[U-Boot] [PATCH 3/4] fix memory corruption on versatile

[Pavel Herrmann <morpheus.ibis@gmail.com>]

Hi,

On Monday 24 December 2012 14:56:03 Albert ARIBAUD wrote:
> Hi Pavel,
> 
> On Mon, 24 Dec 2012 02:27:53 +0100, Marek Vasut <marex@denx.de> wrote:
> > Dear Pavel Herrmann,
> > 
> > > ARM board.c doesnt respect CONFIG_SYS_GBL_DATA_OFFSET, nor do all boards
> > > set it, so reorganize the memory a bit to avoid overlaps.
> > > 
> > > Signed-off-by: Pavel Herrmann <morpheus.ibis@gmail.com>
> > 
> > Ccing Albert
> > 
> > > ---
> > > 
> > >  include/configs/versatile.h | 2 +-
> > >  1 file changed, 1 insertion(+), 1 deletion(-)
> > > 
> > > diff --git a/include/configs/versatile.h b/include/configs/versatile.h
> > > index c9aed72..27ffffe 100644
> > > --- a/include/configs/versatile.h
> > > +++ b/include/configs/versatile.h
> > > @@ -35,7 +35,7 @@
> > > 
> > >  #define CONFIG_DM_BLOCK
> > >  #define CONFIG_SYS_EARLY_MALLOC
> > >  #define CONFIG_SYS_EARLY_HEAP_ADDR	(CONFIG_SYS_INIT_RAM_ADDR + \
> > > 
> > > -						CONFIG_SYS_GBL_DATA_OFFSET - \
> > > +						CONFIG_SYS_INIT_RAM_SIZE - \
> > > 
> > >  						CONFIG_SYS_EARLY_HEAP_SIZE - 64)
> > >  
> > >  #define CONFIG_SYS_EARLY_HEAP_SIZE	1024
> > 
> > Best regards,
> > Marek Vasut
> 
> I can't seem to find this patch in my inbox or in the list archives.
> 
> Pavel, can you please repost it?
> 
> Amicalement,

I dont really understand why Marek CCed you, this patch is meant to go in the 
DM tree, and i dont see why it should be considered for upstream.

The problem this is trying to solve is that some boards (like the versatile i 
use, as it has upstream qemu support) do define a suspicious looking 
CONFIG_SYS_GBL_DATA_OFFSET, but that macro is not used in the board_init_f. 
instead the GD is placed under the bottom of stack.

This is perfectly fine when we only have GD and stack in memory, but I would 
like to have the early heap in there somewhere, ideally between GD and stack. 
When I set the macros (not knowing that it is actually ignored) to represent 
this layout, the boot failed because the stack was overlapping the GD, so this 
patch changed the layout to [stack][GD][heap][end].

the "optimal" solution would be to have universal (as in that all archs 
board_init_f()s would respect them, and all board configs would have them) 
macros for address of GD, early heap and stack independently (with the obvious 
exception that for stack you have the highest address, while for other you 
have the lowest), so that we can have the originally intended layout ([stack]
[heap][GD][end]), or any other layout for that matter.

This, of course, may not be possible due to various limitations of various 
archs, so I did not attempt to make any such patch, instead just quick-fix the 
board i am using to test early DM initialization.

Hope this clears the confusion

Pavel Herrmann