[U-Boot] Mips: start.S Questions

[Chetan Nanda <chetannanda@gmail.com>]

On Fri, Aug 21, 2009 at 6:23 PM, Peter Belm <peterbelm@gmail.com> wrote:

> >
> > This is not quite correct.  "romReserved" is only used for the, well,
> > reserved entries.  There are other parameters passed, these two are
> > pretty important for example:
>
>
> The thing I don't get is if you expand the RVECENT macro into the code
> wouldn't you get this:
>
> _start:
>    b reset; nop    /* U-boot entry point */


On power on, first instruction that will get executed is  'b reset, nop'. So
code will Jump to reset label
from where actual booting sequence start.


>
>    b reset; nop    /* software reboot */
>
>    b romReserved
>    b romReserved
>
> ....
>
> romReserved:
>    b romReserved
>
> So wouldn't it get stuck in an infinite loop straight away, calling
> romReserved recursively? I'm obviously overlooking something I think.


So romReserved will not get called in normal booting-sequence as code will
jump to 'reset' label.
 In case of some exception 'romReserved' will be called and then board will
struck in while loop.


Thanks,
Chetan  Nanda

>
>
> And what's the point of passing the second parameter (0-127) to RVECENT
> when
> it's not used?
>
> --
> Regards,
> Peter Belm
>
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