eepymeowers

How to build Android for a device

Pre-requisites

Make sure the machine you'll be building on has the recommended requirements; the bare minimum is 32GB RAM, if you are going to use zram during the build. Decreasing the job count will help with RAM usage, and could even possibly get it to build on 8GB RAM, but I recommend 48GB or more of RAM.

Create the directory you'll do your build in with mkdir crDroid && cd crDroid (substitute crDroid for whatever you want the folder to be called, it doesn't need to be called anything specific)

For Debian 13 and newer (as of Dec 2025) (or any distro based on Debian 13 or newer, with these packages in the repos) run this: `sudo apt install git-core gnupg flex bc ccache flex g++-multilib gcc-multilib git git-lfs gperf imagemagick liblz4* libncurses-dev libsdl1.2-dev libssl-dev bison build-essential zip curl zlib1g-dev libc6-dev-i386 x11proto-core-dev libx11-dev lib32z1-dev libgl1-mesa-dev libxml2-utils xsltproc unzip fontconfig libxml2 lzop pngcrush rsync schedtool

ThEMarD

git remote add clo https://git.codelinaro.org/clo/la/kernel/msm-5.4 && git fetch clo
./best-caf-kernel.py "LA*" | tee ~/Desktop/best_caf_tag.txt

number of tags to check: 273
LA.AU.0.2.0.r1-00500-gen3_gvmgh.0 has 3593778 lines changed
LA.AU.0.2.0.r1-00500-gen3_gvmgh.0 is the new best match with 3593778 lines changed
LA.AU.0.2.0.r1-01300-gen3_gvmgh.0 has 3965658 lines changed
LA.AU.0.2.0.r1-01500-gen3_gvmgh.0 has 3965658 lines changed
LA.AU.0.2.0.r1-01800-gen3_gvmgh.0 has 3965614 lines changed
LA.AU.0.2.0.r1-02100-gen3_gvmgh.0 has 3972551 lines changed

SebaUbuntu

Generate framework compatibility matrix from fqnames

• Download these 2 files
• Compile AOSP without fcm from stock and wait for check_vintf to error out
• Delete Python prefix from all lines (e.g. checkvintf E 06-24 00:30:22 49120 49120 check_vintf.cpp:554])
• Paste the result in fqnames.txt
• Launch the script

verNANDo57

Workarounds for building R on 8GB RAM environment:

1. At the start of the build:
[ 99% 138/139] /mnt/ssd/lineage/out/soong/.bootstrap/bin/soong_build /mnt/ssd/lineage/out/soong/build.ninja
This used to take around 30mins, after enabling zram now it takes around 30secs (thanks to @kdrag0n for the zram idea) which is on par with what happens in 16GB RAM building environments

sudo apt install zram-config for installing zram-config package
sudo nano /etc/fstab and add a # in front of the swap disk if you have one and then reboot
After booting cat /proc/swaps to check if zram is enabled or not

ThEMarD

Make sure the device's and/or commonized device proprietary-files are updated with the same blobs that you want in your proprietary vendor repo.

Next, to use the kang and section mode we need the switches "-k -s". -k tells extract-files to only kang/pull updated blobs without deleting any blobs. -s tells it to only update ones from a commented section of your proprietary-files.

for example, if i have this in my proprietary-files

# ADSP - from oneplus3t - OnePlus/OnePlus3/OnePlus3T:9/PKQ1.181203.001/1911042108 - OOS 9.0.6
vendor/lib/libadsp_hvx_callback_skel.so
vendor/lib/libadsp_hvx_stub.so

ThEMarD

Make sure the device's and/or commonized device proprietary-files are updated with the same blobs that you want in your proprietary vendor repo.

In my example, I'll use the LeEco Le Max 2 (x2), so I would then copy the current LeEco msm8996-common and then x2 blobs (just to clarify, I mean the blobs themselves within the proprietary folder) to the desktop in a folder named vendorblobs

Then open terminal in the device tree and...

./extract-files.sh ~/Desktop/vendorblobs/ | tee ~/Desktop/extractor.log

Check extractor.log to ensure it worked ok and there was no errors / not found.

DD3Boh

Useful things I'd otherwise forget

Systemd-boot

Fix your EFI entries after they get reset

This could happen because of a CMOS reset or other reasons, to reset the entries just:

• Boot into a live arch linux ISO
• Use fdisk -l to check the disks
• Mount the root partition to /mnt and the EFI partition to /mnt/efi
• Chroot into the partition with arch-chroot /mnt

ThEMarD

First you'll need to clone acdb_extract. I used the one by J510-Dev which is originally based on the one by luca020400.

git clone https://github.com/J510-Dev/acdb_extract

Then, as the README says you must generate the acdb header. For Qualcomm devices? The stock audio hal would be audio.primary.msm8996.so which is found on my stock ROM from /system/lib/hw/audio.primary.msm8996.so which I could just copy into the acdb_get folder... so for example, I'd use this:
./generate_acdb_data.sh audio.primary.msm8996.so

which will generate a file called acdb_data.h which is needed for the next step.

Since acdb_extract doesn't require being built in the AOSP environment? You can just build it using...

DD3Boh

First go here:

        https://wiki.codeaurora.org/xwiki/bin/QAEP/release

This site gives information about all msm soc release details with tag + android version

Search your msm here.. Check the latest one and look for correct android version and mark that tag.

Now open one of the following links (dependent on your linux kernel version)

karenyyng

Table Of Content

Skip to the relevant sections if needed.

• 2-min tutorial to do it the quick-and-dirty-way
• Concepts for resolving Git conflicts
• Setting up different editors / tool for using git mergetool
  • Finding out what mergetool editors are supported
• mergetool simple code example for vimdiff
  • Resolving conflict from a Git pull
• Other great references and tutorials