[U-Boot-Users] Altera Stratix II

[eran liberty]

Both of you (Wolfgang and Brent) Provided me with some new angle to think of...

I believe I will prefare crippling the CFI over Crippling the flash
eeprom as I believe it will be easier on our production team... But I
will have to play with it some more...

In the past I had my own flag I called CONFIG_FORCE_FLASH SIZE.
Suppose I will come with a way to cripple the CFI to work as it should
in the latest version, would you like such a feature integrated in the
u-boot for all?

Liberty

On Sat, Mar 1, 2008 at 1:55 AM, Wolfgang Denk <wd at denx.de> wrote:
> In message <ffc2b1d40802291336s78a050b7i780fe48b9f2671ce at mail.gmail.com> you wrote:
> >
> > > I think what you're trying to do is fundamentally broken.  Why  don't
> > > you  use  the  real sizes present on the hardware? Why do you want to
> > > lie to yourself and to your users?
> >
> > I have more then one way to answer this question some are more
> > philosophical then others, But I will choose the bare hardware
> > approach... we "hide" some backup information on the flash. We make
> > sure the user can not access this hiden info by physically lifting the
> > flash legs (there is a programmable part between the flash and the cpu
> > on the bus). So though there may be a 64Mb flash the user really have
> > a 32Mb. It is, in fact, the flash eeprom which lies to the u-boot /
> > linux.
>
> I see.
>
> > Any attempt to access these non existing address will lead to bus
> > fault exactly as if the flash was a 32Mb (which in many sense it is).
> > So, again, it is important for me to tell u-boot "go ahaed and use
> > CFI, but dont listen to the eeporm cuz he doesn't know what he is
> > talking about".
>
> I understand what you are trying to do, but I think  your  conclusion
> is  wrong.  The  CFI  driver was implemented to read the geometry and
> size information from the flash chips; if the  chips  cannot  provide
> the  correct  information  (as in your case), they are simply not CFI
> conformant, and you cannot use the CFI driver.
>
> It may be possible to modify (or cripple) the CFI  driver  to  ignore
> the information provided by the flash chips, or to overwrite parts of
> this  information  (you  would  have  to  overwrite at least size and
> number of sectors [and eventually the start address and first  sector
> offset  if  you  map the flash at a fixed end address]) - but I don't
> think that makes sense.
>
> Best regards,
>
> Wolfgang Denk
>
> --
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