RPi4B 2711ZPKFSB06C0T parts seen in the wild, 13.0-RELEASE fails to boot on them

[Mark Millard]

On 2021-Apr-18, at 06:32, Denis Ovsienko <denis at ovsienko.info> wrote:
> 
> 
>> The C0T RPi4B should be able to DMA outside
>> the 3 GiByte limit that the B0T ones had: no more
>> limit. The RPi firmware may configure the C0T parts
>> differently and FreeBSD might have changes
>> required if it is to work with the newer parts.
> 
> As far as these commends make sense to me, the foundation has started
> shipping RPI4B revision 1.5,

The 2711ZPKFSB06C0T RPi4B was reported to indicate
revision code b03114 for itself (via attachment
content), which that README.md lists as v1.4:

b03114	4B	1.4	2GB	Sony UK

(The ending hexadecimal digit indicates what
goes after "1." for "new-style revision codes".)

But it turns out that the above line was added to
the table in the same commit as the line:

c03130	Pi 400	1.0	4GB	Sony UK

which is a known 2711ZPKFSB06C0T context. The commit
was back in 2020-Nov. For all I know there may be
b03114's that show a B0T suffix. The shared commit
may be a red herring.

This makes it still unclear if there will be distinct
revision codes in general.

> but forgot to bump the revision number up
> and to update

It is a possibility but not a certainty.

> https://www.raspberrypi.org/documentation/hardware/raspberrypi/revision-codes/README.md
> 
> If that's the case, it might be better to solve the problem at the
> source rather than at run time. It may be more effective to raise this
> through the shop, as the foundation does not seem to have a bug tracker.

An interesting point about b03114 being a 2GB
model's revision code is that the DMA limitation
is basically irrelevant since there is < 3 GiByte
of RAM to start with. Fixing the DMA limitation
would not have been the point of having a
2711ZPKFSB06C0T part in this type of context.


===
Mark Millard
marklmi at yahoo.com
( dsl-only.net went
away in early 2018-Mar)