Re: [LinuxBIOS] Read SPD issue

[Joseph Smith]

Quoting Corey Osgood :
> Joseph Smith wrote:
> > Quoting Corey Osgood :
> > > > So, I tried the
> > > >     dump_spd_registers(&memctrl[0]);
> > > >     dump_smbus_registers();
> > > > from debug.c and here is the results:
> > > >
> > > > LinuxBIOS-2.0.0.0Fallback Sat Aug 11 21:37:10 EDT 2007 starting...
> > > >
> > > > dimm: 00.0: 50
> > > > 00: bad device
> > > >
> > > > dimm: 01.0: 51
> > > > 00: bad device
> > > > smbus: 69
> > > >
> > > > HELP???
> > > >
> > > > Thanks - Joe
> > >
> > > In the attached debug.c is probe_spd_rom(). If your device has spd, it
> > > should be able to find it. You can use the whole file and #include it
> > > into the southbridge or mainboard or even northbridge code, or just copy
> > > and paste it into somewhere else. Call it whereever you called
> > > dump_spd_registers from. Note that it's not magic (yet), it won't
> > > actually use found spd locations, you'll have to do that manually. Also,
> > > what make/model is your dimm and board (I know you've told me, but my
> > > memory is terrible)? The datasheets may have more info, if they're
> > > available.
> > >
> > > -Corey
> >
> > So I tried the probe_spd_rom() and it comes back with "bad device".
>
> That's because I messed up and forgot to remove the break, so after
> checking the first location, it left the function. It should have (quite
> literally) filled your screen with bad device messages, with one message
> saying it found an spd rom. In hindsight, it was pretty damn stupid of
> me to leave that message there. Try the attached version, it should be
> fixed and is even simpler now.
> > Which I expected because this line in the function
> >
> > status = smbus_read_byte(i, 0);
> >
> > is my whole problem:( The smbus_read_byte function is what is not
> > working in raminit.c so why would it work when called from auto.c?? No
> > matter what byte I try to read it just comes back with a 0xFF ??
> >
> > Here is a recap of the hardware:
> > RCA RM4100 Embedded Set-top-box
> > Low Voltage Intel® Celeron® processor (Micro-FC-BGA) 733MHz
> > 128MB PC133 SDRAM on board (Embedded) (In Socket2)
> > Intel i82830 (i830M4) Northbridge (Developing)
> > Intel i82801DB Southbridge (Using i82801xx)
> > SMSC lpc47m192 SuperIO (Using smscsuperio)
> >
> > This is making me crazy, I'm so confused?
> >
> > Thanks - Joe
>
> Essentially what seems to be going on here is the smbus is looking for
> data, but it can't find the spd rom. The "bad device" error is trying to
> say bad spd device, or at least that's the hope. Better parsing of the
> error code (-1 vs -2, etc) could tell us more, but that's the next step
> (mainly cuz I'm almost asleep right now). This is exploring stepan's
> theory that the device isn't located at the standard 0x50, etc, by
> checking the first byte (byte 0) at every address (denoted by i),
> through the first 256, and throwing up a message if it finds anything.
> Note that just because there's a device found it's not necessarily the
> spd rom, but there's a decent chance of it. The other possible problem
> is that, since your ram is embedded, there isn't any spd rom at all...
>
> -Corey

Ok, so I tried this and it just returns a "SPD located at 0x69" is  
this correct?
It is much different than the standard 0x50, etc. Is this because it  
is embedded?? Thanks for all help.

Thanks - Joe