Re: start.S and ld-script

[<ste...@el...>]

On Wed, Nov 19, 2003 at 05:18:46PM +0530, Yamijala Sridhar wrote:
> Hi All !
>  

Hi.

[snip]
>  
> After a H/W Reset, the instruction at address 0x00000000 is executed.
> In the SA-1110 manual, it has been mentioned that this address corresponds
> to the static memory selected by
> nCS0.Let me say, it is a Flash memory. 
>  
> In blob, I found a comment that "The SA-1110 jumps to address 0x00000000
> after a reset. 
> We put a single branch code at this position, which jumps to a safe region
> to do the actual setup".
>  
> Also, in the SA-1110 manual, it has been given that 0x00000000 is the reset
> vector address.
> This means this is the first location where our processor should step into.
>  
> So, is my assumption true that the flash is mapped to Static memory bank 0
> of SA-1110 from addresses 0x00000000 and that
> _start: b reset
>  
> is the first instruction to be executed after a reset?

I am not exactly a Hardware guy, but as I understand things you're correct.

> Moreover, how are the other branches namely: undefined_instruction,
> software_interrupt etc. mapped in S/W to the actual vectors?
> when/how is the first branch to these labels taken?

These are jumped to when the processor encounters the corresponding exception,
for example "undefined instruction" etc.

As I understand it, these vectors are only used in BLOB, for example
Linux defines them differently.

>  
> Thank You
> Sridhar

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