From: Bjorn Helgaas <bjorn.helgaas@hp.com>
To: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Subject: Re: uart_match_port() question
Date: Wed, 7 Dec 2005 16:36:33 -0700
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On Wednesday 07 December 2005 4:13 pm, Benjamin Herrenschmidt wrote:
> ...  Part of the problem here is for example PIO. There is no such
> thing as PIO on a PowerPC, it's purely a PCI abstraction, thus inX/outX
> will only work once the PCI host briges have been discovered and their
> IO space mapped (setup_arch() time, but I definitely want my early
> console earlier).

ia64 has a similar problem, but it's a bit easier because firmware
configures and tells us about the legacy (0-64K) I/O port space.
So we do have to look up the MMIO base where those I/O ports get
mapped, but that's basically the first thing in setup_arch().  We
don't do much before that, so it hasn't been worthwhile to make
the console work earlier.
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