Thanks Tomek! That would be a good resource.

On Wed, Oct 22, 2025 at 7:29 AM Tomek CEDRO <[email protected]> wrote:

> OpenBSD 7.8 has been just released and it has official support for rPI
> 5 with all sorts of peripherals.. maybe this is the new source to look
> for drivers code? :-)
>
> https://ftp.openbsd.org/pub/OpenBSD/7.8/arm64/INSTALL.arm64
>
> https://cvsweb.openbsd.org/src/
>
> Have a good day :-)
> Tomek
>
> On Tue, Sep 16, 2025 at 5:22 PM Matteo Golin <[email protected]>
> wrote:
> >
> > Thanks Alan! Maybe I will reach out to Arasan, could have more luck than
> > with Broadcom, but I doubt it.
> >
> > I'll take a look at these documents!
> >
> > Thanks again,
> > Matteo
> >
> > On Tue, Sep 16, 2025, 11:00 AM Alan C. Assis <[email protected]> wrote:
> >
> > > Hi Matteo,
> > >
> > > Please that a look:
> > > https://www.arasan.com/products/sd-emmc/sdio-3-0-device/
> > >
> > > There is an option to Download (request) the Datasheet from that page,
> but
> > > you can access it directly here:
> > >
> > >
> https://www.arasan.com/wp-content/uploads/2016/05/3MCR-Total-IP-Solution.pdf
> > >
> > > This document is more about the IP core details, but could give you
> more
> > > understanding about internal block of the SDIO controller (its FIFO,
> > > initialization diagram, etc)
> > >
> > > You can also try to find the original
> > > SD3.0_Host_AHB_eMMC4.4_Usersguide_ver5.9_jan11_10.pdf cited in
> Raspberry
> > > documentation.
> > >
> > > BR,
> > >
> > > Alan
> > >
> > >
> > >
> > > On Tue, Sep 16, 2025 at 11:17 AM Matteo Golin <[email protected]>
> > > wrote:
> > >
> > > > Hi Alan,
> > > >
> > > > Thank you for the tips! Yes, SDIO looks pretty involved compared to
> SPI
> > > or
> > > > I2C. I'll try reading the specification like you suggested.
> > > >
> > > > The BCM2711 datasheet doesn't document it at all, however the EMMC
> > > > interface is supposedly the exact same from the BCM2835 and the
> registers
> > > > there are at least documented. All I know is that it is using an
> > > interface
> > > > by Arasan. I'm not as familiar with NuttX, but if this at all looks
> like
> > > > something that's already been supported, please let me know. In the
> > > > meantime, I'll look through the SDIO implementations to check:
> > > >
> > >
> https://www.raspberrypi.org/app/uploads/2012/02/BCM2835-ARM-Peripherals.pdf
> > > > (page 65)
> > > >
> > > > Thanks again!
> > > > Matteo
> > > >
> > > > On Tue, Sep 16, 2025 at 9:49 AM Alan C. Assis <[email protected]>
> wrote:
> > > >
> > > > > HI Matteo,
> > > > >
> > > > > I implemented the SDIO support for LPC43 some years ago and what
> helped
> > > > me
> > > > > most was reading the SD/MMC specification, the LPC43 reference
> manual
> > > and
> > > > > enabling the NuttX SD/MMC debug messages.
> > > > >
> > > > > There are many details to take care of: clock enable for the
> > > controller,
> > > > > interrupts, pins configuration, etc.
> > > > >
> > > > > Unfortunately, the BCM2711 doc is not good. You can start
> verifying the
> > > > > registers, maybe it is based on some SD/MMC core IP already
> supported
> > > by
> > > > > NuttX.
> > > > >
> > > > > BR,
> > > > >
> > > > > Alan
> > > > >
> > > > >
> > > > >
> > > > > On Mon, Sep 15, 2025 at 6:34 PM Matteo Golin <
> [email protected]>
> > > > > wrote:
> > > > >
> > > > > > Hi everyone,
> > > > > >
> > > > > > Now that I2C has been tackled, I am moving on to SDIO interfaces
> so
> > > the
> > > > > SD
> > > > > > card can be interacted with from NuttX.
> > > > > >
> > > > > > The NuttX SDIO documentation is a little bare, and I'm not the
> most
> > > > > > familiar with SDIO. Does anyone have any recommendations for
> > > > > > implementations to look at (besides the STM32 one that is linked
> in
> > > the
> > > > > > docs), resources to read (any blog posts from when you ported
> SDIO)
> > > or
> > > > > > advice in general? It would be much appreciated.
> > > > > >
> > > > > > Thank you,
> > > > > > Matteo
> > > > > >
> > > > > > On Fri, Sep 5, 2025, 11:15 AM Matteo Golin <
> [email protected]>
> > > > > wrote:
> > > > > >
> > > > > > > Got another response from my earlier request to Raspberry Pi
> > > through
> > > > > > their
> > > > > > > website:
> > > > > > >
> > > > > > > Hi Matteo
> > > > > > >
> > > > > > >
> > > > > > >
> > > > > > >> Thanks for getting in touch. We don't actually have any more
> > > > > > >> documentation that we can release on this. My usual
> recommendation
> > > > is
> > > > > > for
> > > > > > >> SW people to take a look at the Linux drivers to get a closer
> > > > > > understanding
> > > > > > >> of how the HW works. Not ideal, but the best I can offer.
> > > > > > >
> > > > > > >
> > > > > > > So I guess everyone is telling us the same thing!
> > > > > > >
> > > > > > >
> > > > > > > On Mon, Sep 1, 2025 at 3:49 PM Tomek CEDRO <[email protected]>
> > > wrote:
> > > > > > >
> > > > > > >> Sure! Public now :-)
> > > > > > >> Tomek
> > > > > > >>
> > > > > > >> On Mon, Sep 1, 2025 at 9:24 PM Matteo Golin <
> > > [email protected]
> > > > >
> > > > > > >> wrote:
> > > > > > >> >
> > > > > > >> > I have populated the RPi 4B project with some starting
> issues to
> > > > > > tackle
> > > > > > >> for
> > > > > > >> > the 4B implementation. I see that the project is marked as
> > > > private;
> > > > > is
> > > > > > >> > there any way to make it visible to potential contributors
> just
> > > > > > visiting
> > > > > > >> > the GitHub page? I think if they can see a list of issues
> in one
> > > > > place
> > > > > > >> when
> > > > > > >> > they go to the page it might help.
> > > > > > >> >
> > > > > > >> > Thanks,
> > > > > > >> > Matteo
> > > > > > >> >
> > > > > > >> > On Mon, Sep 1, 2025 at 3:02 PM Tomek CEDRO <
> [email protected]>
> > > > > wrote:
> > > > > > >> >
> > > > > > >> > > Thank you Linguini, good luck and have fun! :-)
> > > > > > >> > > Tomek
> > > > > > >> > >
> > > > > > >> > > On Mon, Sep 1, 2025 at 8:48 PM Matteo Golin <
> > > > > [email protected]
> > > > > > >
> > > > > > >> > > wrote:
> > > > > > >> > > >
> > > > > > >> > > > To update the community, we've been told by Gordon that
> the
> > > Pi
> > > > > > >> Foundation
> > > > > > >> > > > doesn't have any documentation for the chip beyond what
> was
> > > > > > written
> > > > > > >> in
> > > > > > >> > > the
> > > > > > >> > > > peripheral datasheet. Broadcom themselves has written
> the
> > > > Linux
> > > > > > >> drivers
> > > > > > >> > > and
> > > > > > >> > > > Raspberry Pi has only made some slight bug fixes, etc.
> We've
> > > > > been
> > > > > > >> > > suggested
> > > > > > >> > > > to read the source to discover undocumented
> > > > > > registers/configuration
> > > > > > >> > > options.
> > > > > > >> > > >
> > > > > > >> > > > I plan to still continue with the port until the
> feature set
> > > > on
> > > > > > >> NuttX is
> > > > > > >> > > > equal or greater to what is available on QNX. I at least
> > > want
> > > > to
> > > > > > get
> > > > > > >> > > > Ethernet and some graphics running after the base
> peripheral
> > > > set
> > > > > > >> (I2C,
> > > > > > >> > > SPI,
> > > > > > >> > > > UART) are supported.
> > > > > > >> > > >
> > > > > > >> > > > Matteo
> > > > > > >> > > >
> > > > > > >> > > > On Sun, Aug 31, 2025 at 6:10 PM Matteo Golin <
> > > > > > >> [email protected]>
> > > > > > >> > > wrote:
> > > > > > >> > > >
> > > > > > >> > > > > Very interesting Sebastian. I got that impression from
> > > > > Broadcom
> > > > > > >> when I
> > > > > > >> > > was
> > > > > > >> > > > > initially trying to port NuttX to the Pi. The
> inability to
> > > > > > submit
> > > > > > >> > > forms on
> > > > > > >> > > > > their website seems like it might be by design...
> > > > > > >> > > > >
> > > > > > >> > > > > I'm hopeful the Raspberry Pi Foundation will have
> > > something
> > > > > more
> > > > > > >> for
> > > > > > >> > > us to
> > > > > > >> > > > > work with, they seem more positive to FOSS. Otherwise
> I
> > > will
> > > > > > still
> > > > > > >> > > continue
> > > > > > >> > > > > with reverse engineering until at least the point
> where
> > > the
> > > > > > >> > > functionality
> > > > > > >> > > > > driver-wise is on par with QNX.
> > > > > > >> > > > >
> > > > > > >> > > > > On Sun, Aug 31, 2025, 10:46 AM Tomek CEDRO <
> > > > [email protected]>
> > > > > > >> wrote:
> > > > > > >> > > > >
> > > > > > >> > > > >> James Dougherty contacted us with Gordon Hollingworth
> > > from
> > > > > > >> Raspberry
> > > > > > >> > > > >> Pi Foundation recently :-) We are waiting for
> response
> > > :-)
> > > > I
> > > > > > >> really
> > > > > > >> > > > >> hope we can get some sort of documentation and/or
> code
> > > > > samples
> > > > > > to
> > > > > > >> > > > >> write high quality NuttX port for the big
> raspberries :-)
> > > > > > >> > > > >>
> > > > > > >> > > > >> Open-Source matters even more in this crazy world.
> Thanks
> > > > for
> > > > > > >> > > > >> interesting article Sebastien! Personally I think we
> > > should
> > > > > > >> focus only
> > > > > > >> > > > >> on vendors that support Open-Source. What is the
> reason
> > > for
> > > > > > >> bumping
> > > > > > >> > > > >> sales for companies that in the end can sue you for
> > > > > reversing?
> > > > > > :D
> > > > > > >> > > > >>
> > > > > > >> > > > >> Have a good day folks :-)
> > > > > > >> > > > >> Tomek
> > > > > > >> > > > >>
> > > > > > >> > > > >>
> > > > > > >> > > > >>
> > > > > > >> > > > >> On Sun, Aug 31, 2025 at 10:15 AM Sebastien Lorquet <
> > > > > > >> > > [email protected]>
> > > > > > >> > > > >> wrote:
> > > > > > >> > > > >> >
> > > > > > >> > > > >> > Hello,
> > > > > > >> > > > >> >
> > > > > > >> > > > >> > I just found this interesting document:
> > > > > > >> > > > >> >
> > > > > > >> > > > >> >
> > > > > > >> > > > >>
> > > > > > >> > >
> > > > > > >>
> > > > > >
> > > > >
> > > >
> > >
> https://fastcode.io/2025/08/30/the-69-billion-domino-effect-how-vmwares-debt-fueled-acquisition-is-killing-open-source-one-repository-at-a-time/
> > > > > > >> > > > >> >
> > > > > > >> > > > >> > In a summary, if you expect anything cool from
> > > broadcom:
> > > > > > dont.
> > > > > > >> > > > >> >
> > > > > > >> > > > >> > go go go reverse engineering!
> > > > > > >> > > > >> >
> > > > > > >> > > > >> > Sebastien
> > > > > > >> > > > >> >
> > > > > > >> > > > >> >
> > > > > > >> > > > >> > On 8/29/25 15:37, Tomek CEDRO wrote:
> > > > > > >> > > > >> > > No response from #infra@slack, I just sent
> request
> > > to
> > > > > > >> > > > >> > > [email protected] mailing list maybe someone
> can
> > > > > reply
> > > > > > >> over
> > > > > > >> > > there
> > > > > > >> > > > >> > > :-)
> > > > > > >> > > > >> > >
> > > > > > >> > > > >> > >
> > > > > > >>
> https://lists.apache.org/thread/n9y5vrvjm23npwgbr45f7zq5ys5l8dok
> > > > > > >> > > > >> > >
> > > > > > >> > > > >> > > We should also know the official stance from
> Broadcom
> > > > and
> > > > > > RPI
> > > > > > >> > > > >> Foundation :-)
> > > > > > >> > > > >> > >
> > > > > > >> > > > >> > > Thanks :-)
> > > > > > >> > > > >> > > Tomek
> > > > > > >> > > > >> > >
> > > > > > >> > > > >> > > On Thu, Aug 28, 2025 at 9:35 PM Tomek CEDRO <
> > > > > > >> [email protected]>
> > > > > > >> > > wrote:
> > > > > > >> > > > >> > >> I just asked question at #asfinfra / slack,
> maybe
> > > > > someone
> > > > > > >> can
> > > > > > >> > > help
> > > > > > >> > > > >> > >> there or recommend someone who can, waiting for
> > > > response
> > > > > > :-)
> > > > > > >> > > > >> > >>
> > > > > > >> > > > >> > >> For a good start you can contact Broadcom and
> > > > > RaspberryPi
> > > > > > >> > > Foundation,
> > > > > > >> > > > >> > >> introduce yourself as Apache NuttX RTOS
> developer
> > > that
> > > > > > want
> > > > > > >> to
> > > > > > >> > > port
> > > > > > >> > > > >> > >> NuttX to rPI boards, and just ask if DataSheets
> are
> > > > > > >> available
> > > > > > >> > > :-) We
> > > > > > >> > > > >> > >> will know then first hand if this is possible
> or are
> > > > > there
> > > > > > >> any
> > > > > > >> > > > >> > >> problems / requirements :-)
> > > > > > >> > > > >> > >>
> > > > > > >> > > > >> > >> You can ask for 4B and probably Zero-2W SoC
> > > > > documentation
> > > > > > >> these
> > > > > > >> > > seems
> > > > > > >> > > > >> > >> most popular nowadays :-)
> > > > > > >> > > > >> > >>
> > > > > > >> > > > >> > >> Thanks :-)
> > > > > > >> > > > >> > >> Tomek
> > > > > > >> > > > >> > >>
> > > > > > >> > > > >> > >>
> > > > > > >> > > > >> > >>
> > > > > > >> > > > >> > >> On Thu, Aug 28, 2025 at 8:45 PM Matteo Golin <
> > > > > > >> > > [email protected]>
> > > > > > >> > > > >> wrote:
> > > > > > >> > > > >> > >>> Hi Tomek,
> > > > > > >> > > > >> > >>>
> > > > > > >> > > > >> > >>> Thanks so much! I actually hadn't thought of
> that,
> > > > > maybe
> > > > > > we
> > > > > > >> > > could
> > > > > > >> > > > >> ask for
> > > > > > >> > > > >> > >>> help from the foundation. Do you know who's the
> > > best
> > > > > > point
> > > > > > >> of
> > > > > > >> > > > >> contact for
> > > > > > >> > > > >> > >>> that?
> > > > > > >> > > > >> > >>>
> > > > > > >> > > > >> > >>> I know Linux must have received the datasheets
> to
> > > > make
> > > > > > >> > > Raspberry Pi
> > > > > > >> > > > >> OS. No
> > > > > > >> > > > >> > >>> offence to NuttX, but Linux is pretty popular
> in
> > > > > > >> comparison. If
> > > > > > >> > > > >> Broadcom or
> > > > > > >> > > > >> > >>> Raspberry Pi would release us some information
> that
> > > > > would
> > > > > > >> be an
> > > > > > >> > > > >> immense
> > > > > > >> > > > >> > >>> help. I suspect there was some kind of deal
> with
> > > the
> > > > > > Linux
> > > > > > >> group
> > > > > > >> > > > >> but I have
> > > > > > >> > > > >> > >>> no idea. I believe even QNX didn't have access
> to
> > > the
> > > > > > >> datasheets
> > > > > > >> > > > >> and rather
> > > > > > >> > > > >> > >>> just reverse engineered the Linux drivers.
> > > > > > >> > > > >> > >>>
> > > > > > >> > > > >> > >>> Matteo
> > > > > > >> > > > >> > >>>
> > > > > > >> > > > >> > >>> On Thu, Aug 28, 2025, 12:42 PM Tomek CEDRO <
> > > > > > >> [email protected]>
> > > > > > >> > > > >> wrote:
> > > > > > >> > > > >> > >>>
> > > > > > >> > > > >> > >>>> On Tue, Aug 26, 2025 at 10:05 PM Matteo Golin
> <
> > > > > > >> > > > >> [email protected]>
> > > > > > >> > > > >> > >>>> wrote:
> > > > > > >> > > > >> > >>>>> I2C still needs some work unfortunately.
> > > However, I
> > > > > > agree
> > > > > > >> > > with you
> > > > > > >> > > > >> > >>>>> generally. Personally, I think HDMI,
> networking
> > > > > > >> (including
> > > > > > >> > > WiFi
> > > > > > >> > > > >> and BLE)
> > > > > > >> > > > >> > >>>>> and some kind of interaction with storage
> (eMMC
> > > or
> > > > SD
> > > > > > >> card)
> > > > > > >> > > are
> > > > > > >> > > > >> the most
> > > > > > >> > > > >> > >>>>> important. Unfortunately, those are likely
> going
> > > to
> > > > > be
> > > > > > >> the
> > > > > > >> > > most
> > > > > > >> > > > >> difficult
> > > > > > >> > > > >> > >>>>> because of the lack of documentation on the
> > > > > > peripherals.
> > > > > > >> It is
> > > > > > >> > > > >> definitely
> > > > > > >> > > > >> > >>>>> not an impossible task, but it will be
> > > challenging.
> > > > > > >> Hence my
> > > > > > >> > > > >> request for
> > > > > > >> > > > >> > >>>>> creating the new project roadmap, so maybe
> some
> > > > > > >> discoveries
> > > > > > >> > > can be
> > > > > > >> > > > >> > >>>>> documented there and more eyes can get on
> the RPi
> > > > > > >> > > implementation.
> > > > > > >> > > > >> > >>>> The lack of documentation is a real pain, and
> > > known
> > > > > > issue
> > > > > > >> for
> > > > > > >> > > > >> years in
> > > > > > >> > > > >> > >>>> many areas, but some vendors are especially
> famous
> > > > for
> > > > > > >> that.
> > > > > > >> > > > >> > >>>>
> > > > > > >> > > > >> > >>>> Considering someone wants to create
> Open-Source
> > > > > drivers
> > > > > > >> for
> > > > > > >> > > free
> > > > > > >> > > > >> and
> > > > > > >> > > > >> > >>>> bring customers to the vendor.
> > > > > > >> > > > >> > >>>>
> > > > > > >> > > > >> > >>>> Maybe we could ask Apache Foundation for help
> in
> > > > > > obtaining
> > > > > > >> > > required
> > > > > > >> > > > >> > >>>> datasheets? :-)
> > > > > > >> > > > >> > >>>>
> > > > > > >> > > > >> > >>>> --
> > > > > > >> > > > >> > >>>> CeDeROM, SQ7MHZ, http://www.tomek.cedro.info
> > > > > > >> > > > >> > >>>>
> > > > > > >> > > > >> > >>
> > > > > > >> > > > >> > >>
> > > > > > >> > > > >> > >> --
> > > > > > >> > > > >> > >> CeDeROM, SQ7MHZ, http://www.tomek.cedro.info
> > > > > > >> > > > >> > >
> > > > > > >> > > > >> > >
> > > > > > >> > > > >>
> > > > > > >> > > > >>
> > > > > > >> > > > >>
> > > > > > >> > > > >> --
> > > > > > >> > > > >> CeDeROM, SQ7MHZ, http://www.tomek.cedro.info
> > > > > > >> > > > >>
> > > > > > >> > > > >
> > > > > > >> > >
> > > > > > >> > >
> > > > > > >> > >
> > > > > > >> > > --
> > > > > > >> > > CeDeROM, SQ7MHZ, http://www.tomek.cedro.info
> > > > > > >> > >
> > > > > > >>
> > > > > > >>
> > > > > > >>
> > > > > > >> --
> > > > > > >> CeDeROM, SQ7MHZ, http://www.tomek.cedro.info
> > > > > > >>
> > > > > > >
> > > > > >
> > > > >
> > > >
> > >
>
>
>
> --
> CeDeROM, SQ7MHZ, http://www.tomek.cedro.info
>

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