Re: [PATCH 2/2] kconfig: support out of tree KCONFIG_CONFIG

[Nicolas Porcel <nicolasporcel06@gmail.com>]

On Sat, Sep 02, 2017 at 04:31:44PM +0900, Masahiro Yamada wrote:
> 2017-08-19 7:20 GMT+09:00 Nicolas Porcel <nicolasporcel06@gmail.com>:
> 
> If the kernel source is not writable, O= should be used.

You are right, I didn't know O= worked for kernel config.

> I think KCONFIG_CONFIG only contains a file name
> and this restriction is intentional
> because conf_write() might be called with a directory path (for
> example from gconf.c)
> 
> 
> If we change the behavior,
> I think conf_write() should just error-out
> when directory path is given.
> 

When I build a kernel, I set KCONFIG_CONFIG to reference a file on a
different file-system than the build directory. It used to work before
kernel 4.12, hence my patch.

I now realize that I misunderstood the purpose of this variable. It
also means that it is not possible to store the configuration file
outside the build directory when using silentconfig for instance.

Of course, I can use a symlink with KCONFIG_OVERWRITECONFIG, but it
may be an interesting feature to be able to specify an absolute path
for the kernel config file.

Best regards,

-- 
Nicolas Porcel