[U-Boot-Users] Uboot runs but applications do not?
bilahari
bilahari_akkiraju at yahoo.com
Thu Oct 12 01:42:51 CEST 2006
> I am have not been able to run any application.
>
I had the same problem, but my board had 8343 powerpc
processor, so my load address was 40000 and to run
the application, I had to do
=> tftp 0x40000 /home/bil/hello_world.bin
=> go 0x40004
The start code was at at an offset 4 from my load
address. You may have to consider this. I used nm
utility (powepc-linux-nm ) that was in my cross
compiler's bin directory to look into the hello_world.obj
and saw that the symbol hello_world was at 40004
(I think even a common non cross compiler nm utility will
work too and you should be able to see the addresses,
symbols in your obj file). So use nm to explore
the hello_world.obj and know more about symbols and the
locations of hello_world program.
> Using example code Hello_world.c and further
simplifying it to .....
> printf("hello world" line only.
As written in other reply by wolgang Denk, you may have
simplified the code too much. app_start() is necessary
as it zero's out BSS ( necessary for things to work
poperly, I remeber hello_world working properly
even without app_start() but forget about it, I think you may
just leave it there).
>
> results in. It seems to me I have not gotten an interface to Uboot stdio
> correct.
>
To cross check wether you have interface to
u-boot provided printf, do this :
The u-boot exports the interface in a export
list present in
/u-boot-install-dir/include/exports.h.
Also look in
/u-boot-install-dir/include/_exports.h
Most probably you should find a line
EXPORT_FUNC(printf)here too,
if you find these, it means that you have
access to the u-boot printf functionality.
Bilahari
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