How to create a defconfig file from a .config?

linux-kernel embedded-linux kbuild archlinux-arm
user3693586 picture user3693586 · Jan 12, 2015 · Viewed 44.3k times · Source

I have done make menuconfig for a board defconfig and modified few configurations. When I select save, a new .config was created in the Kernel top directory.

I want to create new defconfig for this .config file created.

Can I copy the .config as a new defconfig and copy to arch/arm/configs/?

$ cp .config arch/arm/configs/board_new_defconfig

Answer

0andriy picture 0andriy · Jan 13, 2015

I think you have to do just one command and use the created file as you want to.

% make savedefconfig 
% cp defconfig arch/arm/configs/my_cool_defconfig

To get all possible targets just run

% make help

As noted by Adam Miller followed by Jeremy, users of Buildroot distribution can use wrappers for that purpose, i.e. (per Buildroot manual, section 8.1):

  • linux-savedefconfig for linux
  • barebox-savedefconfig for barebox bootloader
  • uboot-savedefconfig for U-Boot bootloader

make savedefconfig minimizes the generated defconfig skipping redundant configs that are implied by others.

Related questions

Image vs zImage vs uImage

What is the difference between them? I know that u-boot needs a kernel in uImage format. The system I use first boots from stage 1 loader and then it calls u-boot. I want to discard u-boot and directly boot from stage 1 …

Read More
How to write a simple Linux device driver?

I need to write an SPI Linux character device driver for omap4 from scratch. I know some basics of writing device drivers. But, I don't know how to start writing platform specific device driver from scratch. I've written some basic …

Read More
How to compile dts Linux device tree source files to dtb?

I have a device tree file (.dts) and I want to compile the file for my powerpc based board. How can I do it on my machine, which is not powerpc based?? Can I do it with the DTC installed …

Read More