Why would yosys need to support the display cell?
Is the thought that there would be an
m.d.comb += Display(f’foo {bar}’}?

And that yosys right now doesnt accept verilog with
Display?

I don’t imagine that yosys has anything useful it could
do with Display except in the case of CXXrtl, so perhaps
Yosys would mostly ignore Display?

Is the thought that there would be an m.d.comb += Display(f’foo {bar}’}?

Yes.

I don’t imagine that yosys has anything useful it could do with Display

It should read and write Verilog with $display statements. Some reasons why that's necessary are:

• LiteX integrates with nMigen through Verilog;
• Using nMigen with iverilog or Verilator.

I'm assuming we wouldn't use f-strings because that evaluates the expressions before passing control to the called function. Something more like m.d.comb += Display(s, *args, **kwargs) which does the equivalent of s.format(args, kwargs) except in $display language?

Also, is there an RTLIL equivalent?

Something more like m.d.comb += Display(s, *args, **kwargs) which does the equivalent of s.format(args, kwargs) except in $display language?

Yep.

Also, is there an RTLIL equivalent?

Not yet, but I'm working on it, like, right now.

Not yet, but I'm working on it, like, right now.

I kinda figured because now I recall the big meows about $display last week on Twitter :D

FWIW I have some WIP here that I'm planning to turn into something neat and PR-able in the coming days.

Support for this feature has been accepted via RFC 50 and implementation is tracked in issue #1186.