[U-Boot-Users] Uboot runs but applications do not?

[bilahari]

> 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