Hi Tomek, I know that the .elf files and fixup4.dat are necessary for initializing the GPU firmware, although some of the other device tree files may be unnecessary. I didn't try experimenting with removing any of them or looking into it to much; my experience with the Pi 4B is that both Raspberry Pi's Linux distribution and QNX use these files on the boot partition, however they might actually be incorporating device trees into their kernel, whereas NuttX uses a re-compile approach when selecting which device drivers to load. I think some of these files might not be necessary in actuality, like the `bcm2711-rpi-4-b.dtb`, but I haven't tested that yet. Good point!
Matteo On Tue, Dec 17, 2024 at 09:09:46PM +0100, Tomek CEDRO wrote: > On Tue, Dec 17, 2024 at 7:35 PM Matteo Golin <matteo.go...@gmail.com> wrote: > > Hi Tomek, > > Although some of the specs between the two boards are similar, the Pi Zero > > 2W uses the RP3A0 chip from what I can tell, > > while the Raspberry Pi 4B uses the BCM2711. The RP3A0 uses the same silicon > > die from the BCM2837. I don't think the code > > will work on both, although they are both quad-core Arm A53 cores so maybe > > my porting guide from the BCM2711 along with > > Lup's work on the Pinephone will help others bring up NuttX on this chip. > > It's also possible some things can be reused > > between chips (I assume Broadcom uses the same registers for most of their > > I2C interfaces, for instance), but I haven't > > investigated this. > > Very cool, thank you Matteo! The big problem now is the time to find > to play with it :-) > > I can see we also depend on *.dtb and *.dat files that are somehow > PITA on other OS (i.e. FreeBSD) as the DTS standard changes often it > is hard to follow changes and find versions that allow run provided > pre-built images.. > > What are your experiences in this field? Are these files really > necessary? Is it part of UBoot configuration? > > > > I have included indications in the supported platform documentation about > > what features are completely, partially > > complete or missing completely, it just appears that the documentation has > > not updated with the changes yet. It should > > be visible tomorrow when the next build runs. > > Sorry I did not watch the PR I was on delegation and getting back to > the living.. the website is now updated :-) > > https://nuttx.apache.org/docs/latest/platforms/arm64/bcm2711/boards/raspberrypi-4b/index.html > > Thank you :-) > Tomek > > -- > CeDeROM, SQ7MHZ, http://www.tomek.cedro.info -- Matteo Golin
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