Re: [PATCH] ARM: dts: aspeed: Update reserved memory nodes for zaius and witherspoon

[Cyril Bur <cyrilbur@gmail.com>]

On Thu, 2017-02-16 at 08:05 -0600, Patrick Williams wrote:
> On Thu, Feb 16, 2017 at 04:49:22PM +1100, Cyril Bur wrote:
> > -		flash_memory: region@94000000 {
> > +		flash_memory: region@98000000 {
> >  			no-map;
> > -			reg = <0x94000000 0x04000000>; /* 64M */
> > +			reg = <0x98000000 0x04000000>; /* 64M */
> > +		};
> > +
> > +		vga_memory: framebuffer@9c000000 {
> > +			no-map;
> > +			reg = <0x9c000000 0x04000000>; /* 64MB */
> 
> Do we really have to allocate 64MB to a VGA framebuffer?  We can store a
> 4K resolution monitor with 32bit color in 32MB, so why is it required to
> reserve this much memory?  Between this and the PNOR memory region, now
> 1/4th of the BMCs memory is reserved.

The reservation of 64MB is because the hardware is capable of using
64MB, therefore the host can use that region of memory. We're playing
it safe here by ensuring the BMC doesn't use any of it to avoid any
possibility of the host corrupting BMC memory. This is the most generic
dts for the platform so we've gone with stability over performance.


Cyril

>