[meta-xilinx] linux-xlnx kernel recipe changes

[Philip Balister]

On 03/09/2015 02:25 AM, Nathan Rossi wrote:
> Hi all,
> 
> There are some changes that I would like to get feedback on regarding the kernel recipes in meta-xilinx.
> 
> First off, the smaller changes.
> 
> 1. MicroBlaze defaulting to linux-yocto kernel. The mainline and linux-yocto kernels are quite stable regarding MicroBlaze and little has changed (and linux-xlnx kernel provides little in addition to mainline for MicroBlaze).
> 2. Drop linux-xlnx 3.10, this kernel is really old and maintaining it has become a bit problematic.
> 
> So the bigger change is quite different to how the current linux-xlnx recipes work. The idea is to only provide a single linux-xlnx kernel via an autorev kernel recipe based on the 'master' branch (sort of like linux-xlnx-dev). There are a number of reasons why this approach can work better, and there are a number of reasons why it might be less useful than the existing approach. The primary reason why I would like to move to this approach is to better support and maintain a functional linux-xlnx kernel as the Xilinx kernel is maintained on the 'master' branch, including features and bug fixes. Given there can be a number of different versions of the linux-xlnx kernel that users would like to target for their projects, it is still possible for a user to include the linux-xlnx.inc and pin the specific version they are after. However I would really like to get some input from those who are relying/using the linux-xlnx recipes.
> 

AUTOREV is evil. It means you need to be very, very careful how you rev
the repo it points at, and it means users may changes that break
something and this will confuse them.

We use the 3.14 recipe with a bbappend to support a product.

That said, I'd love to see a working recipe based on the a released
Linux kernel.



> There is also the goal to switch Zynq (and ZynqMP in the future) to use linux-yocto by default. However there are still a few drivers that are not upstream that make the linux-yocto kernel a bit limited for the common use cases. I would like to get some feedback on this also to see what everyone is relying on from linux-xlnx to see if some priorities can be made to have this sooner. The list I have at the moment is the following:
> 
>  * macb performance and features (e.g. rgmii2gmii)
>  * QSPI
>  * devcfg

Without devcfg, how is the fpga loaded? We depend on loading the fpga
from the user space application.

Pihlip


> 
> Thanks,
> Nathan
>