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Configuration of Uboot and Kernel Options

In software development, it is often necessary to configure the functional options of Uboot and Kernel. This chapter introduces several commonly used configuration methods for users' reference.

Configuration of Uboot Options​

Note

The following instructions are provided with the example of modifying the xj3_ubuntu_nand_defconfig configuration file.

The specific configuration file used by Uboot can be found in the bootloader/device/.board_config.mk board-level configuration file after executing ./xbuild.sh lunch, in the HR_UBOOT_CONFIG_FILE variable.

First, enter the uboot directory and execute make ARCH=arm64 xj3_ubuntu_nand_defconfig. Because the make command will first execute the Makefile file in the top-level directory. The targets ending with config have a common entry:

%config: scripts_basic outputmakefile FORCE
        $(Q)$(MAKE) $(build)=scripts/kconfig $@

The expanded command is:

make -f ./scripts/Makefile.build obj=scripts/kconfig xj3_ubuntu_nand_defconfig

After executing this command, a .config file will be generated in the root directory of the Uboot source code.

make ARCH=arm64 xj3_ubuntu_nand_defconfig

  HOSTCC  scripts/basic/fixdep
  HOSTCC  scripts/kconfig/conf.o
  YACC    scripts/kconfig/zconf.tab.c
  LEX     scripts/kconfig/zconf.lex.c
  HOSTCC  scripts/kconfig/zconf.tab.o
  HOSTLD  scripts/kconfig/conf
#
# configuration written to .config
#

Then, you can execute make ARCH=arm64 menuconfig to open the graphical configuration interface for configuring Uboot options.

image-20220518111319607After completing the configuration in the menuconfig interface, select "Exit" and choose "Yes" or "No" to save the modifications to the .config file according to the prompt.

image-20220518111506018

After saving the configuration, execute the command diff .config configs/xj3_ubuntu_nand_defconfig to compare the differences and confirm whether the modifications meet expectations.

If the modifications are correct, execute cp .config configs/xj3_ubuntu_nand_defconfig to replace the default configuration file.

Configure Kernel Options​

Note

The following instructions are based on modifying the xj3_perf_ubuntu_defconfig configuration file.

The specific configuration file used by the kernel can be found in the kernel_config_file variable in the mk_kernel.sh script.

Configuring the kernel through menuconfig is similar to configuring U-Boot. Follow these steps to configure the kernel options.

  • Use xj3_perf_ubuntu_defconfig to generate .config. If the source code has been fully compiled, the .config file will already be configured.
make ARCH=arm64 xj3_perf_ubuntu_defconfig
  • Execute the following command to modify the configuration.
make ARCH=arm64 menuconfig
  • After making modifications, you can see the differences between the modified and original configurations.
diff .config arch/arm64/configs/xj3_perf_ubuntu_defconfig
  • Overwrite xj3_perf_ubuntu_defconfig with the new configuration.
cp .config arch/arm64/configs/xj3_perf_ubuntu_defconfig