Building images without kernel

Building images without kernel

[Claudius Heine]

Hi,

my use-case is creating nfs root file systems with isar, so I don't need 
the kernel created by isar. That worked with older isar version.
Now we have a strong dependency to some kernel.

Using my multiconfig it currently complains about:
     Nothing PROVIDES 'linux-image-${KERNEL_NAME}'

Sure I can just set `KERNEL_IMAGE` to something, but wouldn't that then 
deploy the kernel to my rfs?

Cheers,
Claudius

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Re: Building images without kernel

[Jan Kiszka]

On 2018-04-05 11:30, Claudius Heine wrote:
> Hi,
> 
> my use-case is creating nfs root file systems with isar, so I don't need
> the kernel created by isar. That worked with older isar version.
> Now we have a strong dependency to some kernel.
> 
> Using my multiconfig it currently complains about:
>     Nothing PROVIDES 'linux-image-${KERNEL_NAME}'
> 
> Sure I can just set `KERNEL_IMAGE` to something, but wouldn't that then
> deploy the kernel to my rfs?

That hard dependency is encoded into isar-image-base.bb (I think it was
before as well). You could probably do IMAGE_INSTALL_remove, or you
provide a linux-image-none recipe (KERNEL_NAME=none to install nothing
in your image. Maybe we should include such a dummy recipe upstream so
that this case can be handled without boilerplate code.

Jan

Re: Building images without kernel

[Alexander Smirnov]

On 04/05/2018 12:40 PM, Jan Kiszka wrote:
> On 2018-04-05 11:30, Claudius Heine wrote:
>> Hi,
>>
>> my use-case is creating nfs root file systems with isar, so I don't need
>> the kernel created by isar. That worked with older isar version.
>> Now we have a strong dependency to some kernel.
>>
>> Using my multiconfig it currently complains about:
>>      Nothing PROVIDES 'linux-image-${KERNEL_NAME}'
>>
>> Sure I can just set `KERNEL_IMAGE` to something, but wouldn't that then
>> deploy the kernel to my rfs?
> 
> That hard dependency is encoded into isar-image-base.bb (I think it was
> before as well). You could probably do IMAGE_INSTALL_remove, or you
> provide a linux-image-none recipe (KERNEL_NAME=none to install nothing
> in your image. Maybe we should include such a dummy recipe upstream so
> that this case can be handled without boilerplate code.
> 

Another approach could be distro features, like it's done in Yocto via 
DISTRO_FEATURES. The features could be: kernel, bootloader, debug etc... 
In general I think it's eventually very useful cascading.

Alex