On 9/16/24 02:21, Stafford Horne wrote:
On Wed, Sep 11, 2024 at 12:42:58AM -0500, Rob Landley wrote:
Grab this tarball, extract it, and ./run-qemu.sh. It's a simple
linux+initramfs image that boots to a shell prompt.
https://landley.net/bin/mkroot/latest/or1k.tgz
QEMU 7.0.0 ran that linux-or1k image, but newer qemu does not. I besected the
issue to qemu commit 0a923be2f642, and it's still broken in current tip of tree.
Patch is:
0a923be2f6 ("hw/openrisc: page-align FDT address")
Rebuilding the image with current linux-git doesn't seem to make a difference?
Either way I get serial output with old qemu and don't with current qemu.
The bisect looks strange as it's only moving a page boundary, it could be
correct but it seems harmeless. There is another commit close by that was
causing issues with serial output for the barebox guys and this is a patch I am
working on to fix it.
https://lore.kernel.org/qemu-devel/20240908062756.70514-1-sho...@gmail.com/
I will try to get time today to look at your tarball and run it, but if not have
a look at this patch.
I just regression tested linux-6.12 against qemu-9.2.0-rc1 and I'm still
getting no output from or1k, with the current image or the old or1k
release image that worked under old qemu versions.
I tried applying your serial patch to current qemu, and it made no
difference: still no output booting the image.
Alas I can no longer test that reverting the commit I identified (git
show $HASH | patch -p1 -r) makes it work again in current qemu (although
it did at one point, that's a standard sanity check at the end of bisect
for me), and I can't fix it up by hand either because
hw/openrisc/openrisc_sim.c no longer contains the string "load_sim",
looks like it got collated with common code for other architectures.
I'm happy to tweak the kernel config if qemu changed in a way that broke
compatibility with old images (I assume _you_ have a kernel that boots),
but I was hoping "this week's kernel release" would have any necessary
patches to work with QEMU's changed ABI.
Thanks,
Rob
