[yocto] defconfig file (or fragment files) not used

[Khem Raj]

On 3/28/18 11:00 PM, Vincent Daanen wrote:
>> On 3/28/18 9:27 AM, Vincent Daanen wrote:
>>> Hi,
>>>
>>> I want to add CAN driver support to the kernel. Here is the procedure
>>> I
>>> followed:
>>>
>>>   1. Generate a .config file
>>>   2. Copy it to meta-myWork/recipes-kernel/linux/files/defconfig
>>>   3. Update it: set at the end the config to enable CAN as follows
>>>
>>> # CAN Bus
>>>
>>> CONFIG_NET=y
>>>
>>> CONFIG_CAN=y
>>>
>>> CONFIG_CAN_RAW=y
>>>
>>> CONFIG_CAN_BCM=y
>>>
>>> CONFIG_CAN_GW=y
>>>
>>> #
>>>
>>> # CAN Device Drivers
>>>
>>> #
>>>
>>> CONFIG_CAN_VCAN=y
>>>
>>> # CONFIG_CAN_SLCAN is not set
>>>
>>> CONFIG_CAN_DEV=y
>>>
>>> # CONFIG_CAN_CALC_BITTIMING is not set
>>>
>>> # CONFIG_CAN_LEDS is not set
>>>
>>> # CONFIG_CAN_SJA1000 is not set
>>>
>>>   4. Update the linux-yocto_%.bbappend file as follows
>>>
>>> SUMMARY = "Recipe to configure kernel as required"
>>>
>>> LICENSE = "CLOSED"
>>>
>>> inherit kernel-yocto
>>>
>>> FILESEXTRAPATHS_prepend := "${THISDIR}/files:"
>>>
>>> SRC_URI += file://defconfig
>>>
>>>   5. Request rebuilt:
>>>
>>> bitbake linux-yocto-rt -c cleansstate
>>>
>>> bitbake -k linux-yocto-rt
>>>
>>> Once the image started (with qemu), I check if the CAN is enabled
>>> (using zcat /proc/config.gz | grep CAN) and I always get “CAN not set”
>>>
>>> I also tried using fragment and I got the same result ☹
>>>
>>> According the user manual, it seems to me I’m doing the right think!
>>>
>>> Does someone know why my defconfig file is not taken into account ?
>>>
>>
>> If you are using linux-yocto for your kernel provider then I wouldr recommend that you look into developer manual.
>>
>> you should look into using config fragments to modify the needed
>> options e.g. see
>> https://www.yoctoproject.org/docs/latest/kernel-dev/kernel-dev.html#cha
>> nging-the-configuration
> 
> I don't understand what you mean. That's what I'm doing. I followed the procedure described in the link you provide... Can u explain ?
> 

Create a file for config fragment say can.cfg and put all options you 
want to change in that file and then add that to SRC_URI
you dont need to create full defconfig.

> Thanks
> 
> Vincent
>