Subject: Re: issue at the beginning of kernel booting

From: Benjamin Herrenschmidt <[email-masked]>
Date: Fri, 03 Apr 2009 08:54:55 +1100

On Thu, 2009-04-02 at 11:12 -0500, Scott Wood wrote:
> On Wed, Apr 01, 2009 at 08:23:42PM -0700, Sauce.Cheng wrote:
> > > I don't see where you set up a BAT that covers 0xf0000000.
> > 
> > if i have to set up a BAT that cover 0xF0000000. i had a debug with LEDs
> > like that in u-boot code. everything is //normal. 0xF00000000 is the value
> > of CFG_IMMR(CONFIG_SYS_IMMR) that memory map register, it is the phy address
> > and //base //address of all internal regishters, isnt? you mean that if i
> > set BATs, i should not get the phy address like in the //front ?
> 
> I don't quite follow the above, but what I meant is that you need to
> put a mapping in place that covers your LED I/O once you have the MMU on.
> 
> Any mappings that U-boot made will be gone at that point.

Also, f0000000 isn't a very good idea for a hard wired mapping, it will
overlap some kernel stuffs. You should dynamically allocate the virtual
address, or pick something above 0xfff00000 which should be unused iirc.

Ben.