[Libre-soc-dev] running microwatt-5.7 linux kernel on libresoc

[Luke Kenneth Casson Leighton]

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crowd-funded eco-conscious hardware: https://www.crowdsupply.com/eoma68

On Fri, Jan 7, 2022 at 1:26 PM Luke Kenneth Casson Leighton
<lkcl at lkcl.net> wrote:

>                           wr @ 00088a80 do 69626d2c61726368 sel ff hcra.mbi
>
> potentially this is a bug in the linux kernel, but i think it is probably
> sensible to prioritise adding ldst misalignment.

i've started on adding a "second request" mechanism to LoadStore1.
even if this isn't the "source" of the "problem", it will eliminate it from
the diff files (clearly show up an inversion in *hardware* if in fact
it turns out that the 0x600 trap was doing the right thing)

jacob i did like the idea of checking if microwatt has the same error
it's more this:
https://github.com/antonblanchard/microwatt/blob/7fa7b45faa17950de44591f7a73722fdf8a87385/loadstore1.vhdl#L435

if two_words = 1 then align_intr should be set unconditionally.
however, the version of loadstore1.vhdl we're following (one which
does not have a complex 3-stage pipeline) does not have two_words,
this was a later addition.

l.