2. Compile Linux5.10 firmware

2.1. Build the build environment

This chapter introduces the compilation environment of the Linux SDK

Note:

(1) It is recommended to develop in the Ubuntu 18.04 system environment. If other system versions are used, the compilation environment may need to be adjusted accordingly.

(2) Compile with ordinary user, do not compile with root user authority.

2.1.1. Download Firefly_Linux_SDK

First prepare an empty folder to place SDK, better under home, here we use ~/proj as example.

Attention: To avoid unnecessary errors, please do not place/unzip the SDK in VM shared folders or non-english directories.

Get SDK needs:

sudo apt update
sudo apt install -y repo git python
  • Method One

Download via repo, you can choose to get full SDK or BSP:

# Create SDK directory
mkdir ~/proj/rk356x_sdk-linux5.10
cd ~/proj/rk356x_sdk-linux5.10

## Full SDK
repo init --no-clone-bundle --repo-url https://gitlab.com/firefly-linux/git-repo.git --no-repo-verify -u https://gitlab.com/firefly-linux/manifests.git -b master -m rk356x_linux5.10_release.xml

## BSP (Only include some basic repositories and compile tools)
## BSP includes device/rockchip, docs, kernel, u-boot, rkbin, tools and cross-compile toolchian
repo init --no-clone-bundle --repo-url https://gitlab.com/firefly-linux/git-repo.git --no-repo-verify -u https://gitlab.com/firefly-linux/manifests.git -b master -m rk356x_linux5.10_bsp_release.xml
  • Method Two

Download Firefly_Linux_SDK sub-volume compressed package: rk356x_linux5.10_release_20231027_v1.2.1b

Extract the SDK:

# add execution permissions
cd /path/to/rk356x_linux5.10_release_20231027_v1.2.1b
chmod +x ./sdk_tools.sh

# create SDK directory
mkdir -p ~/proj/rk356x_sdk-linux5.10

# unzip
./sdk_tools.sh --unpack -C ~/proj/rk356x_sdk-linux5.10

# restore working directory
./sdk_tools.sh --sync -C ~/proj/rk356x_sdk-linux5.10

2.1.2. Sync Code

Execute the following command to synchronize the code:

# Enter the SDK root directory
cd ~/proj/rk356x_sdk-linux5.10

# Sync
.repo/repo/repo sync -c --no-tags
.repo/repo/repo start firefly --all

You can use the following command to update the SDK later:

.repo/repo/repo sync -c --no-tags

2.1.3. Directory

.
├── app
├── buildroot														# Buildroot root filesystem build directory
├── build.sh -> device/rockchip/common/build.sh					# Compile script
├── device															# Compile related configuration files
├── docs															# Documentation
├── envsetup.sh -> buildroot/build/envsetup.sh
├── external
├── kernel															# Kernel
├── Makefile -> buildroot/build/Makefile
├── prebuilts														# Cross compilation toolchain
├── rkbin
├── tools															# Tools directory
└── u-boot															# U-Boot

2.1.4. Install dependencies

  • Method 1:

Install directly on PC:

sudo apt-get install repo git ssh make gcc libssl-dev liblz4-tool \
expect g++ patchelf chrpath gawk texinfo chrpath diffstat binfmt-support \
qemu-user-static live-build bison flex fakeroot cmake \
unzip device-tree-compiler python-pip ncurses-dev python-pyelftools
  • Method 2: Use Docker

Use dockerfile to create a container, build SDK in the container, it will perfectly solve environment problems and isolate with host environments.

First install docker in the host PC, you can refer to Docker instructions

Create an empty folder as docker work dir, like ~/docker/, then touch a dockerfile with contents:

FROM ubuntu:18.04
MAINTAINER firefly "service@t-firefly.com"

ENV DEBIAN_FRONTEND=noninteractive

RUN apt update

RUN apt install -y build-essential crossbuild-essential-arm64 \
	bash-completion vim sudo locales time rsync bc python

RUN apt install -y repo git ssh libssl-dev liblz4-tool lib32stdc++6 \
	expect patchelf chrpath gawk texinfo diffstat binfmt-support \
	qemu-user-static live-build bison flex fakeroot cmake \
	unzip device-tree-compiler python-pip ncurses-dev python-pyelftools \
	subversion asciidoc w3m dblatex graphviz python-matplotlib cpio \
	libparse-yapp-perl default-jre patchutils swig expect-dev u-boot-tools

RUN apt update && apt install -y -f

# language support
RUN locale-gen en_US.UTF-8
ENV LANG en_US.UTF-8

# switch to a no-root user
RUN useradd -c 'firefly user' -m -d /home/firefly -s /bin/bash firefly
RUN sed -i -e '/\%sudo/ c \%sudo ALL=(ALL) NOPASSWD: ALL' /etc/sudoers
RUN usermod -a -G sudo firefly

USER firefly
WORKDIR /home/firefly

Create image

cd ~/docker
docker build -t sdkcompiler .
# sdkcompiler is image name, you can change it, notice that there's a '.' at the end of cmd
# This process takes a while, please wait

Then create a container

# Here we mount host SDK location into the container, so that you can access SDK inside container
# source= is host SDK location; target= is a folder inside container, must be an empty folder
# ubuntu18 is container name, firefly is container's hostname, you can change them
# sdkcompiler is the image created in last step
docker run --privileged --mount type=bind,source=/home/fierfly/proj,target=/home/firefly/proj --name="ubuntu18" -h firefly -it sdkcompiler

Now you can build SDK inside the container.

How to quit container and how to reopen:

# Execute "exit" inside container will quit and close it

# See all containers (include exited ones)
docker ps -a

# Start an exited container and attach it
docker start ubuntu18 # container name
docker attach ubuntu18

2.2. Compile Ubuntu firmware

This chapter introduces the compilation process of Ubuntu firmware. It is recommended to develop under Ubuntu 18.04 system environment. If you use other system versions, you may need to adjust the compilation environment accordingly.

2.2.1. A brief introduction to Ubuntu firmware

What is Ubuntu Minimal ?

What is Ubuntu Desktop ?

2.2.2. Build Linux-SDK

2.2.2.1. Precompile Configuration

There are configuration files for different board in device/rockchip/rk3566_rk3568/.

Return to SDK root directory to select the configuration file:

./build.sh firefly_rk3568_itx-3568q_ubuntu_defconfig

The configuration file will be connected to output/defconfig, check the file to verify whether the configuration is successful.

Configruation content:

# prebuilt rootfs
PREBUILT_ROOTFS_IMG="prebuilt_rootfs/rk356x_ubuntu_rootfs.img"
# UART for bluetooth
RK_WIFIBT_TTY="ttyS8"
# kernel defconfig
RK_KERNEL_CFG="firefly_linux_defconfig"
# device tree name
RK_KERNEL_DTS_NAME="rk3568j-firefly-itxq"
# ramdisk image
RK_RAMDISK_IMG="ramdisk.img"
# image tree source for boot partition image
RK_BOOT_FIT_ITS="bootramdisk.its"
# prebuilt recovery image
RK_RECOVERY_RAMDISK="rk356x-recovery-arm64.cpio.gz"
# parameter
RK_PARAMETER="parameter-ubuntu-fit.txt"
# use FIT image
RK_USE_FIT_IMG=y
# use extlinux way to load kernel
USE_EXTBOOT=y

2.2.2.2. Download Ubuntu filesystem

# For example, the archive you download is Ubuntu20.04-xxx_RK3568_KERNEL-5.10_xxx.7z
7z x Ubuntu20.04-xxx_RK3568_KERNEL-5.10_xxx.7z
  • Move filesystem to prebuilt_rootfs/

mkdir prebuilt_rootfs
# For example, after unzip, the filesystem image is Ubuntu20.04-xxx_RK3568_KERNEL-5.10_xxx.img
mv Ubuntu20.04-xxx_RK3568_KERNEL-5.10_xxx.img prebuilt_rootfs/
ln -sf Ubuntu20.04-xxx_RK3568_KERNEL-5.10_xxx.img rk356x_ubuntu_rootfs.img

2.2.2.3. Automatic compilation

The automatic compilation will perform all compilation and packaging operations to generate RK firmware.

./build.sh all

Firmware will be saved to the directory output/update/.

2.2.2.4. Partial compilation

  • u-boot

./build.sh uboot

Output image is u-boot/uboot.img

  • kernel

Notice:Firefly kernel does not come with all kernel features, need extra kernel features please refer to Kernel

./build.sh extboot

Output image is kernel/extboot.img

2.2.2.5. Pack the firmware

./build.sh updateimg

Pack the firmware, the firmware will be saved to the directory rockdev/pack/.

2.2.3. Partition table

2.2.3.1. parameter

The parameter.txt file contains the partition information of the firmware. Take parameter-ubuntu-fit.txt as an example:

path: device/rockchip/rk3566_rk3568/parameter-ubuntu-fit.txt

FIRMWARE_VER: 1.0
MACHINE_MODEL: RK3568
MACHINE_ID: 007
MANUFACTURER: RK3568
MAGIC: 0x5041524B
ATAG: 0x00200800
MACHINE: 0xffffffff
CHECK_MASK: 0x80
PWR_HLD: 0,0,A,0,1
TYPE: GPT
GROW_ALIGN: 0
CMDLINE: mtdparts=rk29xxnand:0x00002000@0x00004000(uboot),0x00002000@0x00006000(misc),0x00040000@0x00008000(boot:bootable),0x00020000@0x00048000(recovery),0x00010000@0x00068000(backup),0x00c00000@0x00078000(rootfs),-@0x00c78000(userdata:grow)
uuid:rootfs=614e0000-0000-4b53-8000-1d28000054a9

The CMDLINE attribute is where we are concerned. Take uboot as an example. In 0x00002000@0x00004000(uboot), 0x00004000 is the starting position of the uboot partition, 0x00002000 is the size of the partition, and so on. The unit is block, each block is 512 Byte.

2.3. Compile Buildroot firmware

This chapter introduces the compilation process of Buildroot firmware. It is recommended to develop in the Ubuntu 18.04 system environment. If you use other system versions, you may need to adjust the compilation environment accordingly.

2.3.1. Compile SDK

2.3.1.1. Configuration before compilation

In the device/rockchip/rk3566_rk3568/ directory, there are configuration files of different board types.

Return to SDK root directory to select the configuration file:

./build.sh firefly_rk3568_itx-3568q_buildroot_defconfig

The configuration file will be linked to output/defconfig, check the file to verify whether the configuration is successful.

Related configuration introduction:

# device tree name
RK_KERNEL_DTS_NAME="rk3568j-firefly-itxq"
# kernel defconfig
RK_KERNEL_CFG="firefly_linux_defconfig"
# use FIT image
RK_USE_FIT_IMG=y
# UART for bluetooth
RK_WIFIBT_TTY="ttyS8"
# parameter
RK_PARAMETER="parameter-buildroot-fit.txt"
# image tree source of boot partition image
RK_BOOT_FIT_ITS="bootramdisk.its"
# ramdisk image
RK_RAMDISK_IMG="ramdisk.img"
# use extlinux way to load kernel
USE_EXTBOOT=y

2.3.1.2. Automatic compilation

Fully automatic compilation will perform all compilation and packaging operations to generate complete firmware.

./build.sh all

Firmware will be saved to output/update/ directory

2.3.1.3. Partial compilation

  • Compile u-boot

./build.sh uboot

Output image is u-boot/uboot.img

  • Compile kernel

Notice:Firefly kernel does not come with all kernel features, need extra kernel features please refer to Kernel

./build.sh extboot

Output image is kernel/extboot.img

  • Compile recovery

./build.sh recovery

Outputs are under output/recovery

  • Compile Buildroot root filesystem

./build.sh buildroot

# Note: Make sure to compile the Buildroot root filesystem as a normal user to avoid unnecessary errors.

Compiling the Buildroot root filesystem will generate a compilation output directory in buildroot/output

2.3.1.4. Package the firmware

./build.sh updateimg

Pack the firmware, the generated complete firmware will be saved to the output/update/ directory.

2.3.2. Partition description

2.3.2.1. parameter partition table

The parameter.txt file contains the partition information of the firmware. Take parameter-buildroot-fit.txt as an example:

Path: device/rockchip/rk3566_rk3568/parameter-buildroot-fit.txt

FIRMWARE_VER: 1.0
MACHINE_MODEL: RK3568
MACHINE_ID: 007
MANUFACTURER: RK3568
MAGIC: 0x5041524B
ATAG: 0x00200800
MACHINE: 0xffffffff
CHECK_MASK: 0x80
PWR_HLD: 0,0,A,0,1
TYPE: GPT
GROW_ALIGN: 0
CMDLINE: mtdparts=:0x00002000@0x00004000(uboot),0x00002000@0x00006000(misc),0x00040000@0x00008000(boot:bootable),0x00020000@0x00048000(recovery),0x00010000@0x00068000(backup),0x00040000@0x00078000(oem),0x00c00000@0x000b8000(rootfs),-@0x00cb8000(userdata:grow)
uuid:rootfs=614e0000-0000-4b53-8000-1d28000054a9

The CMDLINE attribute is our focus. Taking uboot as an example, 0x00004000 in 0x00002000@0x00004000(uboot) is the starting position of the uboot partition, 0x00002000 is the size of the partition, and so on. The unit is block, each block is 512 Byte.