[U-Boot] [PATCH 2/3] video: add support for display controller in MB86R0x SoCs

[Wolfgang Denk]

Dear Matthias,

in message <4BD7D5DD.6080701 at arcor.de> you wrote:
>
> >> +	pGD->memSize = VIDEO_MEM_SIZE;
> >> +	pGD->frameAdrs = PHYS_SDRAM + PHYS_SDRAM_SIZE - VIDEO_MEM_SIZE;
> >
> > Please pay attention to the global memory map requirements. PRAM might
> > go first.
> 
> Can you please explain this a bit more in detail? I checked the source 
> and README for CONFIG_PRAM and it seems to be reserving some space at 
> the end of RAM. But I have only found reference to it in ppc and m68k code.

Right. But there is a chance that the ARM implementation might be
reworked soon, and then it will follow the documented approach as
well, so better start correctly from the beginning so you don;t run
into conflicts soon.

> What would be the correct way to reserve some 2MB-4MB at the end of 
> system RAM as a framebuffer for the integrated graphics device?

See the PPC implementation for reference.

Best regards,

Wolfgang Denk

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