2. Linux SDK Configuration introduction

2.1. Directory

$ tree -L 1
.
├── 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
├── 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

2.2. Introduction to configuration files

In the device/rockchip/rk3588/ directory, there are configuration files (xxxx.mk) for different board types, which are used to manage the compilation configuration of each project of the SDK. The relevant configuration introduction:

# Target arch
export RK_ARCH=arm64
# Uboot defconfig
export RK_UBOOT_DEFCONFIG=xxxx_defconfig
# Kernel defconfig
export RK_KERNEL_DEFCONFIG=xxxx_defconfig
# Kernel defconfig fragment
export RK_KERNEL_DEFCONFIG_FRAGMENT=xxxx.config
# Kernel dts
export RK_KERNEL_DTS=roc-rk3588s-pc.dts
# parameter for GPT table
export RK_PARAMETER=parameter-xxxx.txt
# rootfs image path
export RK_ROOTFS_IMG=ubuntu_rootfs/rootfs.img

2.3. Partition table

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/rk3588/parameter-ubuntu-fit.txt

FIRMWARE_VER: 1.0
MACHINE_MODEL: RK3588
MACHINE_ID: 007
MANUFACTURER: RK3588
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),0x00020000@0x00008000(boot:bootable),0x00040000@0x00028000(recovery),0x00010000@0x00068000(backup),0x00c00000@0x00078000(rootfs),0x00040000@0x00c78000(oem),-@0x00cb8000(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.

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/rk3588-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