Adding an entry to the Linux Kernel .config file

Question

How can I manually add the line CONFIG_XILINX_FIXED_DEVTREE_ADDR=y to the linux config file? It keeps getting overwritten when I build the kernel

Don't add it manually. Use `make menuconfig`. See: http://tldp.org/HOWTO/SCSI-2.4-HOWTO/kconfig.html — Peter L., Feb 18 '16 at 21:39

score 2 · Answer 1 · answered Feb 19 '16 at 05:45

2

You can build by make CONFIG_XILINX_FIXED_DEVTREE_ADDR=y without adding it into .config. But if you gonna add it to .config, you should use make menuconfig to select it and save it into .config.

answered Feb 19 '16 at 05:45

Youngdo Lee

158
6

Thanks for your help, I'm at the menuconfig right now, where exactly would I place this entry at? – Jon Sherman Feb 19 '16 at 21:39
@YoungdoLee, Not necessary. You may add manually entire Kconfig tree which leads to certain option be enabled. – 0andriy Feb 19 '16 at 22:44
@JonSherman I don't know where it is, because I don't have your kernel. But you can find where your config is by pressing `/` in menuconfig and then typing the keyword. In your case `XILINX_FIXED_DEVTREE_ADDR`. The menuconfig console will show where it is. – Youngdo Lee Feb 22 '16 at 01:01
@AndyShevchenko Yes. But IMHO, if I am a user or builder(not developer for that kernel tree), i think using menuconfig is better than editing .config or Kconfig or *_defconfig. In this backound, I recommended above method. – Youngdo Lee Feb 22 '16 at 01:06
@YoungdoLee, I tried searching for it, and there's no matching results. The XILINX_FIXED_DEVTREE_ADDR is not an entry in the .config file, I'm trying to add it though. – Jon Sherman Feb 24 '16 at 22:07

score 0 · Answer 2 · answered Apr 29 '22 at 18:18

If the config variable you're trying to add is new (as in, not in .config at all and not showing up in make menuconfig), then you should add it to the relevant Kconfig file. For instance, if you look at fs/proc/Kconfig, you can see how different proc config options are laid out. Follow their example and add your config variable, its variable type, the default, and its description. Then you should see it in make menuconfig.

Here's an example of a config variable definition in fs/proc/Kconfig:

config PROC_VMCORE
    bool "/proc/vmcore support"
    depends on PROC_FS && CRASH_DUMP
    default y
    help
      Exports the dump image of crashed kernel in ELF format.

Adding an entry to the Linux Kernel .config file

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