[U-Boot-Users] Configuring U-Boot for MPC8349E in little endian mode

David Hawkins dwh at ovro.caltech.edu
Fri May 2 23:48:27 CEST 2008


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





More information about the U-Boot mailing list