[meta-ti] Trouble modifying defconfig for linux-ti-staging_rt recipe

[Glenn Schmottlach]

On Mon, Mar 20, 2017 at 11:54 AM, Denys Dmytriyenko <denys at ti.com> wrote:
> On Mon, Mar 20, 2017 at 11:44:16AM -0400, Glenn Schmottlach wrote:
>> I am having trouble modifying the kernel configuration for the
>> following TI kernel recipe using the Yocto Morty environment:
>>
>> linux-ti-staging-rt_4.9.bb
>>
>> I have created my own layer and with a *.bbappend file for this recipe, e.g.
>>
>> linux-ti-staging-rt_4.9.bbappend
>>
>> It appears the TI kernel recipes are not (yet) proper "Yocto" kernel
>> recipes in that they are not "fragment" aware.
>
> TI kernel recipe is not "Yocto" kernel (which is really to say WindRiver
> format), but the fragment support got upstreamed to the mainline kernel and
> kernel itself now supports config fragments! That is what TI kernel uses and
> meta-ti kernel recipe supports.
>

Thanks for that clarification. I wasn't aware of the two "flavors" of
fragment support. It certainly would be nice if a consistent approach
(between Yocto and the Kernel) could be adopted. I suspect this will
be sorted out in time.

>> It appears I cannot do
>> the following inside of my *.bbappend recipe:
>>
>> FILESEXTRAPATHS_prepend := "${THISDIR}/${PN}:"
>> SRC_URI += "file://eem.cfg"
>
> You can add any additional fragments you want to be applied by the recipe to
> KERNEL_CONFIG_FRAGMENTS variable.
>
>

This what I ultimately did . . . appended a fully qualified path to my
fragment to the KERNEL_CONFIG_FRAGMENTS variable. As a suggestion,
this might be something useful to include in the README for the
meta-ti layer. I suspect others might have a similar need to modify
the kernel configuration and once described, it (now) seems
straightforward.

>> Inside of "eem.cfg" I want to set the following kernel options:
>>
>> CONFIG_USB_NET_CDC_EEM=m
>> CONFIG_USB_F_EEM=m
>> CONFIG_USB_ETH_EEM=y
>>
>> This has no affect. I tried creating my own defconfig based on the
>> '.config' generated from the original recipe. I modified my *.bbappend
>> file as follows:
>>
>> FILESEXTRAPATHS_prepend := "${THISDIR}/${PN}:"
>> SRC_URI += "file://defconfig"
>>
>> Again, my defconfig is not applied to the build.
>
> It already has file://defconfig in SRC_URI, that's how it works and gets the
> fragments assembled.
>
> What's your platform? Are you sure one of the existing defconfigs are not
> used instead?

I'm building for a BeagleBoneBlack so I expect it's using the
defconfig for that platform.

>
>> I even tried patching kernel-source/ti_config_fragments and placing a
>> eem.cfg in that directory hoping the configuration generation script
>> (defconfig_builder.sh) might apply this fragment.
>>
>> FILESEXTRAPATHS_prepend := "${THISDIR}/${PN}:"
>> SRC_URI += "file://0001-eem-config.patch"
>>
>> Where the patch contains:
>>
>> Index: kernel-source/ti_config_fragments/eem.cfg
>> ===================================================================
>> --- /dev/null
>> +++ kernel-source/ti_config_fragments/eem.cfg
>> @@ -0,0 +1,4 @@
>> +CONFIG_USB_NET_CDC_EEM=m
>> +CONFIG_USB_F_EEM=m
>> +CONFIG_USB_ETH_EEM=y
>> +
>>
>> Unfortunately this did not work either.
>
> You also need to update the "map" file, which basically lists all the
> fragments it needs to assemble for a platform. And platform's defconfig only
> points to one of the entries in the map file.
>

Sorry if I'm a bit dense, but could you elaborate on this "map" file.
Where do I find it? What do I need to change? Do I need modify this
file in addition to modifying the KERNEL_CONFIG_FRAGMENTS as you
mentioned above?

Thanks for your patience (and help),

Glenn