[okl4-developer] More NSLU2 debugging

[Geoffrey Lee]

On Sun, Jun 22, 2008 at 07:42:35PM +1000, Joshua Root wrote:
>
> So you'd expect something like:
>
> add_mapping_init( kspace_phys, (addr_t)(XSCALE_DEV_PHYS+CONSOLE_OFFSET),  
> (addr_t)(XSCALE_DEV_PHYS+CONSOLE_OFFSET), uncached );
>
> to work if I do it at the same time as the other 1:1 mappings? And after  
> VM is turned on here (init.cc:353):
>
> /* Enable virtual memory, caching etc */
>     write_cp15_register(C15_control, C15_CRm_default,
>                     C15_OP2_default, C15_CONTROL_KERNEL);
>
> I should be able to write to the UART, yes? (And indeed I can in the  
> simulator...) I've been doing pretty much what you suggest to pinpoint  
> where it's failing, but I can't get any output after that  
> write_cp15_register call. Could kspace_phys be constructed incorrectly?

Yes, I guess something hasn't been constructed properly.  I think if
you turn off the MMU initialization you will actually get a bit 
further - not saying that is the way to move forward, just that
it properly is something that got put into the cpu which it didn't
like.

It might be a good idea to print out the contents of physbase to double
check that it's been patched properly, and also the contents of the
page table etc that you write to the hardware.

>
> - Josh

	-gl

>

--