[yocto] Configuring a layer to support multiple targets

[Chris Tapp]

On 17 Aug 2011, at 16:18, Bruce Ashfield wrote:

> In this sense, the defconfig is simply a name to trigger
> specific processing. Just capture and call your .config
> 'defconfig' and you'll get a translation of those settings
> into the build.


That's what I've done. I used 'make xconfig' to modify the .config  
file (resulting from bitbake -c compile virtual/kernel). However,  
turning off CONFIG_USB_SERIAL and saving the result as a defconfig  
isn't quite what's needed.

Consider the .config fragment:

CONFIG_USB_SERIAL=y
CONFIG_USB_SERIAL_FTDI_SIO=y

The corresponding defconfig fragment produced when usb serial is  
disabled in xconfig results is simply:

# CONFIG_USB_SERIAL is not set

When the defconfig is merged with the .config I get:

# CONFIG_USB_SERIAL is not set
CONFIG_USB_SERIAL_FTDI_SIO=y

This means the FTDI module is still present in the kernel.

I can get rid of these by manually adding 'not set' entries in the  
defconfig, but it would be easier if I could replace the .config  
rather than patch it.

Chris Tapp

opensource at keylevel.com
www.keylevel.com