[PATCH RFC 2/4] powerpc: Add Microwatt platform

[Nicholas Piggin]

Excerpts from Alistair Popple's message of May 9, 2020 6:36 pm:
> On Saturday, 9 May 2020 5:58:57 PM AEST Nicholas Piggin wrote:
>> Excerpts from Paul Mackerras's message of May 9, 2020 3:02 pm:
>> > Microwatt is a FPGA-based implementation of the Power ISA.  It
>> > currently only implements little-endian 64-bit mode, and does
>> > not (yet) support SMP.
>> > 
>> > This adds a new machine type to support FPGA-based SoCs with a
>> > Microwatt core.
>> 
>> Very cool!
>> 
>> Would there be any point sharing this with the "naked metal" platform
>> Alistair has for booting POWER in L3 without OPAL? Or is it easy enough
>> to have a several different simple 64s platforms?
> 
> It looks pretty similar at the moment, I've been meaning to clean those 
> patches up and send them upstream but Paul has beaten me to it. The main 
> difference so far is how the console is setup. For booting cache contained I 
> was using a device tree pointing at a standard UART driver and enabling the 
> standard OF platform device tree probing.

Well I'd only merge them if you think it makes sense. If the platform is 
a perfectly good abstraction for the differences and merging them would 
just result in painful special cases it wouldn't be worthwhile. It's
clearly not a lot of code.

Thanks,
Nick