Re: Xen 4.14.1 on RPI4: device tree generation failed

[Tamas K Lengyel <tamas.k.lengyel@xxxxxxxxx>]

On Sun, Jan 31, 2021 at 8:59 PM Elliott Mitchell <ehem+xen@xxxxxxx> wrote:
>
> On Sun, Jan 31, 2021 at 06:50:36PM -0500, Tamas K Lengyel wrote:
> > On Sun, Jan 31, 2021 at 6:33 PM Elliott Mitchell <ehem+undef@xxxxxxx> wrote:
> > >
> > > On Sun, Jan 31, 2021 at 02:06:17PM -0500, Tamas K Lengyel wrote:
> > > > (XEN) Unable to retrieve address 0 for 
> > > > /scb/pcie@7d500000/pci@1,0/usb@1,0
> > > > (XEN) Device tree generation failed (-22).
> > >
> > > > Does anyone have an idea what might be going wrong here? I tried
> > > > building the dtb without using the dtb overlay but it didn't seem to
> > > > do anything.
> > >
> > > If you go to line 1412 of the file xen/arch/arm/domain_build.c and
> > > replace the "return res;" with "continue;" that will bypass the issue.
> > > The 3 people I'm copying on this message though may wish to ask questions
> > > about the state of your build tree.
> >
> > I'll try that but it's a pretty hacky work-around ;)
>
> Actually no, it simply causes Xen to ignore these entries.  The patch
> I've got ready to submit to this list also adjusts the error message to
> avoid misinterpretation, but does pretty well exactly this.
>
> My only concern is whether it should ignore the entries only for Domain 0
> or should always ignore them.
>
>
> > > Presently the rpixen script is grabbing the RPF's 4.19 branch, dates
> > > point to that last being touched last year.  Their tree is at
> > > cc39f1c9f82f6fe5a437836811d906c709e0661c.
> >
> > I've moved the Linux branch up to 5.10 because there had been a fair
> > amount of work that went into fixing Xen on RPI4, which got merged
> > into 5.9 and I would like to be able to build upstream everything
> > without the custom patches coming with the rpixen script repo.
>
> Please keep track of where your kernel source is checked out at since
> there was a desire to figure out what was going on with the device-trees.
>
>
> Including "console=hvc0 console=AMA0 console=ttyS0 console=tty0" in the
> kernel command-line should ensure you get output from the kernel if it
> manages to start (yes, Linux does support having multiple consoles at the
> same time).

No output from dom0 received even with the added console options
(+earlyprintk=xen). The kernel build was from rpi-5.10.y
c9226080e513181ffb3909a905e9c23b8a6e8f62. I'll check if it still boots
with 4.19 next.

Tamas