[U-Boot-Users] data bus bit reversal

[DeLaGarza, Robert]

I have a question that isn't strictly related to U-Boot.  I hope it's not 
unacceptable.

The old PPCBoot source included a macro used during Flash programming on a 
Musenki board (I suppose the U-Boot code still contains this, but I haven't 
checked).  The macro uses a look-up table to reverse the bits within a 
byte--MSB to LSB, LSB to MSB, and so forth.

We have a custom MPC8241 board with the same problem: the lines on the 
8-bit data bus between the PPC and the Flash device are reversed.  We're 
using an AMC/Metrowerks PowerTAP PRO for debugging and Flash programming, 
and it appears that there is no way to have the built-in Flash programming 
algorithms compensate for the bit reversal.

My question is this: are there other Flash programmers (such as the one in 
the BDI2000) that can indeed compensate for the bit reversal?

My current plan is to use custom Flash programming code running in SDRAM, 
but it would be nice if there was a tool that let me bypass this process.

Again, I hope this message isn't too far off-topic.  Thanks for any help.

-Robert DeLaGarza