Re: CAN ISO-TP Availability for Yocto

[Oliver Hartkopp <socketcan@hartkopp.net>]

Just an addition:

I've looked into openembedded

https://github.com/openembedded/meta-openembedded/commits/master/meta-oe/recipes-extended/socketcan/can-isotp_git.bb

and iso-tp was blacklisted here:

https://github.com/openembedded/meta-openembedded/commit/649d491b213f19f4d7382cc20d824785d0965310#diff-a0aaa6de49c7f7360101571e2fe547248bb29c611c1bcf1f358667007c12f6b5

The recipe update is from 2019-08-29
https://github.com/openembedded/meta-openembedded/commit/d6b4dee1b16b6b2bf5c502f23be7eb05ad2f675e#diff-a0aaa6de49c7f7360101571e2fe547248bb29c611c1bcf1f358667007c12f6b5

So I wonder why isotp was blacklisted instead of upgrading the commit 
hash to a more recent version of the can-isotp GitHub repo ...

¯\_(ツ)_/¯

Btw. they use the out-of-tree implementation instead of creating a 
patch. Hm.



On 04.12.20 09:14, Oliver Hartkopp wrote:
> Hello Jin,
> 
> On 03.12.20 23:50, Jin Park wrote:
> 
>> I tried to build and load module and build image with Yocto frameworks 
>> and it showed the error like this.
>>
>> ‘can-isotp was skipped: Recipe is blacklisted: Kernel module Needs 
>> forward porting to kernel 5.2+’
>>
>> Do you know whether CAN ISO-TP supports Yocto project?
> 
> the CAN ISO-TP support will be in mainline Linux starting with Linux 
> kernel 5.10.
> 
> For older kernels you may use the implementation for out-of-tree 
> compilation which is located here:
> https://github.com/hartkopp/can-isotp (master branch)
> 
> There is also a more up-to-date version in the 4.17+ branch which I used 
> to prepare the mainline process.
> 
> But out-of-tree compilation is probably not to right way to integrate 
> iso-tp into Yocto. I would suggest to backport the current mainline code 
> to Kernel 5.4 and create a patch for it so that is applied to the kernel 
> code before the kernel compilation process.
> (Is this already the process in Yocto to have a patch like this which 
> lead to the Yocto error message??)
> 
> Backporting the 5.10-rc mainline code to 5.4 is really easy as only one 
> thing needs to be changed/reverted:
> https://github.com/hartkopp/can-isotp/commit/98986fc2f07cb5c7fa73a86d9b4b3ae417d35d79 
> 
> 
>> I tried to bake module in below condition.
>>
>>   * Hardware: VAR-SOM-MX8M-NANO
>>   * Yocto version: Dunfell Kernel 5.4.74
>>
>> jin@jin-ThinkPad-P51:~/var-fslc-yocto$ bitbake can-isotp
>>
>> WARNING: You have included the meta-virtualization layer, but 
>> 'virtualization' has not been enabled in your DISTRO_FEATURES. Some 
>> bbappend files may not take effect. See the meta-virtualization README 
>> for details on enabling virtualization support.
>>
>> Loading cache: 100% 
>> |#########################################################################################################################################################################| 
>> Time: 0:00:00
>>
>> Loaded 3848 entries from dependency cache.
>>
>> ERROR: Nothing PROVIDES 'can-isotp'
>>
>> can-isotp was skipped: Recipe is blacklisted: Kernel module Needs 
>> forward porting to kernel 5.2+
> 
> I'm not familiar with Yocto. But when they created a kernel patch 
> including code/include/Kconfig/Makefile (as suggested above) it should 
> be easy to backport the mainline code as base for a 5.4 kernel patch.
> 
> Please let me know if you have problems creating such a 5.4 kernel patch.
> 
> Regards,
> Oliver
>