh script

./extract-files.sh

The vendor driver files will be automatically pulled into the vendor/xiaomi folder.

3. Start Compilation

# Go back to the root directory of the Android source tree
croot
# Start compilation
brunch wayne

Resolve Case Sensitivity Issues in WSL During Compilation

21:38:08 ************************************************************
21:38:08 You are building on a case-insensitive filesystem.
21:38:08 Please move your source tree to a case-sensitive filesystem.
21:38:08 ************************************************************
21:38:08 Case-insensitive filesystems not supported

1. Create a Case-Sensitive Filesystem

Create a 300GB ext4 filesystem image file and mount it to /mnt/case_sensitive to provide a case-sensitive filesystem

# Create a 300GB empty file
dd if=/dev/zero of=/mnt/e/case_sensitive.img bs=1G count=300


# Format this file as an ext4 filesystem
mkfs.ext4 /mnt/e/case_sensitive.img

# Create a new mount point directory
sudo mkdir /mnt/case_sensitive

# Mount the formatted file to the newly created mount point
sudo mount /mnt/e/case_sensitive.img /mnt/case_sensitive

# Copy your LineageOS source directory to the newly mounted virtual disk
# -a: Archive mode, meaning recursively copy directories and preserve symlinks, permissions, timestamps, owners, etc.
# -v: Show detailed information.
# --progress: Show file transfer progress.
sudo rsync -av --progress /mnt/e/android_source_code/lineageos/ /mnt/case_sensitive/lineageos/
# Or
# Move your LineageOS source directory to the newly mounted virtual disk
sudo mv /mnt/e/android_source_code/lineageos /mnt/case_sensitive/

cd /mnt/case_sensitive/lineageos

To ensure case_sensitive.img is automatically mounted to /mnt/case_sensitive at each system startup.

1. 1. Open the /etc/fstab file

sudo nano /etc/fstab

1. 2. Add the following line

/mnt/e/case_sensitive.img  /mnt/case_sensitive  ext4  loop  0  0

2. Access case_sensitive from Windows

The access path is as follows:

\\wsl.localhost\Ubuntu\mnt\case_sensitive

Ensure Windows users have sufficient permissions for this directory. You may need to set some permissions in WSL

sudo chmod -R 777 /mnt/case_sensitive

This way, you should be able to access and use the case-sensitive filesystem in WSL from Windows.

3. How to Expand case_sensitive.img if Space is Insufficient?

1. 1. Unmount the filesystem

sudo umount /mnt/case_sensitive

This command unmounts the currently mounted case_sensitive.img filesystem to ensure it is not in use during the expansion process.

1. 2. Increase the size of the image file

dd if=/dev/zero bs=1G count=100 >> /mnt/e/case_sensitive.img

Parameter explanation:

• • The dd command is used to append 100GB of space to the case_sensitive.img file.
• • if=/dev/zero: Indicates the input file is /dev/zero, a device file that outputs an infinite number of zero bytes.
• • bs=1G: Indicates the block size is 1GB.
• • count=100: Indicates writing 100 blocks of 1GB.
• •
  

  /mnt/e/case_sensitive.img: Indicates appending the output to the existing case_sensitive.img file.

1. 3. Check and Repair the Filesystem

sudo e2fsck -f /mnt/e/case_sensitive.img

Parameter explanation:

• • The e2fsck command is used to check and repair ext2/ext3/ext4 filesystems.
• • The -f option forces a filesystem check even if the filesystem appears clean.

1. 4. Resize the Filesystem

sudo resize2fs /mnt/e/case_sensitive.img

The resize2fs command is used to resize ext2/ext3/ext4 filesystems to fit the new image file size.

1. 5. Check the Partition Table

First, use parted to check and adjust the partition table.

sudo parted /mnt/e/case_sensitive.img

In parted, execute the following command

(parted) print

This will print the current partition information. Then, use the following command to resize the partition

(parted) resizepart 1 100%

Exit parted

(parted) quit

1. 6. Remount the Filesystem

sudo mount /mnt/e/case_sensitive.img /mnt/case_sensitive

By following these steps, you can expand the space of case_sensitive.img without affecting existing data.

Resolve Insufficient Memory During Compilation

21:38:07 You are building on a machine with 7.62GB of RAM
21:38:07
21:38:07 The minimum required amount of free memory is around 16GB,
21:38:07 and even with that, some configurations may not work.
21:38:07
21:38:07 If you run into segfaults or other errors, try reducing your
21:38:07 -j value.
21:38:07 ************************************************************

Create Virtual Memory

# Create an 8GB file, located at /mnt/case_sensitive/swapfile. fallocate is a tool for quickly creating large files.
sudo fallocate -l 8G /mnt/case_sensitive/swapfile

# Change the permissions of /swapfile so that only the owner (root) has read and write permissions. This is for security, to prevent other users from accessing the swap file.
sudo chmod 600 /mnt/case_sensitive/swapfile

# Initialize /mnt/case_sensitive/swapfile as swap space. This command sets the filesystem flag to inform the operating system that this is a swap file.
sudo mkswap /mnt/case_sensitive/swapfile

# Enable /mnt/e/swapfile as swap space. This command activates the swap file for system use.
sudo swapon /mnt/case_sensitive/swapfile

# Check the usage of swap space
swapon --show

If memory is still insufficient?

Change the virtual memory size from 8G to 16G

# Turn off the current swap file
sudo swapoff /mnt/case_sensitive/swapfile

# Create a new 16G swap file
sudo fallocate -l 16G /mnt/case_sensitive/swapfile

# Set the permissions of the swap file to 600, ensuring only the root user can read and write to it.
sudo chmod 600 /mnt/case_sensitive/swapfile

# Format the swap file as swap
sudo mkswap /mnt/case_sensitive/swapfile

# Enable the new swap file
sudo swapon /mnt/case_sensitive/swapfile

# Use swapon --show or free -h to verify that the new swap file has been correctly enabled.
swapon --show
# Or
free -h

To ensure /mnt/case_sensitive/swapfile remains effective after reboot, add it to the /etc/fstab file

echo '/mnt/case_sensitive/swapfile swap swap sw 0 0
' | sudo tee -a /etc/fstab

After setting up, compile again. If the actual physical memory does not exceed 16G, the prompt may still exist, but it will not affect normal compilation.

WSL defaults to setting the maximum available memory to 50% of the actual physical memory. If you want to modify the maximum available memory for WSL, you can do so by modifying .wslconfig:

[wsl2]
memory=16GB

Resolve Compilation Errors

‘duplicate entry for genfs entry *’ at token ‘genfscon’

FAILED: out/target/product/wayne/obj/ETC/sepolicy_neverallows_intermediates/sepolicy_neverallows
/bin/bash -c "(ASAN_OPTIONS=detect_leaks=0 out/host/linux-x86/bin/checkpolicy -M -c             30 -o out/target/product/wayne/obj/ETC/sepolicy_neverallows_intermediates/sepolicy_neverallows.tmp out/target/product/wayne/obj/ETC/sepolicy_neverallows_intermediates/policy.conf ) && (out/host/linux-x86/bin/sepolicy-analyze out/target/product/wayne/obj/ETC/sepolicy_neverallows_intermediates/sepolicy_neverallows.tmp neverallow -w -f out/target/product/wayne/obj/ETC/sepolicy_neverallows_intermediates/policy_2.conf ||      ( echo "" 1>&&2;      echo "sepolicy-analyze failed. This is most likely due to the use" 1>&&2;      echo "of an expanded attribute in a neverallow assertion. Please fix" 1>&&2;        echo "the policy." 1>&&2;      exit 1 ) ) && (touch out/target/product/wayne/obj/ETC/sepolicy_neverallows_intermediates/sepolicy_neverallows.tmp ) && (mv out/target/product/wayne/obj/ETC/sepolicy_neverallows_intermediates/sepolicy_neverallows.tmp out/target/product/wayne/obj/ETC/sepolicy_neverallows_intermediates/sepolicy_neverallows )"
device/xiaomi/sdm660-common/sepolicy/vendor/genfs_contexts:31:ERROR 'duplicate entry for genfs entry (sysfs, /devices/soc/800f000.qcom,spmi/spmi-0/spmi0-00/800f000.qcom,spmi:qcom,pm660@0:qcom,pm660_rtc/rtc)' at token 'genfscon' on line 85793:
# Touchscreen
genfscon proc /nvt_wake_gesture                                 u:object_r:proc_dt2w:s0
checkpolicy:  error(s) encountered while parsing configuration

There is a duplicate genfscon entry in the sepolicy configuration file.

The path /devices/soc/800f000.qcom,spmi/spmi-0/spmi0-00/800f000.qcom,spmi:qcom,pm660@0:qcom,pm660_rtc/rtc is defined twice.

Find and remove the duplicate definition in the device/xiaomi/sdm660-common/sepolicy/vendor/genfs_contexts file.

Clear the cache and recompile

make clean
brunch wayne

Compilation Complete

After compilation, you can find the following two zip files in the out/target/product/wayne directory:

• • lineage-17.1-20240914-UNOFFICIAL-wayne.zip is the complete LineageOS ROM, typically used for fresh installations or re-flashing devices.
• • lineage_wayne-ota-eng.cyrus.zip is an OTA update package, possibly used for incremental updates to existing LineageOS installations, typically not used for first-time flashing.

Flashing

Enter recovery, format data first, then use adb sideload to start flashing

Wait for the flashing to complete, then reboot the system.

Related Links:

• • A Guide to Flashing LineageOS from Scratch: Recovery + Sideload Full Process Practical Guide^[3]
• • https://wiki.lineageos.org/devices/wayne/build/
• • [ROM][OTA][10.x] LineageOS 17.1 Unofficial [wayne/ Mi 6X]^[4]

Reference Links

<span>[1]</span> Android SDK Platform-Tools: https://developer.android.com/tools/releases/platform-tools?hl=zh-cn<span>[2]</span> This article: https://cyrus-studio.github.io/blog/posts/linux%E4%B8%8B%E4%BB%A3%E7%90%86%E8%AE%BE%E7%BD%AE/<span>[3]</span> A Guide to Flashing LineageOS from Scratch: Recovery + Sideload Full Process Practical Guide: https://cyrus-studio.github.io/blog/posts/%E6%95%99%E4%BD%A0%E4%BB%8E%E9%9B%B6%E5%88%B7%E5%85%A5-lineageosrecovery-+-sideload-%E5%85%A8%E6%B5%81%E7%A8%8B%E5%AE%9E%E6%93%8D%E6%8C%87%E5%8D%97/<span>[4]</span> [ROM][OTA][10.x] LineageOS 17.1 Unofficial [wayne/ Mi 6X]: https://xdaforums.com/t/rom-ota-10-x-lineageos-17-1-unofficial-wayne-mi-6x.3989193/