# make oldconfig menuconfig

## Cr0t

I have been having this strange issue and this has not happened for the first time.... and not only on one machine.

If I upgrade a kernel I copy over the old .config file into the new source and run a 'make oldconfig menuconfig'. It works, but the problem is, that sometimes new kernel features are missing and I can only get them if I start over from scratch.

'make mrproper menuconfig' that will show me all the options. The issue with that is, that I need to re-configure the entire kernel, which is a pain.

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## DONAHUE

If you skip "copy over the old .config file into the new source and run a" and just

```
cd /usr/src/linux

make oldconfig
```

where /usr/src/linux does not yet contain a .config file you will find yourself running in a world where differences between the oldconfig and the defconfig for the new kernel provide prompts like: *Quote:*   

> In file included from scripts/kconfig/zconf.tab.c:2451:
> 
> scripts/kconfig/confdata.c: In function 'conf_write':
> 
> scripts/kconfig/confdata.c:508: warning: ignoring return value of 'fwrite', declared with attribute warn_unused_result
> ...

 

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## keenblade

Take a look at Kernel method: make menuconfig vs make oldconfig.

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## Cr0t

 *keenblade wrote:*   

> Take a look at Kernel method: make menuconfig vs make oldconfig.

 Ah.... sh*t.!

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## Hu

 *Cr0t wrote:*   

> If I upgrade a kernel I copy over the old .config file into the new source and run a 'make oldconfig menuconfig'. It works, but the problem is, that sometimes new kernel features are missing and I can only get them if I start over from scratch.

 Some options are added with a dependency on a value you may have set differently from the kernel's defconfig for your architecture.  In general, this should not be a problem, as options tend to be added with dependencies that expose them to people who are ready to try them.  If you cannot see them, it may be because you configured your kernel to prefer only well vetted drivers that the developers are confident will work well for everyone.  If you just want to browse, you could reset to default options instead of using make oldconfig.  If you only need to find a few new features, search for them and then adjust your choices to satisfy their dependencies.  Generally, make oldconfig should work well for you, as long as you do not get in the habit of skipping over multiple major releases in a single bound.

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