1. Compile Linux firmware

1.1. 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.

1.1.1. 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:

mkdir ~/proj/rk356x_linux_release_v1.3.0b_20221213/
cd ~/proj/rk356x_linux_release_v1.3.0b_20221213/

## Full SDK
repo init --no-clone-bundle --repo-url https://gitlab.com/firefly-linux/git-repo.git -u https://gitlab.com/firefly-linux/manifests.git -b master -m rk356x_linux_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 -u https://gitlab.com/firefly-linux/manifests.git -b master -m rk356x_linux_bsp_release.xml

  • Method Two

Download Firefly_Linux_SDK sub-volume compressed package: Firefly_Linux_SDK Source

After downloading, verify the MD5 code:

$ md5sum rk356x_linux_release_v1.3.0b_20221213_split_dir/*firefly_split*
409b81a9ed3bb9a7d6af91223836cad5  rk356x_linux_release_v1.3.0b_20221213_split_dir/rk356x_linux_release_v1.3.0b_20221213_firefly_split.file00
75cef82f2bf91052a7d3c6f0b8405a89  rk356x_linux_release_v1.3.0b_20221213_split_dir/rk356x_linux_release_v1.3.0b_20221213_firefly_split.file01
6f20f62e9652f8f999692587a2ac4b79  rk356x_linux_release_v1.3.0b_20221213_split_dir/rk356x_linux_release_v1.3.0b_20221213_firefly_split.file02
113acbbcd18d3abe0552ef296e983a3f  rk356x_linux_release_v1.3.0b_20221213_split_dir/rk356x_linux_release_v1.3.0b_20221213_firefly_split.file03
624c88a4da2eaa4a48f380783b126d00  rk356x_linux_release_v1.3.0b_20221213_split_dir/rk356x_linux_release_v1.3.0b_20221213_firefly_split.file04
1cf861afb0b36c9ebcf26a7d6effb260  rk356x_linux_release_v1.3.0b_20221213_split_dir/rk356x_linux_release_v1.3.0b_20221213_firefly_split.file05
3009e46fc14481e77fe7ec143e217de4  rk356x_linux_release_v1.3.0b_20221213_split_dir/rk356x_linux_release_v1.3.0b_20221213_firefly_split.file06
5e1cc90b99e34f20b75fb506d3e9bcd7  rk356x_linux_release_v1.3.0b_20221213_split_dir/rk356x_linux_release_v1.3.0b_20221213_firefly_split.file07
1a512fa7c9e2fd1a0781f8d40e228402  rk356x_linux_release_v1.3.0b_20221213_split_dir/rk356x_linux_release_v1.3.0b_20221213_firefly_split.file08

After confirming that it is correct, you can unzip:

# unzip
mkdir ~/proj/
cd ~/proj/
cat path/to/rk356x_linux_release_v1.3.0b_20221213_split_dir/*firefly_split* | tar -xzv

# export data
.repo/repo/repo sync -l

1.1.2. Sync Code

Execute the following command to synchronize the code:

# Enter the SDK root directory
cd ~/proj/rk356x_linux_release_v1.3.0b_20221213/

# 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

1.1.3. Directory

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

1.1.4. 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

1.2. 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.

1.2.1. A brief introduction to Ubuntu firmware

What is Ubuntu Minimal firmware?

What is Ubuntu Desktop firmware?

1.2.2. Build Linux-SDK

1.2.2.1. Precompile Configuration

There are configuration files for different board in device/rockchip/rk356x/.

Return to SDK root directory to select the configuration file:

./build.sh aio-3568j-ubuntu.mk

The configuration file will be connected to device/rockchip/.BoardConfig.mk, check the file to verify whether the configuration is successful.

Configruation content:

# Target arch
export RK_ARCH=arm64 # 64-bit ARM
# Uboot defconfig
export RK_UBOOT_DEFCONFIG=firefly_rk3568 # u-boot configuration
# Kernel defconfig
export RK_KERNEL_DEFCONFIG=firefly_linux_defconfig # kernel configuration
# Kernel dts
export RK_KERNEL_DTS=firefly-rk3568-aioj # dts file
# parameter for GPT table
export RK_PARAMETER=parameter-ubuntu-fit.txt # partition table
# rootfs image path
export RK_ROOTFS_IMG=ubuntu_rootfs/rk356x_ubuntu_rootfs.img # filesystem path

1.2.2.2. Select Accessories to Compile

Under device/rockchip/rk356x/ , in addition to aio-3568j-ubuntu.mk, there are other configuration files that come with different accessories

The name of the configuration file indicates the screen and camera used. If the screen is not specified, the default HDMI display is used. If the camera is not specified, the default single camera is used

# For example:
xxxx-ubuntu.mk                      # Use HDMI + single-camera
xxxx-2cam-ubuntu.mk                 # Use HDMI + dual-camera
xxxx-mipi-ubuntu.mk                 # Use mipi + single-camera
xxxx-mipi-2cam-ubuntu.mk            # Use mipi + dual-camera
xxxx-tf-hdmi-mipi-rk628-ubuntu.mk   # Use HDMI + HDMI TO MIPI_CSI(RK628D)

Note:The AIO-3568J hardware version must be V1.3 and later to support the use of HDMI-TO-MIPI_CSI drive board.

Chose the configuration file you like, execute build.sh to make it effective:

# For example:
./build.sh xxxx-mipi-2cam-ubuntu.mk

1.2.2.3. Download Ubuntu filesystem

7z x ubuntu-aarch64-rootfs.7z

  • Move filesystem to ubuntu_rootfs/

mkdir ubuntu_rootfs
mv ubuntu-aarch64-rootfs.img ubuntu_rootfs/rk356x_ubuntu_rootfs.img

1.2.2.4. Automatic compilation

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

./build.sh

1.2.2.5. Partial compilation

  • u-boot

./build.sh uboot

  • kernel

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

./build.sh kernel

Notice：Linux SDK v1.2.4a and later using extboot, please use ./build.sh extboot to build kernel

The output file is SDK/kernel/extboot.img, use it instead of boot.img

How to check SDK version:

  1. The version format is vx.x.xx, eg: v1.2.4a

  2. Firmware filename has SDK version(…_vx.x.xx_date.img)

  3. Buildroot usecat /etc/versionto get version(rk356x_linux_release_date_vx.x.xx.xml)

  4. Ubuntu useffgo versionto get(rk356x_linux_release_date_vx.x.xx.xml)

  5. In SDK check the link:ls -l .repo/manifests/rk356x_linux_release.xml

  6. If you can’t get version by methods above, that means you are using old version, no support for extboot

Do not burn extboot.img into old version firmware!

Besides, extboot ubuntu support update kernel by deb package, please see Ubuntu Manual

  • recovery

./build.sh recovery

1.2.2.7. Pack the firmware

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

1.2.2.7.1. RK firmware

RK firmware is the firmware packaged in Rockchip’s proprietary format, and can be flashed to eMMC or SD card with the tools provided by Rockchip (Note: If there is no special instruction, the firmware mentioned on WIKI defaults to RK firmware) .

# Pack RK firmware
./build.sh updateimg
1.2.2.7.2. RAW firmware

RAW firmware is a kind of firmware that can be flashed to the storage device in a bit-by-bit copy mode, and is the original image of the storage device. Different from the RK firmware, currently it only supports flashing to SD card to boot with Etcher tool.

Etcher official download link

# Package RAW firmware
./build.sh rawimg

1.2.3. Partition table

1.2.3.1. parameter

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

path: device/rockchip/rk356x/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
CMDLINE: mtdparts=rk29xxnand:0x00002000@0x00004000(uboot),0x00002000@0x00006000(misc),0x00010000@0x00008000(boot),0x00010000@0x00018000(recovery),0x00010000@0x00028000(backup),0x00c00000@0x00038000(rootfs),-@0x00c38000(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.

1.2.3.2. package-file

The package-file is used to determine the required partition image and image path when packaging the firmware, and it needs to be consistent with the parameter.txt.

path: tools/linux/Linux_Pack_Firmware/rockdev/rk356x-ubuntu-package-file

# NAME          Relative path
#
#HWDEF          HWDEF
package-file    package-file
bootloader      Image/MiniLoaderAll.bin
parameter       Image/parameter.txt
uboot           Image/uboot.img
misc            Image/misc.img
boot            Image/boot.img
recovery        Image/recovery.img
rootfs          Image/rootfs.img
userdata        RESERVED
backup          RESERVED

1.3. Compile Debian Firmware

This chapter introduces the compilation process of Debian 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.

1.3.1. Compile

The only difference between the compilation method of Debian firmware and Ubuntu is the use of different filesystems, other steps including configuration files are exactly the same.

So please refer to Compile Ubuntu firmware

Now only introduce the difference: replacing of filesystem

1.3.1.1. Download Debian filesystem

7z x Debian10-xxxx_RK3568_xxxx.7z

  • Put rootfs under ubuntu_rootfs/

mkdir ubuntu_rootfs
mv Debian10-xxxx_RK3568_xxxx.img ubuntu_rootfs/

  • Create a symbolic link to rk356x_ubuntu_rootfs.img

cd ubuntu_rootfs
ln -sf Debian10-xxxx_RK3568_xxxx.img rk356x_ubuntu_rootfs.img

Then follow the normal steps just like you are compiling ubuntu firmware

1.4. 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.

1.4.1. Compile SDK

1.4.1.1. Configuration before compilation

In the device/rockchip/rk356x/ directory, there are configuration files of different board types.

Return to SDK root directory to select the configuration file:

./build.sh aio-3568j-buildroot.mk

The configuration file will be linked to device/rockchip/.BoardConfig.mk, check the file to verify whether the configuration is successful.

Related configuration introduction:

# Target arch
export RK_ARCH=arm64 # 64-bit ARM architecture
# Uboot defconfig
export RK_UBOOT_DEFCONFIG=firefly_rk3568 # u-boot configuration file
# Kernel defconfig
export RK_KERNEL_DEFCONFIG=firefly_linux_defconfig # kernel configuration file
# Kernel dts
export RK_KERNEL_DTS=firefly-rk3568-aioj # dts file
# Buildroot config
export RK_CFG_BUILDROOT=rockchip_rk3568 # Buildroot configuration
# Recovery config
export RK_CFG_RECOVERY=rockchip_rk356x_recovery # recovery configuration
# parameter for GPT table
export RK_PARAMETER=parameter-buildroot-fit.txt # Partition table
# rootfs image path
export RK_ROOTFS_IMG=rockdev/rootfs.${RK_ROOTFS_TYPE} # root filesystem path

1.4.1.2. Select Accessories to Compile

Under device/rockchip/rk356x/ , in addition to aio-3568j-buildroot.mk, there are other configuration files that come with different accessories

The name of the configuration file indicates the screen and camera used. If the screen is not specified, the default HDMI display is used. If the camera is not specified, the default single camera is used

# For example:
xxxx-buildroot.mk              # Use HDMI + single-camera
xxxx-2cam-buildroot.mk         # Use HDMI + dual-camera
xxxx-mipi-buildroot.mk         # Use mipi + single-camera
xxxx-mipi-2cam-buildroot.mk    # Use mipi + dual-camera

Chose the configuration file you like, execute build.sh to make it effective:

# For example:
./build.sh xxxx-mipi-2cam-buildroot.mk

1.4.1.3. Automatic compilation

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

./build.sh

1.4.1.4. Partial compilation

  • Compile u-boot

./build.sh uboot

  • Compile kernel

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

./build.sh kernel

  • Compile recovery

./build.sh recovery

  • Compile Buildroot root filesystem

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

./build.sh buildroot

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

1.4.1.5. Package the firmware

Update each part of the mirror link to the rockdev/ directory:

./mkfirmware.sh

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

./build.sh updateimg

1.4.2. Partition description

1.4.2.1. 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/rk356x/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
CMDLINE: mtdparts=rk29xxnand:0x00002000@0x00004000(uboot),0x00002000@0x00006000(misc),0x00010000@0x00008000(boot),0x00010000@0x00018000(recovery),0x00010000@0x00028000(backup),0x00040000@0x00038000(oem),0x00c00000@0x00078000(rootfs),-@0x00c78000(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.

1.4.2.2. package-file

The package-file file is used to determine the required partition image and image path when packaging the firmware, and it needs to be consistent with the parameter.txt file.

Path: tools/linux/Linux_Pack_Firmware/rockdev/rk356x-package-file

package-file    package-file
bootloader      Image/MiniLoaderAll.bin
parameter       Image/parameter.txt
uboot           Image/uboot.img
misc            Image/misc.img
boot            Image/boot.img
recovery        Image/recovery.img
rootfs          Image/rootfs.img
oem             Image/oem.img
userdata        Image/userdata.img
backup          RESERVED