Re: [Qemu-devel] [PATCH] Implement PC port80 debug register.

[Jordan Justen]

Anthony,

That seems like a reasonable request.

So, a 'info port80' command would be preferable to having i/o port 0x80 be read/write?

I still think the read/write port route would
* better emulate systems,
* be more flexible (allowing software the option to read it),
* and, be easier to implement :)

But, I think the most important part is to make the data accessible somehow.  So, the monitor access method would work fine as well.

-Jordan

On Mon, Jun 29, 2009 at 8:31 AM, Anthony Liguori <address@hidden> wrote:

Jordan Justen wrote:

Avi,

Well, I am not sure if this it globally the case for PC motherboards, but in my experience, it has been read/write.

At least for a system such as qemu, it make it difficult to use the port80 checkpoint of software without being able to read the last value written.

It seems like the more logical thing to do is to save the port80 write and have it obtainable via the monitor.

But really, we have other debug mechanisms for BIOSes (like ports 50x/40x).  That seems like a better thing to use if you're writing custom code for QEMU.

Regards,

Anthony Liguori