[U-Boot] Standalone application after powerup

[U-Boot] Standalone application after powerup

[Nagesh.ML]

Hi,

I am trying to run the hello_world standalone application on my powerpc
board(ppc 82xx). I get it worked right, when the u-boot prompt comes up by
copying the hello_world.bin from flash to the RAM space(0x40000) and then
using the "go 0x40004" command. Everyting works fine in this case.

The next case I tried was using the run_command() function and passing the
"cp" and "go"  command with appropriate flash and RAM addresses with that as
the arguments, After powerup and executing some of the cpu and memory
controller initializations..I call the run_command() functions. My board
resets giving program check exception.

What could be the possible solution to include the standalone application in
my board powerup sequence?

--Nagesh
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[U-Boot] Standalone application after powerup

[Wolfgang Denk]

Dear "Nagesh.ML",

In message <19914708.post@talk.nabble.com> you wrote:
> 
> What could be the possible solution to include the standalone application in
> my board powerup sequence?

This depends on where you want to include it. I think it  is  obvious
that   SA   applications  require  a  substantial  amount  of  U-Boot
infrastructure to be running. By design,  they  are  intended  to  be
called  only  when any other interactive command can be exectuted. If
you know exactly what you are  doing,  you  may  run  them  a  little
earlier, but probbaly not much.

Me recommendation is: if you want to run SA applications  early,  you
can do this from the "preboot" hook. Any earlier point may or may not
work,  and  especially there is no guarantee that this will not break
in any future versions of U-Boot.

Keep in mind what SA applications are used for - especailly, they are
NOT intended to sneak in propriatary  initialization  code  in  early
boot  stages,  and this is about the only reason I can imagine to use
them in that early.

Best regards,

Wolfgang Denk

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