[coreboot] r3393 - trunk/util/flashrom

[Stefan Reinauer]

Carl-Daniel Hailfinger wrote:
> On 28.06.2008 19:37, Stefan Reinauer wrote:
>   
>> I was having a cleanup of the whole SPI/LPC bus handling in mind:
>>
>> we have _1_ global variable (per instance of "flashes"?) instead of one
>> per supported chipset.
>>
>> This variable is an ENUM
>>
>> enum flash_bus {
>>    FLASH_BUS_LPC,
>>    FLASH_BUS_ICH7_SPI,
>>    FLASH_BUS_ICH9_SPI,
>>    FLASH_BUS_VIA_SPI,
>>    FLASH_BUS_IT87_SPI
>> }
>>   
>>     
>
> Looks nice. Can we add a bus for those old (29*) parallel flash chips?
> I assume differentiating between LPC and FWH will be difficult because
> FWH is just a LPC variant and some chipsets do not allow us to detect
> FWH/LPC
>   
I don't think it makes much sense to differentiate between 29* types,
lpc and fwh:
The physical bus looks exactly the same from a software perspective;
until after you scanned the bus and know which category the chip you
found belongs to. And then the data is not exactly interesting anymore.

>> I think this matches the physical actualities much better than the
>> design-less hack that is used at the moment. Also the code could be much
>> nicer in many places, as we could use case statements instead of endless
>> if () else if () else if() statements
>>   
>>     
>
> What happens if there is more than one flash bus? Do we call the probe
> functions compatible with the bus once per bus? If we do that, we can
> stop after the first detected chip.
>   
Not necessarily. You can have multiple chips on the same FWH "bus", so
stopping after you find the first chip is not an option.

But, I suggest we consider multiple flash busses once we see that happen
in the real world. At least the ICH is always strapped to either FWH
_or_ SPI.

Stefan


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