Re: [Qemu-arm] Warning when DTB memory nodes are noped

[Jünger , Lukas]

On Thu, 2018-12-13 at 14:49 +0000, Peter Maydell wrote:
> On Thu, 13 Dec 2018 at 14:42, Jünger, Lukas
> <address@hidden> wrote:
> > 
> > Hi all,
> > 
> > If I understand correctly, all memory nodes contained in a DTB
> > passed
> > via the -dtb option are noped in hw/arm/boot.c:556-568.
> > I did not expect this to happen and only figured it out by
> > debugging
> > the kernel.
> > Do you think a warning should be issued if a DTB contains memory
> > regions that are noped?
> 
> No, because generally we expect that to happen: the DTB will
> have a memory node for whatever the stock amount of RAM on the
> target board is, but we want to delete that so we can replace
> it with a memory node saying that the system has however much
> RAM the user asked for on the command line.
> 
> Was the deletion of the memory node actually wrong in your case?
> If so we should look at fixing the wrong behaviour, rather than
> just being noisier about what we're doing...
> 
> thanks
> -- PMM

I see. In my case I wanted to specify the memory using the DTB that I
passed using the -dtb option. I had two memory ranges in the dtb and
they didn't show up in the kernel later on because they were noped by
QEMU. I found it confusing that QEMU makes changes to the DTB that I
passed via -dtb. 

Thanks,
Lukas