[flashrom] [coreboot] Dualbios on GA-MA770-UD3

[Stefan Tauner]

On Fri, 09 Apr 2010 19:08:21 +0400
vadimgirlin at gmail.com (Vadim Girlin) wrote:

> On 04/09/2010 04:18 PM, Carl-Daniel Hailfinger wrote:
> > Hi Vadim,
> >
> > thanks for your mail. I have added the flashrom mailing list in CC:
> > because we should develop a generic way to handle DualBIOS and similar
> > techniques.
> >
> > On 09.04.2010 08:12, Vadim Girlin wrote:
> >   
> >> I'm going to try coreboot on Gigabyte GA-MA770-UD3.
> >> It's AMD 770 (RX780 / SB700).
> >>
> >> My motherboard supports hardware dual bios - with two chips on it.
> >> I'm going to try flashing backup chip and boot from it. It seems to be
> >> possible - I've tested it (flashing at least). Chips on this board could
> >> be switched by changing bit 0 at undocumented register EF on LDN 7 of
> >> IT8720. I can use slightly patched flashrom for accessing any chip I
> >> want without any problems. And this is tested many times.
> >>
> >> My idea is to use backup chip for debugging - that always keeps my
> >> chance to reboot from main bios chip. And removes the need for
> >> desoldering etc.
> >>
> >> And second problem is that original bios is checking second chip - and
> >> trying to recover it by flashing the bios from main chip on reboot?
> >> rewriting coreboot. AFAICS this could be solved by including some
> >> signatures etc. It seems to be easy to find out. May be someone is
> >> working on this?
> >>
> >> BTW I can send the patch for flashrom - but I think that with
> >> information I mentioned above somebody could make it much better than my
> >> ugly hack. I hope the regs should be the same for all latest Gigabyte
> >> MBs using IT8720/18
> >>   
> >>     
> > It would be great if you could send that patch. It will help us make a
> > flashrom design decision that works for all boards with multiple flash
> > chips.
> >
> >   
> OK, I'm sending the patch for flashrom - but it is based on RE and needs
> careful testing.
> It works fine on GA-MA770-UD3 (rev 1.0) but should be tested with other MBs.
> Anyway I hope it should work for all latest Gigabyte MBs with dual bios
> chips connected through IT8720/18.
> I think it's not ready for inclusion in flashrom - it probably should be
> done in more safe and generic way.
> Probably it should check for default values in regs etc.
> 
> It may be used as following:
> 
> flashrom -p it87spi:gbdualindex=0 ...
> flashrom -p it87spi:gbdualindex=1 ...
> 
> This value needs to be set only once and further ops on selected chip
> can be performed without parameters.
> 
> Index: it87spi.c
> ===================================================================
> --- it87spi.c	(revision 992)
> +++ it87spi.c	(working copy)
> @@ -155,6 +155,28 @@
>  				sio_write(port, 0x65, (flashport & 0xff));
>  				free(portpos);
>  			}
> +
> +			portpos = extract_param(&programmer_param,
> +						"gbdualindex=", ",:");
> +			if (portpos) {
> +				int chip_index = strtol(portpos, (char **)NULL, 0);
> +				if ((chip_index!=0) && (chip_index!=1))	{
> +					msg_perr("Dual bios: Invalid chip index requested: %d\n",chip_index);
> +					flashport=0;
> +				} else {
> +					tmp=sio_read(port,0xEF);
> +					msg_pinfo("Dual bios: Current chip : %d\n",tmp&1);
> +					if (chip_index!=(tmp&1)) {
> +						sio_write(port,0xEF,(tmp&0xFE)|chip_index);
> +						tmp=sio_read(port,0xEF)&1;
> +						if (tmp!=chip_index) {
> +							msg_perr("Dual bios: Chip selection failed.\n");
> +							flashport=0;
> +						} else msg_pinfo("Dual bios: Selected chip: %d\n",tmp&1);
> +					}
> +				}
> +				free(portpos);
> +			}
>  		}
>  		exit_conf_mode_ite(port);
>  		break;

Hello Vadim!

Someone has tested a refinement of your patch with an ITE 8728 and it
(still) worked fine. I'd like to request a sign-off from you in case we
want to eventually integrate it. (see
http://www.coreboot.org/Development_Guidelines#Sign-off_Procedure for details).
Thanks!

-- 
Kind regards/Mit freundlichen Grüßen, Stefan Tauner