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Re: [Xen-devel] [PATCH] Console Daemon

On 3 Aug 2005, at 11:58, Rusty Russell wrote:

        I have some old code I wrote for the IBM Research Hypervisor which
implements a console.  I stole that ring buffer code for the xenstore,
in fact.

        I don't think externally-supplied pages are necessary.  I was thinking
of writing the page (or pages) into the store immediately (since we
don't need locks, or to wait for a reply).  I think we want more than
one page because my boot messages almost hit 8k to the first login
prompt, and the idea of requiring a console daemon repulses me.

We want an initial console page initialised outside xenbus because we want to get console *early*. We don;t trust xenbus/xenstore enough just yet to enable them in the wild with no console diagnostics available. :-)

We'll add support for multiple consoles and multi-page console buffers via the xenbus later on. This is just supposed to be a really simple ring buffer of raw console bytes, with the ring page initialised same way as the xenstore page.

This only differs from what Robert may be thinking about already in that I don;t think we care about muxing multiple consoles onto a single ring. We'd just set up multiple ring buffers via xenbus. But that is definitely 'phase 2'!

 -- Keir

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