docs/system/gdb.rst

4 ---------
6 QEMU supports working with gdb via gdb's remote-connection facility
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 -hda rootdisk.img -append "root=/dev/hda"
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
76 and execution mode changes between kernel and user mode can make it
78 debug some interaction between kernel and user-space you are better
88 machine has more than one CPU, QEMU exposes each CPU cluster as a
89 separate "inferior", where each CPU within the cluster is a separate
91 single cluster which has all the CPUs in it.  A few machine types are
93 machine has a cluster with one E51 core and a second cluster with four
99 cluster using the gdb ``info thread`` command, and switch between
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
110 first cluster. You need to create inferiors for the other
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,
133 not just those in the cluster you are currently working on::
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
217 The memory mode can be checked by sending the following command:
221     physical memory mode.
224     This will change the memory mode to physical memory.
227     This will change it back to normal memory mode.
235 qemu-user, it allows directly downloading any file readable by QEMU from the