[U-Boot-Users] PATCH] Add 8641reset commmand for mpc8641hpcn board

Jon Loeliger jdl at freescale.com
Thu Mar 29 18:35:36 CEST 2007

On Sun, 2007-03-25 at 15:23, Wolfgang Denk wrote:

> Conceptually  I  disagree.  This  command  implements  two  different
> functions:  (1)  it  adjusts  some system parameters (but this change
> will only take affect after a reboot), and (2) it performs a  reboot.
> Following  good  old  Unix design, you should split this command into
> it's logical parts. Then you will probably realize  that  the  second
> part  (perform  a  reset) already exists and can be reused instead of
> reimplemented.


I went a little Search-And-Annoy mission here recently, and
tracked down the board designer for the 8641 HPCN (and the
MPC8544DS), and talked about the FPGA (called "PIXIS")

It turns out that the normal SW controlled board reset
operation is distinctly different than the reset operation
initiated through the FPGA (the "GO" bit).  Specifically,
the FPGA 'GO' bit drives a reset sequencer that allows for
the additional state that has been programmed through PIXIS
for the alternate speeds, flash bank selections, etc.
That state is not used through the normal reset mechanism.

Effectively, there really are two reset operations, one which
is explicitly tied to the FPGA reset operation as currently
implemented in the patch as submitted.

Naturally, I am happy to clean up the other issues you
pointed out in your review of the patch and resubmit it.


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