I2C/IIC working on RPI4 8GB?

[Emmanuel Vadot]

On Sun, 2 May 2021 11:14:53 +0100
Mark Murray <markm at FreeBSD.org> wrote:

> Hi Mark,
> 
> On 2 May 2021, at 03:58, Mark Millard <marklmi at yahoo.com> wrote:
> > 
> > [I was given a code hint that I've not investigated yet.]
> > 
> > But going in a different direction, based on my default
> > context on the local FreeBSD RPI4B 8 GiByte:
> 
> ... and a whole lot more really helpful diagnosis over several emails.
> 
> Thank you VERY much! it will take me a while to digest this, but digest it I will.
> 
> Ultimately, it would be good for a "make buildworld; make installworld" on an RPi to install the in-source FDT, and for it to be correct, such that it doesn't take some trickier port modification to have a working FDT. This is worth taking on as a project, but I won't get to it very soon.
> 
> M
> --
> Mark R V Murray
> 

 Installing and dtb in the ESP is still WIP but for RPI things are
different.
 We made a decision to use the dtb shipped with the firmware a long
time ago and most of our drivers are made for them.
 I've never looked at how much work (if any) is needed to have the same
functionality when booting with a dtb compiled from
sys/contrib/device-tree.
 One of the main advantage of using the dtb from rpi-firmware is that
someone following a random blog post saying that one should use one
of the overlays provided by the firmware will mostly work (this can
also be a disadvantage if that doesn't work).

-- 
Emmanuel Vadot <manu at bidouilliste.com> <manu at FreeBSD.org>