[Trivia] Debugging Qemu

Intro

First time I tried debugging Qemu, I had some problems with signals, serials, etc.

Debug

configure

Configure qemu to use debug
./configure --enable-debug --enable-fdt --target-list=arm-softmmu

 

signals

add the following lines to your .gdbinit:
handle SIGUSR1 SIGUSR2 noprint nostop 

Qemu uses those signals for timeout and internal stuff, we don't need to track them

 

serials

Then I had problems with serial lines in gdb, Reading the serial worked well but I couldn't write to it...

My workaround is to call:

socat -d -d pty pty 

You get two pty.
Call screen on the second one to be able to write to the serial port. 

References

[0] http://lnotestoself.blogspot.fr/2014/01/arm-debugging-with-qemu-and-gdb.html