Re: [PATCH 0/8] Convert Netgear WNR854T to devicetree

On Fri, 26 Aug 2016 18:50:33 +0200, Jamie Lentin [off-list ref] wrote:

On Fri, 26 Aug 2016, Andrew Lunn wrote:

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- the factory layout gives you almost no space to play with

Given that the kernel has grown in size over the years, does the
mainline kernel fit in the factory layout?

The factory layout has a 6MB JFFS2 for root & uImage (uboot mounts it by  
default) + 1MB miscellany. So the main restriction on kernel size is the  
size of your userland.

The non-DT mainline layout is 1MB JFFS2 for uImage + 7MB rootfs. Which  
is a closer approximation to other devices with a uImage in it's own  
partition.

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Of course, one could also argue I'm breaking backwards compatibility
at this point by changing it, so maybe I should put it back.

I don't mind breaking backwards compatibility, if the factory defaults
no longer actually work.....

Also, lets think about the users here. This is a very old box. Anybody
playing with one are probably of the sort who tinker with a classic
car in the garage, taking the engine apart and putting it back
together again. I doubt there are users of this box who take their car
in for a service once they are out of windscreen washing water.

My line of thinking was that the only people that will see this default  
partition scheme are people that have just compiled a mainline kernel  
and booted it to see what happens. At which point you probably still  
have the Netgear image in Flash. If you had OpenWRT in Flash then in all  
likelihood you'd already be using an OpenWRT kernel too, with it's own  
flash layout. Finally, you could have rolled your own userland and put  
that on Flash, but by then you should know enough to do what you like :)

Well, that means you have serial console - otherwise without userland it's  
pretty unusable ;) Anyways, I would stay with a modified version of the  
non-DT partitions, with the kernel size increased to ~1.4MB (didn't check  
how much overhead is DT support).


Imre
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