kernel build steps

[lucastanure]

Hi,

Can you post instructions on how to build this kernel?
What's the cross compiler? Config used?

Thanks
Lucas

[KonstaT]

There's three different ways to compile the kernel.

1. Compiling kernel as part of Android build works for Pi 3 & Pi 4 for both lineage-16.0 & lineage-17.1 branches.

Setup build environment:
https://source.android.com/setup/build/initializing
https://source.android.com/setup/develop#installing-repo

E.g. for LineageOS 17.1 on Pi 4:

repo init -u git://github.com/LineageOS/android.git -b lineage-17.1
curl --create-dirs -L -o .repo/local_manifests/manifest_brcm_rpi.xml -O -L https://raw.githubusercontent.com/lineage-rpi/android_local_manifest/lineage-17.1/manifest_brcm_rpi.xml
repo sync

You can also add '--depth=1' parameter to the first command to create a shallow clone and save time and bandwidth on syncing the sources (repo init -u git://github.com/LineageOS/android.git -b lineage-17.1 --depth=1).

To compile:

. build/envsetup.sh
lunch lineage_rpi4-userdebug
mka kernel

2. Building the kernel as standalone is also possible but requires some extra effort. It will save you from downloading the whole Android source code for this.

E.g. for LineageOS 18 on Pi 4:

Clone kernel source (https://github.com/lineage-rpi/android_kernel_brcm_rpi/tree/lineage-18.1).
Clone proprietaries to get firmware files (https://github.com/lineage-rpi/proprietary_vendor_brcm/tree/lineage-18.1).
Clone AOSP toolchains for 32-bit & 64-bit (https://android.googlesource.com/platform/prebuilts/gcc/linux-x86/arm/arm-linux-androideabi-4.9/+/refs/heads/pie-release & https://android.googlesource.com/platform/prebuilts/gcc/linux-x86/aarch64/aarch64-linux-android-4.9/+/refs/heads/pie-release).

git clone https://github.com/lineage-rpi/android_kernel_brcm_rpi -b lineage-18.1
git clone https://github.com/lineage-rpi/proprietary_vendor_brcm -b lineage-18.1
git clone https://android.googlesource.com/platform/prebuilts/gcc/linux-x86/arm/arm-linux-androideabi-4.9 -b pie-release
git clone https://android.googlesource.com/platform/prebuilts/gcc/linux-x86/aarch64/aarch64-linux-android-4.9 -b pie-release

Modify firmware path according to where you've saved them (https://github.com/lineage-rpi/android_kernel_brcm_rpi/blob/lineage-18.1/arch/arm/configs/lineageos_rpi4_defconfig#L1429 for 32-bit or https://github.com/lineage-rpi/android_kernel_brcm_rpi/blob/lineage-18.1/arch/arm64/configs/lineageos_rpi4_defconfig#L1441 for 64-bit). Also make note where you've saved the toolchain.

To compile 32-bit kernel execute from the root of kernel source (where X is the number of threads on your CPU for parallel jobs):

ARCH=arm CROSS_COMPILE=path/to/arm-linux-androideabi-4.9/bin/arm-linux-androidkernel- make lineageos_rpi4_defconfig
ARCH=arm CROSS_COMPILE=path/to/arm-linux-androideabi-4.9/bin/arm-linux-androidkernel- make zImage dtbs -jX

To compile 64-bit kernel execute from the root of kernel source (where X is the number of threads on your CPU for parallel jobs):

ARCH=arm64 CROSS_COMPILE=path/to/aarch64-linux-android-4.9/bin/aarch64-linux-androidkernel- make lineageos_rpi4_defconfig
ARCH=arm64 CROSS_COMPILE=path/to/aarch64-linux-android-4.9/bin/aarch64-linux-androidkernel- make Image dtbs -jX

3. Using separate kernel build environment.

For Android 12 kernel build refer to https://github.com/lineage-rpi/android_kernel_manifest/tree/lineage-19.1.
For Android 13 kernel build refer to https://github.com/lineage-rpi/android_kernel_manifest/tree/lineage-20.0.

[AmbientTech]

I created a android folder in my Documents where I store all 3 git files.

I have gotten all the way to
ARCH=arm CROSS_COMPILE=home/username/Documents/android/arm-linux-androideabi-4.9/bin/arm-linux-androidkernel- make zImage dtbs -j1

and I get this
make: *** No rule to make target 'zImage'. Stop.

What did I do wrong?

[KonstaT]

You need to be on the root of the kernel source directory to execute

ARCH=arm make lineageos_rpi4_defconfig
ARCH=arm CROSS_COMPILE=path/to/arm-linux-androideabi-4.9/bin/arm-linux-androidkernel- make zImage dtbs -jX

You have a used a relative path for the toolchain (home/...) where you would've needed an absolute one (/home/...).

[ezebongiovi]

Hi @KonstaT I'm having this error when trying to build lineage-16.0

[KonstaT]

@ezebongiovi As commented in lineage-rpi/android_local_manifest#8 (comment) I haven't released the full device specific source code for my LineageOS 16.0 & 17.1 builds (both Pi 3 & Pi 4). You can use these sources to build Linux kernel and other GPL licensed parts included in my images. There's also source code for the graphics drivers used in my builds if someone wants to work on that.

[wilsavery1]

Hi KonstaT,
I follow the step by step to Building the kernel as standalone.
for some reason I keep getting this errors.
root@builder1:~/kernel/android_kernel_brcm_rpi# ARCH=arm make lineageos_rpi4_defconfig

WARNING: unmet direct dependencies detected for GENERIC_GETTIMEOFDAY
Depends on [n]: HAVE_GENERIC_VDSO [=n]
Selected by [y]:

• HAVE_ARM_ARCH_TIMER [=y] && CPU_V7 [=y]

WARNING: unmet direct dependencies detected for GENERIC_GETTIMEOFDAY
Depends on [n]: HAVE_GENERIC_VDSO [=n]
Selected by [y]:

• HAVE_ARM_ARCH_TIMER [=y] && CPU_V7 [=y]

configuration written to .config

ARCH=arm CROSS_COMPILE=/root/kernel/arm-linux-androideabi-4.9/bin/arm-linux-androidkernel- make zImage dtbs -j4
ake: /root/kernel/arm-linux-androideabi-4.9/bin/arm-linux-androidkernel-gcc: No such file or directory
scripts/kconfig/conf --syncconfig Kconfig
./scripts/gcc-version.sh: 17: /root/kernel/arm-linux-androideabi-4.9/bin/arm-linux-androidkernel-gcc: not found
./scripts/gcc-version.sh: 18: /root/kernel/arm-linux-androideabi-4.9/bin/arm-linux-androidkernel-gcc: not found
./scripts/gcc-version.sh: 19: /root/kernel/arm-linux-androideabi-4.9/bin/arm-linux-androidkernel-gcc: not found
./scripts/gcc-version.sh: 17: /root/kernel/arm-linux-androideabi-4.9/bin/arm-linux-androidkernel-gcc: not found
./scripts/gcc-version.sh: 18: /root/kernel/arm-linux-androideabi-4.9/bin/arm-linux-androidkernel-gcc: not found
./scripts/gcc-version.sh: 19: /root/kernel/arm-linux-androideabi-4.9/bin/arm-linux-androidkernel-gcc: not found
./scripts/clang-version.sh: 11: /root/kernel/arm-linux-androideabi-4.9/bin/arm-linux-androidkernel-gcc: not found
init/Kconfig:34:warning: 'GCC_VERSION': number is invalid

Maybe you can point me in the right direction.

Thank you.

[KonstaT]

@wilsavery1 Check the path for the toolchain.

Where did you clone it? Did you clone the right branch (pie-release)? Change into the directory you cloned it and run 'pwd' to get the path.

[wilsavery1]

Thank you @KonstaT for you prompt response.
All source I got following the above instruction:
Clone kernel source (https://github.com/lineage-rpi/android_kernel_brcm_rpi/tree/lineage-17.1).
Clone proprietaries to get firmware files (https://github.com/lineage-rpi/proprietary_vendor_brcm/tree/lineage-17.1).
Clone AOSP toolchain (https://android.googlesource.com/platform/prebuilts/gcc/linux-x86/arm/arm-linux-androideabi-4.9/+/refs/heads/pie-release).

Now I encounter another issue (bellow)
Please note that my building machine is a MacOS.

Thank you again for your help.

scripts/extract-cert.c:21:10: scripts/sortextable.cfatal error:: 23:10: 'openssl/bio.h'fatal error : file not found'elf.h'
file not found
#include <elf.h>#include <openssl/bio.h>

     ^~~~~~~         ^~~~~~~~~~~~~~~

scripts/recordmcount.c:28:10: fatal error: 'elf.h' file not found
#include <elf.h>
^~~~~~~
1 error generated.
make[2]: *** [scripts/extract-cert] Error 1
make[2]: *** Waiting for unfinished jobs....
DTCO arch/arm/boot/dts/overlays/act-led.dtbo
DTC arch/arm/boot/dts/bcm2708-rpi-b-plus.dtb
In file included from scripts/selinux/mdp/mdp.c:36:
In file included from ./security/selinux/include/classmap.h:2:
In file included from ./include/uapi/linux/capability.h:17:
./include/uapi/linux/types.h:5:10: fatal error: 'asm/types.h' file not found
#include <asm/types.h>
^~~~~~~~~~~~~
In file included from scripts/selinux/genheaders/genheaders.c:18:
In file included from ./security/selinux/include/classmap.h:2:
In file included from ./include/uapi/linux/capability.h:17:
./include/uapi/linux/types.h:5:10: fatal error: 'asm/types.h' file not found
#include <asm/types.h>
^~~~~~~~~~~~~

[KonstaT]

Above instructions also specify that you clone the correct branches.

git clone https://github.com/lineage-rpi/android_kernel_brcm_rpi -b lineage-17.1
git clone https://github.com/lineage-rpi/proprietary_vendor_brcm -b lineage-17.1
git clone https://android.googlesource.com/platform/prebuilts/gcc/linux-x86/arm/arm-linux-androideabi-4.9 -b pie-release

There's a different toolchain for Mac (assuming you're using x86 one and not the new ARM kind).

git clone https://android.googlesource.com/platform/prebuilts/gcc/darwin-x86/arm/arm-linux-androideabi-4.9 -b pie-release

[wilsavery1]

Thank again @KonstaT.
I cloned the toolchain, double, and triple check my environment, made sure all path are correct.

I'm still getting the same error, still no luck.

scripts/sortextable.c:23:10: fatal error: 'elf.h' file not found
#include <elf.h>
^~~~~~~
DTC arch/arm/boot/dts/bcm2708-rpi-b-plus.dtb
scripts/recordmcount.c:28:10: fatal error: 'elf.h' file not found
#include <elf.h>
^~~~~~~
scripts/extract-cert.c:21:10: fatal error: 'openssl/bio.h' file not found
#include <openssl/bio.h>
^~~~~~~~~~~~~~~
1 error generated.
make[2]: *** [scripts/extract-cert] Error 1
make[2]: *** Waiting for unfinished jobs....
DTCO arch/arm/boot/dts/overlays/adafruit18.dtbo
1 error generated.
In file included from scripts/selinux/mdp/mdp.c:36:
In file included from ./security/selinux/include/classmap.h:2:
In file included from ./include/uapi/linux/capability.h:17:
./include/uapi/linux/types.h:5:10: fatal error: 'asm/types.h' file not found
#include <asm/types.h>
^~~~~~~~~~~~~
make[2]: *** [scripts/sortextable] Error 1
In file included from scripts/selinux/genheaders/genheaders.c:18:
In file included from ./security/selinux/include/classmap.h:2:
In file included from ./include/uapi/linux/capability.h:17:
./include/uapi/linux/types.h:5:10: fatal error: 'asm/types.h' file not found
#include <asm/types.h>
^~~~~~~~~~~~~

[KonstaT]

I'm not a MacOS user so I really don't know about that.

Google searching the first error tells that it seems to be some common problem on MacOS trying to build Linux natively.

Problem with missing openssl headers can happen on Linux as well and for that you need to install libssl-dev package. No idea what is the MacOS equivalent.

I need android on my rpi3 with alsa snd loop modul active, so I tried to build the kernel.

Therefor, I'm using docker. I'll leave the dockerfile here incase anyone needs to build the kernel.
NOTE that I'm not entirly sure if its ok to mix the branches lineage-17.1-4.19 and lineage-17.1 as described in the dockerfile, so mabye you want to replace lineage-17.1-4.19 with lineage-17.1 if you are not targeting the rpi3. Oh and make sure to remove the CONFIG_SND_ALOOP line if you don't need the alsa snd loop modul.

FROM ubuntu:focal
	
# Install dependencies
# Installing is split into three parts on purpose
# Combining the first two might fail because of tzdata
# After the second part, we installed all the basics so git cloning is possible
# Then we clone before installing the third dependency part, since clonig takes time
# and dependencies in the third part may change (and if they do, we don't have to clone
# again due to build caching)
RUN apt-get update \
        && TZ="Europe/Germany" DEBIAN_FRONTENTD="noninteractive" apt-get install -y --no-install-recommends \
		tzdata
RUN apt-get update \
        &&DEBIAN_FRONTENTD="noninteractive" apt-get install -y --no-install-recommends \
        nano \
        wget \
        tmux \
		git git-core\
		curl \
		ca-certificates ca-certificates-java ca-certificates-mono

# Clone the gits, do it in three commands since target branches may change
WORKDIR /app
RUN git clone https://android.googlesource.com/platform/prebuilts/gcc/linux-x86/arm/arm-linux-androideabi-4.9 -b pie-release
RUN git clone https://github.com/lineage-rpi/proprietary_vendor_brcm -b lineage-17.1
# I'm using the lineage-17.1-4.19 branch here instead of the lineage-17.1 branch since the later seems to lack the lineageos_rpi3_defconfig file
RUN git clone https://github.com/lineage-rpi/android_kernel_brcm_rpi -b lineage-17.1-4.19

# Install dependencies, part 3
RUN apt-get update \
        &&DEBIAN_FRONTENTD="noninteractive" apt-get install -y --no-install-recommends \
		make gcc flex bison build-essential zip unzip python3 bc \
		libssl-dev \
		openjdk-8-jdk gnupg gperf \
		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 liblz4-tool vboot-utils u-boot-tools \
		device-tree-compiler 
RUN update-alternatives --install /usr/bin/python python /usr/bin/python3 10

# Prepare build environment
ENV BUILD_CORES=4
ENV PI_GENERATION=4
ENV ARCH=arm
ENV CROSS_COMPILE=/app/arm-linux-androideabi-4.9/bin/arm-linux-androidkernel-
# Update firmware path
RUN sed -i 's+CONFIG_EXTRA_FIRMWARE_DIR="../../../vendor/brcm/rpi+CONFIG_EXTRA_FIRMWARE_DIR="/app/proprietary_vendor_brcm/rpi+g' /app/android_kernel_brcm_rpi/arch/arm/configs/lineageos_rpi${PI_GENERATION}_defconfig
# Enable alsa loopback
RUN sed -i 's+# CONFIG_SND_ALOOP is not set+CONFIG_SND_ALOOP=m+g' /app/android_kernel_brcm_rpi/arch/arm/configs/lineageos_rpi${PI_GENERATION}_defconfig

# Actual building
WORKDIR /app/android_kernel_brcm_rpi
RUN make lineageos_rpi${PI_GENERATION}_defconfig
RUN make zImage dtbs -j${BUILD_CORES}
# Get the result
WORKDIR /app
RUN mv /app/android_kernel_brcm_rpi/arch/arm/boot/zImage /app/kernel_rpi${PI_GENERATION}.img

So, now my question is, after building, how can I incorperate my kernel into the images you provide (I'm refering to these)?

Edit: Oh and @wilsavery1 I got the same problem during building, I think installing libssl-dev fixed this error.