[U-Boot-Users] clarifications u-boot for arm

Jerry Van Baren gerald.vanbaren at smiths-aerospace.com
Fri Jul 14 16:23:36 CEST 2006


See bottom posted reply.

Russell Peterson wrote:
> Hello,
>  
> The answer to your question "who calls start_armboot?"  is answered by 
> you ASM code below.  Hint... take a close look at the regsiter you are 
> loading.
>  
> :-)
>  
> Regards,
>  
> Russell
> 
>  
> On 7/14/06, *Ram* <vshrirama at gmail.com <mailto:vshrirama at gmail.com>> wrote:
> 
>     Hi,
>       Thanks for your response. I have gone much further and would like
>     to know If
> 
>          ldr pc, _start_armboot
>         _start_armboot:
>             .word start_armboot
> 
> 
>        Does this really invoke start_armboot?.  This is because
>     _start_armboot is what is
>        stored in pc and not start_armboot and there is also a branch
>     point _start_armboot (underscore start_armboot) Please see above.
> 
>       Actually the above declares a variable start_armboot and does not
>     invoke the function
>       start_armboot. If this is true, then who calls start_armboot?

[snip - I believe your observations are correct, but am not an expert]

>     Thanks and Regards,
>     sriram

Sriram:

C compiler naming convention prepends an underscore to the C function 
name so the C function start_armboot() can be referenced from assembly 
as a branch (call) to the label _start_armboot.

gvb





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