[LinuxBIOS] m57sli : debugging the flashrom problem when booting with LB
Carl-Daniel Hailfinger
c-d.hailfinger.devel.2006 at gmx.net
Thu Jan 10 13:42:41 CET 2008
On 10.01.2008 12:14, Florentin Demetrescu wrote:
> Hi all,
>
> I started working on this problem this week and there are some strange things I
> have found so far.
>
Thanks for trying to figure this out!
> First, the behaviour I noticed when starting flashrom after booting whith LB :
> 1) flashrom needs to be given the board type in command line parameter (-m
> gigabyte:m57sli) otherwise it is unable to recognize this board. On the other
> hand it seems to correctly recognize the SB type (mcp55) and the SIO too
> (it8716). It seems that it succeeds in reading and writting the configuration
> registers of the SIO (those accesible through the 0x2e - 0x2f pair of IO ports)
> at least..
>
It seems the board identifiers used inside LB and inside flashrom differ.
> 2) the real problem is that it hangs when trying to access the SPI interface of
> the SIO, more precisely when pooling the "busy flag" of the configuration
> register of the SPI interface before sending a SPI command, normally mapped at
> the 0x820 IO address. Indeed when dumping the value which is read @ this
> address, one get a value 0xff! It doesn't seem to me that this register should
> have normally this value, there seem to be a problem with the decoding of this
> IO address range into the mcp55 SB very probably..
>
Yes indeed.
> 3) the most strange thing is that when probing with an oscilloscope the SPI
> signals, there _IS_ indeed a burst of activity on the CLK line when executing
> flashrom. Some code into flashrom seems to generate this activity, but I haven't
>
That's the classic parallel flash probing which reads from and writes to
the memory area of the chip.
> found so far where it is triggerd. But from the flashrom point of view there is
> no reponse from the spi interface so it hangs..
>
Yes, that's the SPI probing which waits on the status register as you said.
> Rudolf Marek suggested after an irc discussion that there could be problems with
> the GPIO configuration, but I don't think so, because if that would be the case
> then we couldn't access the SIO at all and the platform wouldn't boot at all
> with LB. But who knows? Rudolf, can you be more specific about this GPIO
> hypothesis?..
> For my part I continue to think that there is a problem with the IO address
> decoding into the PCI->LPC bridge in mcp55.. Yinghai, can you help please?
>
Yinghai? Is there some mcp55 conf we need to change?
Regards,
Carl-Daniel
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