Re: how to add a new machine?

[Peter Maydell]

On Fri, 19 Feb 2021 at 08:13, <ckim@etri.re.kr> wrote:
> If I have to make a qemu machine for our future real system, can't I really 
> just use virt (or copied version of virt for modification) and add our 
> peripheral model? The purpose is to provide environment for software 
> developers (using our peripheral which will take some time until functioning 
> stage) and it doesn't need to be cycle accurate(of course qemu isn't for 
> that), or even the processor doesn't need to be the same one for our 
> development. I think we can just use cortex-a72 model for some time and 
> change the model for more accurate emulation. Is it a possibility? Or as you 
> said I have to choose an emulator model for a real system?

Well, you can do whatever you like, if you're making
a purely local hack for your own purposes. My answers
are more framed in the direction of "what would I do"
and "what would you need to do if you were interested
in possibly getting this code upstream".

> Also I'm curious if for other machines, the DTB(device tree blob) is 
> automatically generated like in 'virt' machine.

No, the 'virt' machine is special in this regard. For
other machines, QEMU has a more straightforward approach
of "we just emulate the hardware", and in the same way
that on real hardware it's the user's job to supply
the dtb together with the kernel, the user has to pass
QEMU a -dtb option if their kernel needs a dtb.

-- PMM