[U-Boot-Users] [PATCH] 405 OCM warning
wd at denx.de
Fri Jul 2 00:00:09 CEST 2004
In message <20040612190145.GF12815 at pengutronix.de> you wrote:
> any chance to get this in? It took too much time to let anybody else do
the same stuff again...
Ummm... actually I think this is a FAQ which has been answered somewhere
> NOTE: for IBM 405GP the On Chip Memory (OCM) is mapped on virtual
> addresses! So take care that you configure it to be mapped
> (CFG_OCM_DATA_ADDR) in an area which is not used by your operating
> system's virtual addresses. For Linux it has to be located above the
> maximum task size (see CONFIG_TASK_SIZE in the Linux configuration).
> Otherwhise you will see strange effects with your user land stack.
Isn't it the other way round? U-Boot does not use "virtual addresses"
as it doesn't enable the MMU for virtual memory. It's the Linux
kernel which uses a 1:1 physical to virtual mapping for certain
Or am I missing something?
Software Engineering: Embedded and Realtime Systems, Embedded Linux
Phone: (+49)-8142-4596-87 Fax: (+49)-8142-4596-88 Email: wd at denx.de
It is easier to change the specification to fit the program than vice
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