Compiling Linux Kernel for Pixel 2 devices -- Bash script

wahoo_mybuild.sh

#!/bin/bash
# Purpose: Script for building AOSP code and Linux kernel for walleye using open-source toolchains. 
# Author: [email protected]
# License: Gnu GPL v. 2
# License is same as Linux kernel license, since the code helps compile the Linux kernel for a device
# Change these directory paths to point to your aosp and NDK folders.
export AOSP=~/src/aosp 
export CROSS_COMPILE=~/ndk/android-ndk-r16b/toolchains/aarch64-linux-android-4.9/prebuilt/linux-x86_64/bin/aarch64-linux-android-
# Change these if you are building for something other than walleye (Pixel 2) as needed.
export KERNELNAME=wahoo
export TARGETBUILD=walleye
export ARCH=arm64
export SUBARCH=arm64
export CLANG_TRIPLE=aarch64-linux-gnu-
export CLANG_PREBUILT_BIN=$AOSP/prebuilts/clang/host/linux-x86/clang-4053586/bin
export CC_CMD=${CLANG_PREBUILT_BIN}/clang

# These likely would not have to be changed.
export PATH=$PATH:$AOSP/prebuilts/misc/linux-x86/dtc:$AOSP/prebuilts/misc/linux-x86/libufdt

build_aosp()
{
    set -x
    cp arch/arm64/boot/dtbo.img $AOSP/device/google/${KERNELNAME}-kernel 
    cp arch/arm64/boot/Image.lz4-dtb $AOSP/device/google/${KERNELNAME}-kernel
    set +x
    # Uncomment if other drivers need to be also updated. The following paths are specific to walleye and may need
    # changes for your specific device.
    cp drivers/input/touchscreen/stm/*.ko $AOSP/device/google/${KERNELNAME}-kernel
    cp drivers/power/*.ko $AOSP/device/google/wahoo-kernel
    cp drivers/input/touchscreen/synaptics_dsx_htc/*.ko $AOSP/device/google/${KERNELNAME}-kernel
    cp drivers/input/touchscreen/lge/*.ko $AOSP/device/google/${KERNELNAME}-kernel
    cp drivers/input/touchscreen/lge/lgsic/*.ko $AOSP/device/google/${KERNELNAME}-kernel
     

    echo "Running lunch and make for ${TARGETBUILD}-userdebug in the $AOSP folder"
    pushd .
    cd $AOSP  || return 1
    . build/envsetup.sh || return 1
    lunch aosp_${TARGETBUILD}-userdebug || return 1
    # Alternative 1: Builds everything
    make -j48 || return 1
    # Alternative 2: The following may work if only the kernel is being updated
    # make bootimage
    popd
    return 0
}

flash_image()
{
    echo "Attempting to flash image..."
    pushd .
    cd $AOSP
    . build/envsetup.sh
    lunch aosp_${TARGETBUILD}-userdebug || return 1
    set -x
    adb reboot bootloader || return 1
    sleep 10
    echo "fastboot flashall -w"
    fastboot flashall -w || return 1
    set +x
    popd
    echo "Attempt to flash image done..."
}

# Make walleye_defconfig or appropriate kernel configuration file
set -x
echo "Building kernel: make ${KERNELNAME}_defconfig"
make ${KERNELNAME}_defconfig


# Build the kernel, using clang if needed.
if [ -z "${CC_CMD}" ];
then
    echo "Building kernel: make V=1 -j40"
    make V=1 -j40 || exit 1
else
    echo "Building kernel: make V=1 CC=${CC_CMD} -j40"
    make V=1 CC=${CC_CMD} -j40 || exit 1
fi
set +x

# Copy the kernel files to the AOSP tree and build it.
build_aosp || exit 1

# Flash the image to the connected device over adb. The device must be authorized for adb.
flash_image || exit 1

Hello,
It seems when you build kernel with GCC, then after AOSP build, the touch screen keeps unresponsive. Build kernel with CLANG will be always OK. Do you know what is the problem?

Hello,
It seems when you build kernel with GCC, then after AOSP build, the touch screen keeps unresponsive. Build kernel with CLANG will be always OK. Do you know what is the problem?

Hello, do you mean that before using this script , we should build msm kernel with CLANG and shouldn't build the msm kernel with GCC ? @huntcve

The official tutorial says that the android 8.0+ only supports to build with CLANG/LLVM. However, it doesn't say the msm kernel should to be built with CLANG.

So, is it true that the msm kernel should to be built with CLANG ?

Hello,
It seems when you build kernel with GCC, then after AOSP build, the touch screen keeps unresponsive. Build kernel with CLANG will be always OK. Do you know what is the problem?

Hello! When I compiled the kernel with clang, and use this script to compile aosp, the touchscreen still keeps unresponsive.
Do you know why? Which aosp and kernel 's branch do you choose? Thank you. @huntcve