[U-Boot-Users] implementation of lowboot for pq2fads-zu board

Jerry Van Baren gerald.vanbaren at smiths-aerospace.com
Fri Nov 3 16:10:12 CET 2006

Ben Warren wrote:
> Nethra,
> On Fri, 2006-11-03 at 04:03 -0800, Nethra wrote:
>> kindly suggest the changes to be done.
>> 2. if i want do changes in u-boot-1.1.1for custom board what are all the
>> changes to be done.
>> thanks
>> Nethra
> Here are the initial steps.  Once you've completed them, feel free to
> post follow-on questions:
> 1.	The U-boot code that you have is old.  Please get the latest,
> nominally version 1.1.6, which is available at
> git://www.denx.de/git/u-boot.git  
> You'll need to install and learn the 'git' source code control
> application.  I'd explain how, but you'll learn much more if you figure
> it out for yourself.  Google will help you here.  OK, here's one link:
> http://www.kernel.org/pub/software/scm/git/docs/everyday.html#Individual
> %20Developer%20(Participant)
> 2.	Read the excellent documentation at
> http://www.denx.de/wiki/DULG/Manual
> 3.	Read the README that accompanies the U-boot code.  There is a section
> on code porting that will be useful.  There is also lots of
> documentation in the /doc directory, some of which may be helpful to
> you.
> 4.	Read and understand the source code for the 'pq2fads' board that your
> custom board is based on.
> regards,
> Ben

Do all of the above, then when you make your configuration, use the 
$ make PQ2FADS-ZU_lowboot_config

Look at the top level Makefile to see what it is doing, it is putting 
some customizing stuff in the include/config.h file (make the 
configuration and then look in the config.h file).

You need to switch a jumper J7 to short pins 1-2 (default is 2-3) to 
switch from fetching the HRCW from the BCSR register to fetching the 
HRCW from flash.

DON'T erase the high boot version of u-boot - by switching the jumper J7 
back, you can recover from loading a bad u-boot in the lowboot position 
by reloading a good lowboot u-boot.  DAMHIKT.


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