[U-Boot] [RFC] ARM: U-boot and 2 GiB of ram with get_ram_size only being long

[Oliver Schinagl <oliver+list@schinagl.nl>]

On 10/18/13 18:43, Scott Wood wrote:
> On Fri, 2013-10-18 at 02:04 +0200, Oliver Schinagl wrote:
>> So now that that's settled, anything fundamentally wrong with my patch? :)
>
> Did you see my other mail in this thread?  This patch is sort of OK for
Sorry I did and I got distracted from it.

> raising the get_ram_size() limit from 1 GiB to 2 GiB (with an increased
> risk of false positives from I/O), but it can't go beyond that on
I'd ask 'how so' but I'm not sure I'd understand anyway ;)

> 32-bit.  A better approach would be to get the RAM size from the memory
> controller, which is what we do on many Freescale PPC boards.
Not possible for us at this moment. The memory controller is programed 
with hard-coded values on a per board basis. I think we could 
technically obtain values via/from the memory controller, but have no 
knowledge at this moment. Allwinner has a tool, livesuit, which is used 
to flash full disk images to a device. We currently guesstimate that 
livesuit can somehow detect the memory parameters and injects it into 
the stock bootloader. But we really have no clue if that really happens 
or how it's done. So we rely on extracting the information from a 
running stock android/linux and hardcode it into u-boot.

Oliver

>
> -Scott
>
>
>