[coreboot] [patch] i82810 WIP for fixing VGA and 512MB

[Uwe Hermann]

On Mon, Nov 17, 2008 at 02:58:55PM +0100, Stefan Reinauer wrote:
> Elia Yehuda wrote:
> > Those 2 patches are one step towards having a working Onboard-VGA
> > and 512MB (the max for i810). The raminit.c patch fixes some
> > misconfigurations and probes the DIMMs correctly (all dual-sided are
> > now recognized properly), and also set buffer_strength to handle 2
> > DIMMs although atm this doesn't work. The i82810/northbridge.c patch
> > takes care of allocating Onboard-VGA memory.
> >
> > Signed-off-by: Elia Yehuda <z4ziggy at gmail.com <mailto:z4ziggy at gmail.com>>
> 
> Good work!

Yep, indeed. But please split up the patch in multiple ones, each fixing
one issue. This way they can be tested and reviewed more easily. I suggest
at least one patch for supporting multiple DIMMs and one for VGA
stuff, maybe more...

I'll be able to test the patches this evening...


> > +	val = pci_read_config8(ctrl->d0, DRAMT);
> I suggest using PCI_DEV(0,0,0) instead of the indirection ctrl->d0 all
> over raminit.c.

> That indirection was invented for AMD K8 where in an SMP environment
> there are several memory controllers with several DIMMs attached to
> each. But the i810 definitely only supports a single memory controller,
> and the code can be kept a lot simpler.

Yep, this is probably true for various NBs in v2, e.g. 440BX, i810,
i830, and maybe more. That should be an extra patch though.


> Also, your code only treats single channel configurations. Is the i810
> capable of dual channel operation?
> 
> > -	/* TODO: This needs to be set according to the DRAM tech
> > +	/* TODO: This needs to be calculated according to the DRAM tech
> >   
> Don't think this can really be calculated. Looking at your findings
> below, you should probably use a table for this and look up the correct
> values from the table.

> >  	 * (x8, x16, or x32). Argh, Intel provides no docs on this!
> >  	 * Currently, it needs to be pulled from the output of
> >  	 * lspci -xxx Rx92
> > +	 * here are some common results:
> > +	 * value:   tom:    config:
> > +	 * 0x3356   256MB   1 x 256MB DIMM(s), dual sided
> > +	 * 0x0001   512MB   2 x 256MB DIMM(s), dual sided
> > +	 * 0x77da   128MB   1 x 128MB DIMM(s), single sided
> > +	 * 0x55c6   128MB   2 x 128MB DIMM(s), single sided
> > +	 * 0x3356   128MB   1 x 128MB DIMM(s), dual sided
> > +	 * 0x0001   256MB   2 x 128MB DIMM(s), dual sided

I assume these are gathered from actual hardware on your board? Or did
you find them in the datasheet somewhere?


> > +	/* setting Vendor/Device ids - there must be a better way of doing
> > +	 * this...
> > +	 */
> > +	/* set vendor id */
> > +	val = pci_read_config16(ctrl->d0, 0);
> > +	pci_write_config16(ctrl->d0, 0x2c, val);
> > +	/* set device id */
> > +	val = pci_read_config16(ctrl->d0, 2);
> > +	pci_write_config16(ctrl->d0, 0x2e, val);
> Yes, during pci_set_subsystem_ids in northbridge.c:

Yep, this should definately be moved.

 
Uwe.
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