Template:S5P4418BuildFromSource

1 Make Your Own OS Image

1.1 Install Cross Compiler

1.1.1 Install arm-linux-gcc 4.9.3

Download the compiler package:

git clone https://github.com/friendlyarm/prebuilts.git -b master --depth 1
cd prebuilts/gcc-x64
cat toolchain-4.9.3-armhf.tar.gz* | sudo tar xz -C /

Then add the compiler's directory to "PATH" by appending the following lines in "~/.bashrc":

export PATH=/opt/FriendlyARM/toolchain/4.9.3/bin:$PATH
export GCC_COLORS=auto

Execute "~/.bashrc" to make the changes take effect. Note that there is a space after the first ".":

. ~/.bashrc

This compiler is a 64-bit one therefore it cannot be run on a 32-bit Linux machine. After the compiler is installed you can verify it by running the following commands:

arm-linux-gcc -v
Using built-in specs.
COLLECT_GCC=arm-linux-gcc
COLLECT_LTO_WRAPPER=/opt/FriendlyARM/toolchain/4.9.3/libexec/gcc/arm-cortexa9-linux-gnueabihf/4.9.3/lto-wrapper
Target: arm-cortexa9-linux-gnueabihf
Configured with: /work/toolchain/build/src/gcc-4.9.3/configure --build=x86_64-build_pc-linux-gnu
--host=x86_64-build_pc-linux-gnu --target=arm-cortexa9-linux-gnueabihf --prefix=/opt/FriendlyARM/toolchain/4.9.3
--with-sysroot=/opt/FriendlyARM/toolchain/4.9.3/arm-cortexa9-linux-gnueabihf/sys-root --enable-languages=c,c++
--with-arch=armv7-a --with-tune=cortex-a9 --with-fpu=vfpv3 --with-float=hard
...
Thread model: posix
gcc version 4.9.3 (ctng-1.21.0-229g-FA)

1.2 Compile Linux kernel for FriendlyCore/Lubuntu/EFlasher

1.2.1 Compile Kernel

• Download Kernel Source Code

git clone https://github.com/friendlyarm/linux.git -b nanopi2-v4.4.y --depth 1
cd linux

The {{{1}}}'s kernel source code is in the "nanopi2-v4.4.y" branch.You need to switch to this branch.

• Compile Ubuntu Kernel

touch .scmversion
make ARCH=arm nanopi2_linux_defconfig
make ARCH=arm

After your compilation succeeds an "arch/arm/boot/zImage" will be generated and a DTB file(s5p4418-nanopi2-rev*.dtb) will be generated in the "arch/arm/boot/dts/" directory. You can use them to replace the existing zImage and DTB files in the boot partition of your bootable SD card.

1.2.2 Use Your Generated Kernel

• Update kernel in SD card

If you use an SD card to boot Ubuntu you can copy your generated zImage and DTB files to your SD card's boot partition(e.g. partition 1 /dev/sdX1).

• Update kernel in eMMC

If you boot your board from eMMC you can update your kernel file by following the steps below:
1) Usually after OS is loaded eMMC's boot partition (in our example eMMC's device name was /dev/mmcblk0p1) will be automatically mounted and you can verify that by running "mount"
2) Connect your board to a host PC running Ubuntu and copy the zImage and DTB files to eMMC's boot partition
3) Or you can copy your generated kernel file to an external storage card(e.g. an SD card or a USB drive), connect the storage card to your board the move the file from the card to eMMC's boot partition
4) After update is done type "reboot" to reboot your board. Note: don't just directly disconnect your board from its power source or press the reset button to reboot the board. These actions will damage your kernel file

• Generate Your boot.img

Refer to this repo: https://github.com/friendlyarm/sd-fuse_s5p4418

1.3 Compile Linux kernel for Android7

The Android 7.1.2 source code already contains the pre-compiled kernel. If you need to customize it, you can compile the kernel according to the following guide.

git clone https://github.com/friendlyarm/linux.git -b nanopi2-v4.4.y --depth 1
cd linux
touch .scmversion
make ARCH=arm nanopi2_nougat_defconfig
make ARCH=arm

The newly generated kernel is arch/arm/boot/zImage，The new DTB file is also included under the directory arch/arm/boot/dts/.(s5p4418-nanopi2-rev*.dtb).
If you only want to debug the kernel, you can quickly update it with adb:

adb root; adb shell mkdir /storage/sdcard1/; adb shell mount -t ext4 /dev/block/mmcblk0p1 /storage/sdcard1/;
adb push arch/arm/boot/zImage arch/arm/boot/dts/s5p4418-nanopi2-rev*.dtb /storage/sdcard1/

If you want to generate boot.img for burning, you can copy the kernel zImage and DTB files to the Android7 source code directory: device/friendlyelec/nanopi2/boot, then recompile Android7.

1.4 Compile U-Boot for Android7/FriendlyCore/Lubuntu/EFlasher

Download the U-Boot source code and compile it. Note that the github's branch is nanopi2-v2016.01:

git clone https://github.com/friendlyarm/u-boot.git 
cd u-boot
git checkout nanopi2-v2016.01
make s5p4418_nanopi2_defconfig
make CROSS_COMPILE=arm-linux-

After your compilation succeeds a bootloader.img will be generated. If you want to test it flash it to your installation SD card to replace an existing U-Boot v2016.01 file via fastboot, sd-fuse_s5p4418 or eflasher ROM.
For Android7: Copy bootloader.img to Android7 source directory device/friendlyelec/nanopi2/boot, then recompile Android7.
Note: you cannot use mixed U-Boot files. For example you cannot use fastboot to update an existing U-Boot V2014.07 and you cannot use bootloader.img to replace an existing u-boot.bin

1.5 Compile Android 7.1.2

1.5.1 Install Cross Compiler

Install 64 bit Ubuntu 16.04 on your host PC.

sudo apt-get install bison g++-multilib git gperf libxml2-utils make python-networkx zip
sudo apt-get install flex curl libncurses5-dev libssl-dev zlib1g-dev gawk minicom
sudo apt-get install openjdk-8-jdk
sudo apt-get install exfat-fuse exfat-utils device-tree-compiler liblz4-tool

For more details refer to https://source.android.com/source/initializing.html 。

1.5.2 Download Android7 Source Code

There are two ways to download the source code:

• repo archive file on netdisk

Netdisk URL: Click here
File location on netdisk：sources/s5pxx18-android-7.git-YYYYMMDD.tgz (YYYYMMDD means the date of packaging)
After extracting the repo package from the network disk, you need to execute the sync.sh script, which will pull the latest code from gitlab:

tar xvzf /path/to/netdisk/sources/s5pxx18-android-7.git-YYYYMMDD.tgz
cd s5pxx18-android-7
./sync.sh

• git clone from gitlab

{{{1}}} source code is maintained in gitlab, You can download it by running the following command:

git clone https://gitlab.com/friendlyelec/s5pxx18-android-7.git -b master

1.5.3 Compile Android7

cd s5pxx18-android-7
source build/envsetup.sh
lunch aosp_nanopi2-userdebug
make -j8

After your compilation succeeds the following files will be generated in the "out/target/product/nanopi2/" directory.

filename	partition	Description
bl1-mmcboot.bin	raw	boot firmware
loader-mmc.img	raw	boot firmware
bl_mon.img	raw	boot firmware
bootloader.img	raw	uboot-v2016.01
env.conf	-	Uboot environment variable containing Android kernel command line parameters
boot.img	boot	kernel zImage, DTBs; logo; Android ramdisk
cache.img	cache	-
userdata.img	userdata	-
system.img	system	-
partmap.txt	-	Partition description file