subsys/ipc/openamp sample on QEMU not working when debugging

[MartinSchoenstedt]

Describe the bug
Trying to understand the openamp sample I wanted to debug it via QEMU. However, the sample stops working when adding the -S option

To Reproduce
Steps to reproduce the behavior:

1. go to zephyrproject/zephyr/samples/subsys/ipc/openamp
2. build with west build -p -b mps2_an521 . (adding -t run does not work here)
3. run the sample with qemu-system-arm as build/build.ninja describes in line 882
4. Sample works without problems
5. repeat command but add options -s -S to the qemu-system-arm call for debugging
6. start gdb-server and continue
7. Remote core does not start

Environment:

• OS: Linux 64-bit
• Zephyr version: 2.5.99

[galak]

@MartinSchoenstedt I'm guessing this isn't a bug, but more how qemu works w/multicore.

[MartinSchoenstedt]

yes, that could be the case. I was wondering if the problem has occured to anyone else before or if I am the first trying to debug multicore qemu applications.
Reporting the problem on qemu bugtracker as this is likely to be the root cause. https://bugs.launchpad.net/qemu/+bug/1921092

[galak]

@MartinSchoenstedt

Take a look at:

https://lists.nongnu.org/archive/html/qemu-devel/2020-01/msg07035.html

If I use the gdb commands listed here things seem to work for me.