Re: [PATCH v2] Install kernel via replaceable recipe

[Alexander Smirnov <asmirnov@ilbers.de>]

On 01/30/2018 01:52 PM, Jan Kiszka wrote:
> On 2018-01-30 11:49, Alexander Smirnov wrote:
>> On 01/30/2018 12:34 PM, Jan Kiszka wrote:
>>> From: Jan Kiszka <jan.kiszka@siemens.com>
>>>
>>> This simplifies the common task of using a custom kernel instead of the
>>> pre-selected debian variant: Move the kernel installation into a dummy
>>> dpkg-raw recipe that only has the kernel package as dependency.
>>>
>>> Which recipe is used for providing the kernel can now be selected via
>>> the well-know PREFERRED_PROVIDER_virtual/kernel, just like in OE.
>>>
>>> The kernel package name is communicated from the target multiconfig file
>>> to the linux-debian recipe via the DEBIAN_KERNEL variable.
>>
>> Why it's Debian kernel? This could be a bit confusing, Isar doesn'y
>> support only official Debian kernel. For example Isar already supports
>> Raspbian which contains its own Raspbian kernel.
> 
> I'm always open for better name proposals.

So, if no reasons, I'd propose:
  - KERNEL_PACKAGE
  - KERNEL_PACKAGE_NAME


[...]


>>> +inherit dpkg-raw
>>
>> Do I understand correctly, that this recipe creates fake package that
>> has dependency from the upstream kernel? So in target rootfs 2 kernel
>> packages will be installed?
> 
> Right, one empty linux-debian meta package and the real one. The former
> allows us to trivially kick out the latter in favor of a custom kernel.
> 

What is the benefit of this complexity? If we need to have over-writable 
kernel name, it would be enough to pass current DEBIAN_KERNEL variable 
directly to IMAGE_INSTALL. The same result, but no extra recipe in Isar 
tree and no pseudo package in target rootfs.

Alex