Compile the Buildroot firmware

This chapter introduces the compilation process of Buildroot firmware. It is recommended to develop in the Ubuntu 16.04 system environment. If you use other system versions, you may need to adjust the compilation environment accordingly.

Download Firefly_Linux_SDK sub-volume compressed package

Since the Firefly_Linux_SDK source code package is relatively large, some users’ computers do not support files above 4G or the network transmission of a single file is slow, so we use the method of sub-volume compression to package the SDK. Users can obtain the Firefly_Linux_SDK source code package in the following ways:Firefly_Linux_SDK Source

After the download is complete, verify the MD5 code:

$ md5sum rk3399_linux_release_v2.5.1_20210301_split_dir/*firefly_split*
2cf71e64d35eb8083a4a0fc30c256484  rk3399_linux_release_v2.5.1_20210301_split_dir/rk3399_linux_release_v2.5.1_20210301_firefly_split.file0
f0e9292b3816a8f1ce0eb1eeb483ad56  rk3399_linux_release_v2.5.1_20210301_split_dir/rk3399_linux_release_v2.5.1_20210301_firefly_split.file1
c6aaa5d761d0e7917bea1cb78a0e7229  rk3399_linux_release_v2.5.1_20210301_split_dir/rk3399_linux_release_v2.5.1_20210301_firefly_split.file2
16022cc729d06a28fec30ac52885d91c  rk3399_linux_release_v2.5.1_20210301_split_dir/rk3399_linux_release_v2.5.1_20210301_firefly_split.file3
565426354c01d56c7d48479dd7f3c35b  rk3399_linux_release_v2.5.1_20210301_split_dir/rk3399_linux_release_v2.5.1_20210301_firefly_split.file4
313d311f1705fbfb7bfc45b7937ecf24  rk3399_linux_release_v2.5.1_20210301_split_dir/rk3399_linux_release_v2.5.1_20210301_firefly_split.file5

Unpack Firefly_Linux_SDK sub-volume compressed package

After confirming that it is correct, you can unpack:

cat rk3399_linux_release_v2.5.1_20210301_split_dir/*firefly_split* | tar -xzv

#This SDK folder contains a .repo directory, after decompression, perform the following operations in the current directory
cd rk3399_linux_release_v2.5.1_20210301
ls -al

.repo/repo/repo sync -l
.repo/repo/repo sync -c --no-tags
.repo/repo/repo start firefly --all

Update Firefly_Linux_SDK

You can use the following command to update the SDK later

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

Directory Structure

$ tree -L 1
.
├── app
├── buildroot # Buildroot root file system build directory
├── build.sh -> device/rockchip/common/build.sh # compile script
├── debian # Debian root file system compilation directory
├── device # Compile related configuration files
├── distro
├── docs # Documentation
├── envsetup.sh -> buildroot/build/envsetup.sh
├── external
├── kernel
├── Makefile -> buildroot/build/Makefile
├── mkfirmware.sh -> device/rockchip/common/mkfirmware.sh # link script
├── prebuilts # Cross compilation tool chain
├── rkbin
├── rkflash.sh -> device/rockchip/common/rkflash.sh # Flash script
├── tools # Tools directory
├── u-boot
└── yocto

Build a compilation environment

sudo apt-get install expect-dev repo git-core gitk git-gui gcc-arm-linux-gnueabihf u-boot-tools device-tree-compiler \
gcc-aarch64-linux-gnu mtools parted libudev-dev libusb-1.0-0-dev python-linaro-image-tools \
linaro-image-tools autoconf autotools-dev libsigsegv2 m4 intltool libdrm-dev curl sed make \
binutils build-essential gcc g++ bash patch gzip bzip2 perl tar cpio python unzip rsync file bc wget \
libncurses5 libqt4-dev libglib2.0-dev libgtk2.0-dev libglade2-dev cvs git mercurial rsync openssh-client \
subversion asciidoc w3m dblatex graphviz python-matplotlib libc6:i386 libssl-dev texinfo \
liblz4-tool genext2fs lib32stdc++6 expect

Compile SDK

Configuration before compilation

In the device/rockchip/rk3399/ directory, there are configuration files of different board types, select the configuration file:

./build.sh roc-rk3399-pc-plus-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=roc-rk3399-pc_defconfig # u-boot configuration file
# Kernel defconfig
export RK_KERNEL_DEFCONFIG=firefly_linux_defconfig # kernel configuration file
# Kernel dts
export RK_KERNEL_DTS=rk3399-roc-pc-plus # dts file
# Buildroot config
export RK_CFG_BUILDROOT=rockchip_rk3399 # Buildroot configuration
# Recovery config
export RK_CFG_RECOVERY=rockchip_rk3399_recovery # recovery configuration
# parameter for GPT table
export RK_PARAMETER=parameter-buildroot.txt # Partition table
# rootfs image path
export RK_ROOTFS_IMG=buildroot/output/$RK_CFG_BUILDROOT/images/rootfs.$RK_ROOTFS_TYPE # root file system path

Partial compilation

  • Compile u-boot

./build.sh uboot
  • Compile kernel

./build.sh kernel
  • Compile recovery

./build.sh recovery
  • Compile Buildroot root file system

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

./build.sh buildroot

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

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

Automatic compilation

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

./build.sh

Partition description

parameter partition table

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

Path: device/rockchip/rk3288/parameter.txt

FIRMWARE_VER: 8.1
MACHINE_MODEL: RK3399
MACHINE_ID: 007
MANUFACTURER: RK3399
MAGIC: 0x5041524B
ATAG: 0x00200800
MACHINE: 3399
CHECK_MASK: 0x80
PWR_HLD: 0,0,A,0,1
TYPE: GPT
CMDLINE: mtdparts=rk29xxnand:0x00002000@0x00004000(uboot),0x00002000@0x00006000(trust),0x00002000@0x00008000(misc),0x00010000@0x0000a000(boot),0x00010000@0x0001a000(recovery),0x00010000x@0x0000@2a000) 0x0003a000(oem),0x00c00000@0x0005a000(rootfs),-@0x00c5a000(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.

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/rk3399-package-file

# NAME Relative path
#
#HWDEF HWDEF
package-file package-file
bootloader Image/MiniLoaderAll.bin
parameter Image/parameter.txt
trust Image/trust.img
uboot Image/uboot.img
misc Image/misc.img
#resource Image/resource.img
#kernel Image/kernel.img
boot Image/boot.img
recovery Image/recovery.img
rootfs Image/rootfs.img
oem Image/oem.img
userdata:grow Image/userdata.img
backup RESERVED
#update-script update-script
#recover-script recover-script