[Libre-soc-dev] VERSA_ECP5 JTAG TAP interface confirmed functional

[Jacob Lifshay]

On Sat, Apr 24, 2021 at 3:22 PM Luke Kenneth Casson Leighton
<lkcl at lkcl.net> wrote:
>
> On Saturday, April 24, 2021, Luke Kenneth Casson Leighton <lkcl at lkcl.net>
> wrote:
>
> >
> > gatecat notes that the BRAMs on the 5G version are much faster.  and 256MB
> > SDRAM is about as much as can be pushed with a single SDRAM IC anyway.
> >
>
> 512 mbit is the limit, which is 64 mbytes.
>
> https://www.digikey.co.uk/products/en/integrated-circuits-ics/memory/774?k=&pkeyword=&sv=0&pv142=239386&sf=1&FV=-8%7C774%2C570%7C400795&quantity=&ColumnSort=0&page=1&stock=1&pageSize=25
>
> is that going to be enough, for running linux without drastic surgery?

I'd expect us to be able to run Kazan in 64MB ram, if we use the
cranelift backend (once that's implemented, of course), maybe even run
in a RTOS instead of Linux (benefits of Rust no_std!). I'd be
surprised if we get gccjit or llvm jit to run in 64MB, they're
optimized for multi-gigabytes.

Jacob