Re: Microblaze image hanging in qemu with 3.15-rc
From: Guenter Roeck
Date: Thu Apr 24 2014 - 09:38:48 EST
On 04/23/2014 11:16 PM, Michal Simek wrote:
On 04/23/2014 05:45 PM, Guenter Roeck wrote:
On Wed, Apr 23, 2014 at 04:12:59PM +0200, Michal Simek wrote:
On 04/23/2014 03:38 PM, Guenter Roeck wrote:
On 04/22/2014 10:32 PM, Michal Simek wrote:
Hi Guenter,
On 04/22/2014 07:23 PM, Guenter Roeck wrote:
Hi all,
when trying to run a microblaze image with 3.15-rc1 or 3.15-rc2 in qemu,
I get the following hangup. This used to work with earlier kernels
with the same configuration.
Is this a known problem, or is something wrong with my configuration
or with my qemu command line ?
Is this BE/LE version? Which qemu do you use?
BE.
file vmlinux:
vmlinux: ELF 32-bit MSB executable, version 1 (SYSV), statically linked, BuildID[sha1]=5e1872c08df2956eddaed6fc1f6528a8540375b7, not stripped
qemu-system-microblaze --version:
QEMU emulator version 1.7.0, Copyright (c) 2003-2008 Fabrice Bellard
gcc --version:
microblaze-linux-gcc (GCC) 4.8.0
Copyright (C) 2013 Free Software Foundation, Inc.
This is free software; see the source for copying conditions. There is NO
warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
There is endian autodetection in timer and intc driver
which can caused this problem.
Is this new code ? I didn't see the problem in 3.13 (same compile options,
same configuration, same compiler, same qemu version).
yes it was added to 3.15-rc1.
Try to rever this one
a66a626 microblaze: Use asm-generic/io.h
but the problem is probably here because you are not getting proper
reaction from qemu model.
a1715bb microblaze: Make timer driver endian aware
1aa1243 microblaze: Make intc driver endian aware
I have tested it on the latest petalinux qemu and there shouldn't be
any problem.
Hi Michal,
qemu 2.0.0 still has the problem. Bisect points to
commit a66a626538af65cbfc611e2b2fce500ed3f24518
Author: Michal Simek <michal.simek@xxxxxxxxxx>
Date: Thu Feb 7 15:12:24 2013 +0100
microblaze: Use asm-generic/io.h
as the culprit, so you were right on the money. Reverting this commit
fixes the problem.
yep. But it is just side effect of previous two commits I have mentioned.
Can you just please check if you are setting up correct IO functions?
write_fn = timer_write32;
read_fn = timer_read32;
write_fn(TCSR_MDT, timer_baseaddr + TCSR0);
if (!(read_fn(timer_baseaddr + TCSR0) & TCSR_MDT)) {
write_fn = timer_write32_be;
read_fn = timer_read32_be;
}
git
The read returns 0x1, so the access functions are not updated. If I change the code
to force the update to the _be versions, the calibration loop still hangs (obviously,
because then the result is 0x01000000, which is really wrong).
Assuming this is in fact a problem with qemu, can you point me to a set
of qemu patches necessary to fix it ? Also, do you know if there are plans
to send the patches upstream ? I don't find anything related in the qemu
repository (though of course I may have missed it).
Yes, it should be qemu issue. I am not aware about particular qemu patches
but you can try to use https://github.com/Xilinx/qemu
but now sure if Peter updating this repository.
Last commit in that repository is from a year ago, so it looks like he doesn't
update it.
Anyway if you look at code above and I expect that the problem is just
that autodetection is broken in your qemu it should be pretty simple
to fix it.
Not sure I understand what you'd expect qemu to return in this case,
and why it worked previously. Any idea ?
Thanks,
Guenter
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