[Libre-soc-dev] microwatt-libre-soc interoperable verilator snapshots / debugging

[Lauri Kasanen]

On Sun, 9 Jan 2022 12:08:40 +0000
Luke Kenneth Casson Leighton <lkcl at lkcl.net> wrote:

> * assume that up to a certain instruction, microwatt and libre-soc
>   have performed identically
> * run microwatt
> * in verilator c++ do a **FULL** system-wide state dump.  all
>   registers, all TLB entries, everything.
> * terminate the microwatt simulation
> * run libre-soc
> * have verilator RELOAD the entire state and continue executing...
>   ...from where MICROWATT left off.

Why mix microwatt saves at all? It sounds like an unnecessary
complication, requiring many changes to be able to mix and match saves.

That is: if microwatt and libresoc perform identically until instr X,
then just save libresoc state at instr X. When you fix that issue and
hit the next, load that save, and do a new save at the next divergence
point.

No mixing saves necessary, that I can see.

- Lauri