Re: O2 framebuffer problems with install kernel

On Jul 28, 2008, at 5:26 PM, Michael Lorenz wrote:
>
> Not really - as I said, unaligned writes there are silently  
> ignored, unaligned reads just work so you wouldn't get an error  
> either way, just malfunctioning drivers.
> The other driver that might get bitten by this is mec ( the O2's  
> onboard ethernet ) but I don't know if it uses any bits that would  
> be affected, IIRC most of its registers are 32bit aligned to 64bit.

mec works properly.

>
> To test this please do this:
> Look at crmfb_attach(). After mapping the drawing engine's  
> registers (         rv = bus_space_map(sc->sc_iot, 0x15000000,  
> 0x6000, 0, &sc->sc_reh);
>  ) write some random but recognizeable value into one of the  
> drawing engine's TLB registers ( like this: bus_space_write_8(sc- 
> >sc_iot, sc->sc_reh, CRIME_RE_TLB_A, 0x1122334455667788L); ) and  
> read it back a little bit later. If you get the same value you  
> wrote you're fine and I'll have to think of a new way to screw  
> things up, but if you get something like 0x1122334400000000 or some  
> random garbage in the lower 32 bit then that's the problem.
> If you do this right after mapping the registers it should run even  
> on a serial console, the code that checks for firmware setup come  
> later.

Done, it reads back the same value.