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From: David Hawkins <dwh@ovro.caltech.edu>
To: u-boot@lists.denx.de
Subject: [U-Boot-Users] Configuring U-Boot for MPC8349E in little endian mode
Date: Fri, 02 May 2008 14:48:27 -0700	[thread overview]
Message-ID: <481B8C2B.90605@ovro.caltech.edu> (raw)
In-Reply-To: <481B79DE.8030905@freescale.com>

Hi Timur,

>> In either case, you would use the byte-conversion routines to
>> serialize the descriptor entries in memory, or in the source buffer,
>> into the correct endianness before performing enabling the DMA.
> 
> Very true.  However, this means that if the original data is in
> the wrong endian, you have to have a middle layer that modifies
> the data when copying from the source buffer to the DMA buffer. 
> This adds overhead.

This would be the key question for Vivek then.

Does his highest volume data set have any endianness issues
that need to be resolved?

>> If Vivek's application correctly serializes any endian-specific
>> data before using the MPC8349EA DMA controller, then he should
>> have no issues.
> 
> Yes, but it may take him weeks to find all the places in the where the
> endianness matters.

Indeed.

Conversely, it may take months to get a little-endian PowerPC
port working!

:)

Cheers,
Dave

      reply	other threads:[~2008-05-02 21:48 UTC|newest]

Thread overview: 14+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2008-04-30 15:34 [U-Boot-Users] Configuring U-Boot for MPC8349E in little endian mode vivek.trivedi at wipro.com
2008-04-30 15:45 ` Wolfgang Denk
2008-04-30 22:13 ` David Hawkins
2008-05-02  6:14 ` vivek.trivedi at wipro.com
2008-05-02  7:22   ` Kumar Gala
2008-05-02 12:38   ` Jerry Van Baren
2008-05-02 16:35   ` David Hawkins
2008-05-02  9:19 ` vivek.trivedi at wipro.com
2008-05-02 14:34   ` Timur Tabi
2008-05-02 16:52     ` David Hawkins
2008-05-02 19:47       ` Timur Tabi
2008-05-02 20:23         ` David Hawkins
2008-05-02 20:30           ` Timur Tabi
2008-05-02 21:48             ` David Hawkins [this message]

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