Re: [PATCH v3 2/2] ARM: dts: aspeed: Add device tree for Ampere's Mt. Mitchell BMC

[Arnd Bergmann]

On Thu, Aug 18, 2022 at 9:33 AM Joel Stanley <joel@xxxxxxxxx> wrote:
> > +
> > +/ {
> > +       model = "Ampere Mt.Mitchell BMC";
> > +       compatible = "ampere,mtmitchell-bmc", "aspeed,ast2600";
> > +
> > +       chosen {
> > +               stdout-path = &uart5;
>
> I know you've been told by Arnd and others to remove the default
> command line here, but without it your device tree fails to produce
> any output in my tests:
>
> qemu-system-arm -M ast2600-evb -nographic -dtb
> arch/arm/boot/dts/aspeed-bmc-ampere-mtmitchell.dtb -kernel
> arch/arm/boot/zImage
>
> Without a working test, I can't tell the difference between a broken
> device tree and one that omits the serial device on the command line.
> Can you work with Arnd to come to a solution here?

If you use qemu as the boot loader, I think the expected way to do
this is to use the "-append" command line argument along with "-kernel".

Is there any reason for this machine to be special here?

       Arnd