[PATCH 0/2] Early printk support for virtio console devices.

[Peter Maydell]

On 6 May 2013 06:11, Rusty Russell <rusty at rustcorp.com.au> wrote:
> Peter Maydell <peter.maydell at linaro.org> writes:
>> To be actually useful we need to also specify something in
>> the device tree to say "here is where you will find your
>> emergency output and what it is".
>
> Hmm, I'm not sure that's true.  It looks like it needs:
>
> 1) An enhancment to the vdev->set_config callback to pass through (at
>    least) an offset, probably offset and length.
>
> 2) An emerg_write() function ptr which can be called at any time, set by
>    virtio_console.c's class_init:

That all looks like sensible QEMU implementation possibilities
but it seems to be a bit of a non-sequitur from "how do we
tell the kernel to actually use this?"

-- PMM