Re: [ECOS] vectors.s

["Rupesh S" <rupeshs at myw dot ltindia dot com>]

thanks for the clue...

the board flash is mapped for 0x8000000, and the mapping is done at an
initialization code for chip select registers which is apart from the RESET.
The reset vector for SH3 is hooked at 0xA0000000, and the code is linked at
0x80000000. So changing the PC with a value other than 0xA0xxxxxx, would not
provide the appropriate chip selects untill the chipselect registers are
initialized.....

I find that the MMU initializations are commented off.
Out of curiosity ,,,Is it not feasible to handle the MMU related stuff at
the bootloader level ??
Rupesh

----- Original Message -----
From: "Jonathan Larmour" <jifl at eCosCentric dot com>
To: "Rupesh S" <rupeshs at myw dot ltindia dot com>
Cc: "Andrew Lunn" <andrew dot lunn at ascom dot ch>; <ecos-discuss at sources dot redhat dot com>
Sent: Thursday, April 17, 2003 6:53 AM
Subject: Re: [ECOS] vectors.s


> Rupesh S wrote:
> > thanx for the info...
> > As u said, the content of _reset_platform is data (the address of
> > __reset_platform , which is in vectors.S , and does the hardware
inits...).
> > May be the dissambler would have interpreted the address as a match of
the
> > bra instruction. I was reading that fluke code.
> > Good leason not to rely on the disassembled code....!!!
> >
> > I have yet another doubt regarding the same...
> > if the startup is ROM , then the data there is address of
> > __reset_platform+0x20000000, why is it done like that...??
>
>  From the comments I guess 0x80000000 is the address the app is linked at
> to run, but in fact is a mapped (and maybe also cached region), but the
> mappings haven't been set up yet, whereas 0xa0000000 will work regardless.
> Maybe :-). I'm sure an SH3 CPU manual should help.... go to the SuperH
site.
>
> Jifl
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