From: Domen Puncer <domen.puncer@telargo•com>
To: Ming Liu <eemingliu@hotmail•com>
Cc: linuxppc-embedded@ozlabs•org
Subject: Re: a question on "iowrite32()"
Date: Thu, 7 Jun 2007 08:20:54 +0200 [thread overview]
Message-ID: <20070607062054.GD23294@moe.telargo.com> (raw)
In-Reply-To: <BAY138-F6B2DA6BEF021C7026E522B2270@phx.gbl>
On 06/06/07 19:30 +0000, Ming Liu wrote:
> Dear all,
> I am writing a device driver for my customized PLB hardware module on my
> PPC405 & Xilinx ML403 architecture. In the driver code, I use a
> "iowrite32()" function to initiate a DMA transfer. However, I found that if
> I program as "iowrite32(0x12345678, address);", actually I am writing
> 0x87654321 to that address. However if I write a standalone program without
> a Linux OS, the Xilinx function "XIo_Out32()" just write the correct value
> 0x12345678 into address. Can anyone explain my why this happens? I know
> that PPC405 is a big-endian system. But I don't think this is a endian
> problem. After all endian is only an issue of the CPU architecture, not the
> OS. Am I right?
out_be32?
I recall something about iowrite32 being PCI stuff and therefore little
endian, but don't count on this being right.
Domen
next prev parent reply other threads:[~2007-06-07 6:21 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2007-06-06 19:30 a question on "iowrite32()" Ming Liu
2007-06-07 6:20 ` Domen Puncer [this message]
2007-06-07 10:01 ` Arnd Bergmann
2007-06-07 11:20 ` Ming Liu
2007-06-07 14:09 ` Arnd Bergmann
2007-06-08 13:51 ` Ming Liu
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