GDB Plug-In

Debugging LVGL with GDB

To facilitate debugging LVGL with GDB, a GDB plugin is provided. This plugin can be found in the lvgl/scripts/gdb directory. The GDB plugin can be used with any target where GDB is available. For example, you can use it to debug a device connected to a PC via JLink, which provides a GDB server. Additionally, if your device crashes and you have a core dump, you can use GDB to analyze the core dump. To load the LVGL GDB plugin within GDB's command line, type the following command:

source lvgl/scripts/gdb/gdbinit.py

Example of usage:

(gdb) source lvgl/scripts/gdb/gdbinit.py

(gdb) dump obj -L 2
obj@0x60700000dd10 (0,0,799,599)
tabview@0x608000204ca0 (0,0,799,599)
    obj@0x607000025da0 (0,0,799,69)
    obj@0x607000025e80 (0,70,799,599)
    obj@0x60700002bd70 (743,543,791,591)
    btn@0x60700002c7f0 (747,547,787,587)
keyboard@0x60d0000f7040 (0,300,799,599)
dropdown-list@0x608000205420 (0,0,129,129)
    label@0x60d0000f7ba0 (22,22,56,39)
(gdb)

The plugin provides the following commands.

• dump obj: Dump the object tree.

• info style: Show the object's style.

Dump obj tree

dump obj: Dump the object tree.

dump obj -L 2: Dump the object tree with a depth of 2.

dump obj -a 0x60700000dd10: Dump the object tree starting from the specified address.

Show obj's style

This command can dump the object's local style, since style value is a union, it's displayed in all possible formats.

info style address_of_obj: Show the object's style.

Example:

(gdb) info style 0x60700000dd10
  32 = {num = 90, ptr = 0x5a, color = {blue = 90 'Z', green = 0 '\000', red = 0 '\000'}}
  158 = {num = 32767, ptr = 0x7fff, color = {blue = 255 '\377', green = 127 '\177', red = 0 '\000'}}
(gdb) p lv_global->disp_default->act_scr
$4 = (lv_obj_t *) 0x60700000dd10
(gdb) info style $4
  32 = {num = 90, ptr = 0x5a, color = {blue = 90 'Z', green = 0 '\000', red = 0 '\000'}}
  158 = {num = 32767, ptr = 0x7fff, color = {blue = 255 '\377', green = 127 '\177', red = 0 '\000'}}
(gdb)

Connect to Debugger

This command provides the ability to connect and debug GDB Python Script using IDE.

Connect to PyCharm / VSCode / Eclipse(not support yet)

debugger -t pycharm

debugger -t vscode

debugger -t eclipse

How to use it specifically, search pydevd_pycharm / debugpy for details.