need your advice before new Raspberry Pi purchase

[Ramiro Aceves <ea1abz%gmail.com@localhost>]

Hello,

I am thinking about buying a more powerful Raspberry Pi than my actual 
Raspberry Pi ZeroW. I like very much how NetBSD operating system is 
working although I was a bit dissapointed with WIFI driver for the 
builtin WIFI device, I feel that I can control the OS and it is the OS I 
was looking for, simple and straightforward without bells and whistles.

In general NetBSD works fine in the Pi once you get used to it, 
everything makes sense soon, you fell confortable and why not to say, I 
am in a new world after many years using Linux and needed new 
sensations. On the Zero W WIFI bwfm driver did not work well and 
overcome that buying a USB WIFI dongle with RTL 8188EU chip that works 
almost ok (with no channel switching  in the router). Now I am going to 
use only ethernet network connection so WIFI will not be a problem.


I have been reading https://wiki.netbsd.org/ports/evbarm/raspberry_pi/ 
but information is a bit confusing.

"As of early 2024, NetBSD does not support the Raspberry Pi 5."

Reading that I inmediatly discarded the Raspberry Pi 5 choice. Being 
realistic I think It does not work in NetBSD 10 now and I estimate it 
will not work well for perhaps some years. Life is short, I cannot wait 
and so I think RaspberryPi 4 should be my buying target.


"NetBSD 10"

    "RPI4 general support (but there are issues)"

Seems explained below.


    "RPI4 ethernet (Broadcom GENETv5) (but the man page for genet(4) is 
missing)"

Can I be sure that ethernet will work fine and reliable? Network speed?


    "builtin bluetooth on RPI3 (RPI0W? RPI4?)"

Does bluetooth work on the Pi4?


    "builtin WiFi on RPI0W, RPI3 and RPI4 - bwfm(4)"

Does WIFI bwfm  driver work as badly as in the ZeroW? Not relevant for 
my future use of the Pi 4 cause I will use it through ethernet but that 
will be a bonus, just curious.


    "RPI4 xhci does not work with a straight netbsd-10 install"

I seems that below is the explanation.

    "RPI4 hardware rng does not work with a straight netbsd-10 install"

I seems that below is the explanation.


The following chapter is very confusing for me:


"Issues and Workarounds"
"RPI4 xhci"

"With the netbsd-10 arm64.img on a RPI4 (most of them), the pci driver 
is missing and therefore xhci will not attach, so the USB ports will not 
work. One workaround is to switch to UEFI, but that leads to a 3GB 
memory limit and needing a monitor. Another is to add kernel config. One 
can also add the hardware rng. Adding the following to GENERIC64.local 
results in both working; you likely also need a dtb that includes the 
RNG. \todo Explain why this isn't in GENERIC64 or link to a PR.

GENERIC64

bcm2838pcie* at fdt?                    # STB PCIe host controller
bcm2838rng* at fdt?                     # RPI4 RNG

There is some need to load firmware for the xhci driver, but apparently 
that works, once the above is added"


Does it mean that using  "traditional booting" you end with non working 
USB ports? Will you even end without keyboard? I mainly will use the Pi 
headless via ssh but need the keyboard in the first configuring steps.

After switching to UEFI you will make USB ports work but 8 GB RapberryPi 
will be reduced to 3 GB only with no workaround? What do "needing a 
monitor" mean? Why?
If the fix for USB and rng is recompiling the KERNEL, why is not enabled 
by default in the standard image?


"RPI4 UEFI 3 GB"

"To work around bugs in hardware (that may or may not be fixed in recent 
RPI4) and because not all OSes have workarounds, the UEFI firmware's 
default is to limit RAM to 3GB. NetBSD 10 can be used with more, so this 
needs to be configured in UEFI."

That should be explained more in detail for newcomers.

Last questions:

Do GPIO pins work ok?

Does I2C work? That is important for me cause I plan to read some sensors.

Does HDMI output work or should I use serial console? traditional boot 
vs UEFI difference in this matter?

What is your final opinion about NetBSD in that board? Are there better 
supported boards perhaps?

Many thanks and sorry for so many questions, just I want to be sure that 
I am going to make a good and useful purchase. If I purchase a Rpi 4 
instead of Rpi 5 to have NetBSD support and It does not work ok, it will 
be a absolute nonsense.

I appreciate your work very much and your comments and advice will be 
welcome and very valuable for me.

Thanks in advance.


Ramiro.