Problem booting Linux 2.6 on Virtex-4

David Baird dhbaird at
Tue Jan 15 07:11:48 EST 2008

On Jan 14, 2008 1:37 AM, Enno Lübbers <enno.luebbers at> wrote:
> Hello David,
> Am 14.01.2008 um 06:12 schrieb David Baird:
> > I'm having trouble with getting Linux to boot farther than early_init.
> > [...]
> > So, I experimented further and discovered that different memory
> > regions seem to be aliased on to each other every 2*32*256 bytes.
> This sounds either like a wrong programming of an BRx/ORx memory
> controller register pair (which, AFAIK, the PPC405 does not have), or
> like a messed up address map in EDK. My guess is that an optimized/
> sloppy implementation of the address decoder for some peripheral in an
> EDK system could produce something like you described; or there's a
> block RAM that's attached to a controller in the wrong way; or the
> bank/address parameters of the DDR controller don't match the physical
> setup... there's a lot that can go wrong obviously on a configurable
> SoC.

What has been confusing me is that I am unable to reproduce the
problem in real mode.  I can only reproduce the problem in virtual
mode.  This leads me to believe, perhaps mistakenly, that the hardware
is implemented okay.  OTOH, neither can I see anything wrong with the

> Can you be more specific about your hardware platform? Is this a
> reference design? What board are you using?

I am currently testing code on the ML403 evaluation board.  I used the
Base System Builder in EDK to create the hardware design and DDR SDRAM
is being used as the main RAM starting at address 0x00000000 and also
with OCM BRAM mapped at the very end of the address space (so that
0xfffffffc can contain code to execute on startup).

I am now trying to experiment with the hardware and see if I can find
a hardware reference design.  I will let you know what I figure out.


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