[Skiboot] [RFC PATCH 4/7] external/common: Add POWERPC code reenable building pflash for POWER

Joel Stanley joel at jms.id.au
Tue Aug 4 12:12:23 AEST 2015


On Tue, Aug 4, 2015 at 11:14 AM, Alistair Popple <alistair at popple.id.au> wrote:
>> > Did we ever use xscom? I think you mean LPC.
>>
>> Maybe....
>
> The LPC bus is accessed via scom registers, so you're both right. I believe
> pflash used to access the LPC bus via poking at scom registers using the xscom
> debugfs interface. In reality the scom registers are actually used to access
> the OPB bus which is what the LPC bus is connected to on the host.

Yeah. pflash would use the lpc debugfs interface which the kernel
turned into opal calls, and then skiboot would do the poking of the
scom registers for us.

Do you think we should add another layer of abstraction?

Joel


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