docs/system/gdb.rst

4 ---------
6 QEMU supports working with gdb via gdb's remote-connection facility
7 (the "gdbstub"). This allows you to debug guest code in the same
8 way that you might with a low-level debug facility like JTAG
13 In order to use gdb, launch QEMU with the ``-s`` and ``-S`` options.
14 The ``-s`` option will make QEMU listen for an incoming connection
15 from gdb on TCP port 1234, and ``-S`` will make QEMU not start the
18 connection, use the ``-gdb dev`` option instead of ``-s``. See
21 .. parsed-literal::
23    |qemu_system| -s -S -kernel bzImage -drive file=rootdisk.img,format=raw -append "root=/dev/sda"
59 As TCG cannot track all memory accesses in user-mode there is no
71 Debugging user-space in system emulation
74 While it is technically possible to debug a user-space program running
78 debug some interaction between kernel and user-space you are better
100 them using gdb's usual thread-management commands.
102 For multi-cluster machines, unfortunately gdb does not by default
104 to them. First, you must connect with the ``extended-remote``
107     (gdb) target extended-remote localhost:1234
113   (gdb) add-inferior
128     1.1  Thread 1.1 (cortex-m33-arm-cpu cpu [running]) 0x00000000 in ?? ()
129   * 2.1  Thread 2.2 (cortex-m33-arm-cpu cpu [halted ]) 0x00000000 in ?? ()
131 You probably also want to set gdb to ``schedule-multiple`` mode,
135   (gdb) set schedule-multiple on
148 .. parsed-literal::
150 …|qemu_system| -chardev socket,path=/tmp/gdb-socket,server=on,wait=off,id=gdb0 -gdb chardev:gdb0 -S…
155    (gdb) target remote /tmp/gdb-socket
163 Changing single-stepping behaviour
185       received: "ENABLE=1,NOIRQ=2,NOTIMER=4"
198    This will change the single step mask, so if wanted to enable IRQs on
235 qemu-user, it allows directly downloading any file readable by QEMU from the