[U-Boot] L2 cache and LCD on sunxi

[Simon Glass]

Hi Hans,

On 22 December 2014 at 09:45, Hans de Goede <hdegoede at redhat.com> wrote:
> Hi,
>
> On 21-12-14 19:52, Simon Glass wrote:
>>
>> Hi,
>>
>> I ran up a banana PI and noticed that HDMI works in U-Boot. Great!
>>
>> Scrolling seems very slow though - is the L2 cache disabled perhaps?
>
>
> I don't think so, but it could be, I think the scrolling code is just
> very inefficient. Feel free to poke things a bit around this, ARM
> cache management is not my forte.

I think it need ssomething like the code in exynos/soc.c - see
v7_outer_cache_enable().

Even with the 7 inch it's very slow.

>
>> Also are there instructions for getting an LCD running in U-Boot? I
>> have an Olimex A20-OLinuxion-MICRO (what a mouthful!) with a 7 inch
>> display if that matters. I can't find any useful information so far.
>
>
> He he, your in luck I've been working on LCD support the last few days,
> and I just got the olimex 7" lcd running on olimex boards :)
>
> If you use my current wip tree:
>
> https://github.com/jwrdegoede/u-boot-sunxi/tree/sunxi-wip
>
> And build for the A20-OLinuXino_MICRO-lcd7_defconfig things should
> just work, assuming you are using the standard olimex 7" lcd with
> a standard 40 pins pata cable.
>
> Note in order for the kernel to take over the fb you need a small
> kernel patch on top of 3.19, I've attached the patch.

That's great, yes it works!

Looking at the patches, rather than adding new board configs and
CONFIGs I think it should be device-tree-controlled. Maybe an
environment variable could hold the display type?

Regards,
Simon