Re: [Qemu-devel] Support for new target emulator

[Alexander Graf]

On 23.10.2009, at 12:50, Boyapati, Anitha wrote:

> Hello,
>
> We have a proposal to add support for AVR32 target emulation in  
> Qemu. So far, we are able to build qemu from sources on windows  
> using Mingw.

I would suggest you try and do this on Linux first. You'll see why  
below.

> Besides looking at sources for other targets in qemu tar ball, I  
> have gone through docs for information on how to start adding  
> support for a new target. I will appreciate if someone can give  
> additional pointers on this. Also, kindly let me know the rough  
> estimate of adding basic support to a new target like AVR32.

Luckily Uli just added support for s390x, so you can take a look at  
his patchset and see what needs to be done.

> There are some threads in Qemu user forums regarding the same.  
> However, link for Qemu user forums is currently reporting a lost  
> connection to mysql server (for the past 4 days?). I did a basic  
> search on Qemu developer mailing list archives and I could not find  
> a relevant thread yet.

I don't know about the user forum, but you should really take a look  
at his patchset.

The reason you should try to do things on Linux is that it's a lot  
easier to implement a user-mode target than a system emulation target.  
So if I were you, I'd start off by implementing an AVR32 Linux  
userspace target. Apart from the syscall translation that should be  
almost completely a subset of the system emulation.

Once you have found your user mode emulation to work, you can start  
implementing the softmmu and privileged opcodes. Also, you'll need  
some sort of "machine" you're running on then. So if I were you again,  
I'd implement a typical AVR32 developer board emulation.

It's great to see someone from Atmel actually taking on the challenge!  
I'd love to see AVR32 support in Qemu. It's FWIW the only completely  
missing major target.

Alex