no dev.cpu on RPI-B

[Kyle Evans]

On Tue, Apr 9, 2019 at 9:47 PM Bernd Walter <ticso at cicely7.cicely.de> wrote:
>
> On Tue, Apr 09, 2019 at 06:44:19PM -0600, Ian Lepore wrote:
> > On Wed, 2019-04-10 at 02:35 +0200, Bernd Walter wrote:
> > > On Wed, Apr 10, 2019 at 09:59:29AM +1000, Peter Jeremy wrote:
> > > > On 2019-Apr-10 00:39:18 +0200, Bernd Walter <
> > > > ticso at cicely7.cicely.de> wrote:
> > > > > I was hoping for dev.cpu.0.temperature as it exists on the Pi3.
> > > > > Is something missing in my setup (using 12-RELEASE kernel from
> > > > > image),
> > > > > or is there no support for that?
> > > >
> > > > I ran into this when I switched from the FreeBSD FDT to the default
> > > > Linux FDT.
> > > > The latter is missing the CPU description.  The fix is to create
> > > > your own
> > > > FDT overlay and get the loader to load it.  There's a similar
> > > > problem with the
> > > > SPI controller.
> > >
> > > Thank you very much.
> > > That makes sense, didn't thought about FDT because it works on a Pi3
> > > with the same 12.0-RELEASE.
> > > I'm already using overlays on those systems for SPI, my own APA102
> > > LED driver
> > > and DS18B20 sensors.
> > > It is for an LED matrix running 24 RPI1 with 800 LEDs each.
> > > The systems are nfsroot, but I think the dtso are loaded from the
> > > micro-SD
> > > cards :-(
> > > Well - I guess I setup a bootscript on the NFS server to update the
> > > data on
> > > the cards.
> > >
> >
> > I think that's true if you use uboot or the config.txt file to load the
> > overlays.  If you set fdt_overlays="file1.dtbo,file2.dtbo,etc" in
> > /boot/loader.conf the overlays should come from /boot/dtb/overlays in
> > the same /boot folder.
>
> I switch to network via loader.conf:
> [42]matrix# cat /boot/loader.conf
> # Configure USB OTG; see usb_template(4).
> hw.usb.template=3
> umodem_load="YES"
> # Disable the beastie menu and color
> beastie_disable="YES"
> loader_color="NO"
>
> currdev="net0"
>
> fdt_overlays="rpi-apa102-matrix.dtbo"
> #fdt_overlays="spigen-rpi-b.dtbo"
>
> owc_load="YES"
> ow_load="YES"
> ow_temp_load="YES"
> apa102_load="YES"
>
>
> I know that it loads the kernel and modules from network, but the
> loader, the loader.conf and maybe the dtbo files are from the card.
> I couldn't get u-boot to switch to network.
> Well - not a major issue.
> I used an extra UFS partition for that, but it should have also worked
> by placing the files on the msdosfs partition.
> I've copyed the whole /boot over to the UFS, but that's more than
> required.
>

DTBO should be getting loaded from the same device that your
kernel/kmods are- it does (...as of the last time I touched it) what
is effectively `load -t dtbo $filename` for every file in your
fdt_overlays.