Hello,

From: "Perry E. Metzger" <perry@piermont.com>
Subject: watch out -- more than 1G RAM on a laptop causes cardbus issues
Date: Thu, 26 Feb 2004 21:02:12 -0500
Message-ID: <871xohnuu3.fsf@snark.piermont.com>

 > It turns out that our cardbus code tries to allocate space at the 1GB
 > mark by default when it starts up. As a result of this, if you have
 > more than 1GB of RAM in your laptop, you will lose badly if you boot a
 > GENERIC kernel.
 > 
 > The work around, for the moment, is setting RBUS_MIN_START to
 > something larger than 1G (say, 0x70000000) in your kernel config.

This is because some machines used just above 1G for frame
buffer mapping, if my memory is correct.

 > The code that manipulates all this is sys/arch/i386/i386/rbus_machdep.c
 > 
 > We really need some sort of more permanent solution to this problem,
 > or people may find themselves in a bit of pain when trying to install.

I think so.  Not only memory space, but also i/o space shoud
be managed properly.

 > ACPI can be used on some machines, but some other mechanism needs to
 > be found for machines not running ACPI.

Unfortunately, I can't have enough time to hack kernel.  I
know cardbus (and IEEE 1394 isochronous) should be
overhauled.  But, right now, very limited time I have for
the problem.

If you (or other) can do it, please do it.
-- 
KH