[U-Boot] [PATCH v3] Add "cpu_config" command for PPC4xx bootstrap configuration

Stefan Roese
2009-07-19T17:03:06Z

On Sunday 19 July 2009 13:23:49 Matthias Fuchs wrote:
> > > Either we use eeprom_write() or we use multiple call of i2c_write().
> > > If we do not change this, Stefan's code does not work with 405EP cpus.
> > > On these you have 0x20 strapping bytes and typicall EEPROMs with 8 or
> > > 16 bytes pagesize (24W01/02/04/08/16).
> >
> > I see. So we should probably enable and export eeprom_write() in this
> > case, and then use it.
>
> I see no other way.
>
> Stefan, could you then please also a a further CONFIG option
> "CONFIG_4xx_CONFIG_I2C_EEPROM_OFFSET" to give a starting address of the
> bootstrap data inside the EEPROM other than 0. On some 4xx CPUs you can
> select between different EEPROM offsets by external CPU pins. So bootstrap
> data could start at an address other than 0. It could also be helpful to
> pass this address somehow to the cpu_config during runtime. Let's say you
> have a 405EP based PCI adapter board that my use 33 or 66MHZ PCI clock
> dependant from the PCI M66EN signal. You could use that signal to make the
> bootstrap controller select between two configurations. In this case to
> have to call cpu_config on two EEPROM ranges with diffenrent arguments.
>
> But to get cpu_config finally done, please add the _OFFSET option and I am
> happy. It could have a default of 0.

OK, I'll try wrap up a new patch version tomorrow which uses eeprom_write() if
available and this new ..._EEPROM_OFFSET define. And then let's please get
this patch in. We can always add functionality later on.

Best regards,
Stefan

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