[U-Boot] Early malloc() summary

[Marek Vasut]

Dear Albert ARIBAUD,

> Hi Marek,
> 
> On Tue, 14 Aug 2012 14:37:29 +0200, Marek Vasut <marex at denx.de> wrote:
> > Dear Tomas Hlavacek,
> > 
> > > Hello Marek,
> > > 
> > > On Sun, Aug 12, 2012 at 1:16 AM, Marek Vasut <marex at denx.de> wrote:
> > > > So ... we should aim for firing up the real mallocator as soon as
> > > > possible and maybe implement discontigmem (sparsemem) into it, so
> > > > we don't have to bother with relocating pointers maybe?
> > > > 
> > > > The only problem I see is platforms where the memory disappears.
> > > 
> > > I doubt that on ARM for instance you can set off real mallocator
> > > that early without completely rewriting it.
> > 
> > Esp. on ARM, I won't see much of a problem. You usually have some
> > small SRAM where such allocator could run.
> 
> ... or not; for instance, orion5x / edminiv2 does not have such SRAM. So
> how do we handle this there?

Lock cachelines on top of RAM and make some ... indeed, I mentioned it somewhere 
in this thread before that there are such devices.

But in case we lock cachelines, then start DRAM underneath, can we somehow 
(painlessly) trigger writeback of the data back into DRAM so we can unlock the 
cache?

> Amicalement,

Best regards,
Marek Vasut