[LEDE-DEV] [PATCH 2/2] ipq806x: Add support for ipq40xx subtarget

[Felix Fietkau]

On 2017-04-17 13:26, Ram Chandra Jangir wrote:
> Hi Felix,
> 
>> What's the reason for making it a separate subtarget?
> 
> We would like to add ipq40xx as subtarget for following reasons.
> 1. ipq40xx is different SoC than existing ipq806x
> 2. Would like to have SoC specific images, so that kernel configs can be tweaked per SoC
> 3. SoC specific images will be smaller in size & faster boot-time
While some drivers are indeed SoC specific, I think ipq40xx and ipq806x
do have a lot of overlap. I don't think that images will be much smaller
with SoC specific subtargets, at least not enough to make any
*practical* difference.

> 4. Newer SoC may have exclusive FWs which needs compile time differentiation.
Firmware should be packaged anyway, and can thus be handled via device
profiles.

> 5. There is new SoC(ipq807x) under development, which is based on
> ARMv8. Hence we will need subtarget approach to accommodate new SoC.
I agree that there should be a separate subtarget for ipq807x, but I
don't think it makes sense for ipq40xx.

Please keep in mind that each extra build target has a visible cost in
buildbot and download server resources, so I would really like to avoid
adding more except where there are strong reasons to do so.

- Felix