How to find KCONFIG options

How do I find and enable a specific kernel or menuconfig option?

Problem Description

If I know the name of a specific kernel config option, how do I find it in the menuconfig, and find out its dependencies?

Background

The Linux kernel menu configuration system, also used to drive system and application configuration in PetaLinux SDK, defines configuration variables with names such as

CONFIG_OPTIONNAME

If there is a specific option you wish to enable, it can be difficult locating it in the configuration menu structure, and this is made more difficult if that option is has certain dependencies which might not have been met.

Resolution

Menuconfig has a simple way of solving this problem.

Once inside menuconfig (after running either 'petalinux-config-kernel' or 'petalinux-config-apps'), you can press '/', then type part of the config var you are looking for, without the CONFIG_ prefix.

For example, to find CONFIG_PROC_DEVICETREE option in the Linux kernel menuconfiguration, you would open the kernel config menu, and type

/DEVICETREE

then press <enter>.

The display will show the following:

Symbol: PROC_DEVICETREE [=n]
Type  : boolean
Prompt: Support for device tree in /proc
Defined at drivers/of/Kconfig:10
Depends on: OF [=y] && PROC_FS [=y] && !SPARC
Location:
  -> Device Drivers
    -> Device Tree and Open Firmware support

Now you can see the dependencies for that option and where to find it in the menu structure.