From: Hollis Blanchard <hollisb@us.ibm.com>
To: Rob Landley <rob@landley.net>
Cc: firmware@them.com, qemu-devel <qemu-devel@nongnu.org>
Subject: [Qemu-devel] endianness and network emulation for PowerPC
Date: Mon, 18 Feb 2008 14:57:57 -0600 [thread overview]
Message-ID: <1203368277.3428.62.camel@basalt> (raw)
I've been debugging network problems in qemu for a week or two, and
there seem to be some pervasive misunderstandings about endianness. I'm
trying to use a big-endian target on a big-endian guest, and this has
exposed a lot of breakage, including qemu's pci-host.h, isa_mmio.c,
rtl8139.c and ne2000.c.
Rob, I noticed that you're using Linux's "ne.c" in your PowerPC PReP
kernel build for qemu, and to my surprise it actually works for me on a
big-endian host! I'm wondering if you chose ne.c because you found the
other network drivers to be broken?
(Actually I believe this is also working by accident: outsw() in Linux
writes big-endian data, which is incorrectly swapped in isa_mmio.c, and
then incorrectly swapped again in ne2000.c.)
--
Hollis Blanchard
IBM Linux Technology Center
next reply other threads:[~2008-02-18 20:59 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2008-02-18 20:57 Hollis Blanchard [this message]
2008-02-19 18:05 ` [Qemu-devel] Re: endianness and network emulation for PowerPC Rob Landley
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