Re: constraints on rbus_min_start?

["Steven M. Bellovin" <smb%cs.columbia.edu@localhost>]

On Mon, 07 Jan 2008 21:39:53 -0500
Greg Troxel <gdt%ir.bbn.com@localhost> wrote:

> I am confused about the rbus area.  On some machines (Thinkpad 600E),
> rbus_min_start has to be 512 MB, and this seems to have something to
> do with the processor not addressing > 1GB.
> 
> I have been under the impression that the PCI memory space was in
> physical addresses, and that rbus_min_start was in virtual.  But I
> have never really been clear on this.
> 
>   When I tried a compact flash disk, I was told "card appears to have
>   bogus CIS".  It behaves just fine on an i386.
> 
> I think this is different from "bad rbus_min_start".  On my T60,
> cardbus cards work fine with rbus_min_start auto-sized to 2 GB (2 GB
> ram in it), even one of those pesky EVDO cards, vz and sprint.  But
> pcmcia cards lose with a similar message to yours.
> 
I don't think I have any other PCMCIA or Cardbus cards around.  But
I've been using the CF card for years on a T42, without any problems.
As I said, I took the same card+slot adapter and inserted it into the
T42 immediately after the amd64 failure on my T61.  Maybe it's a
different failure...


                --Steve Bellovin, http://www.cs.columbia.edu/~smb