64 lines
2.3 KiB
ReStructuredText
64 lines
2.3 KiB
ReStructuredText
.. zephyr:code-sample:: llext-modules
|
|
:name: Linkable loadable extensions "module" sample
|
|
:relevant-api: llext
|
|
|
|
Call a function in a loadable extension module,
|
|
either built-in or loaded at runtime.
|
|
|
|
Overview
|
|
********
|
|
|
|
This sample demonstrates the use of the :ref:`llext` subsystem in Zephyr. The
|
|
llext subsystem allows for the loading of relocatable ELF files at runtime;
|
|
their symbols can be accessed and functions called.
|
|
|
|
Specifically, this shows how to call a simple "hello world" function,
|
|
implemented in :zephyr_file:`samples/subsys/llext/modules/src/hello_world_ext.c`.
|
|
This is achieved in two different ways, depending on the value of the Kconfig
|
|
symbol ``CONFIG_HELLO_WORLD_MODE``:
|
|
|
|
- if it is ``y``, the function is directly compiled and called by the Zephyr
|
|
application. The caller code used in this case is in
|
|
:zephyr_file:`samples/subsys/llext/modules/src/main_builtin.c`.
|
|
|
|
- if it is ``m``, the function is compiled as an llext and it is included in
|
|
the application as a binary blob. At runtime, the llext subsystem is used to
|
|
load the extension and call the function. The caller code is in
|
|
:zephyr_file:`samples/subsys/llext/modules/src/main_module.c`.
|
|
|
|
Requirements
|
|
************
|
|
|
|
A board with a supported llext architecture and console. This can also be
|
|
executed in QEMU emulation on the :ref:`qemu_xtensa <qemu_xtensa>` or
|
|
:ref:`qemu_cortex_r5 <qemu_cortex_r5>` virtual boards.
|
|
|
|
Building and running
|
|
********************
|
|
|
|
- The following commands build and run the sample so that the files are linked
|
|
together in the same binary:
|
|
|
|
.. zephyr-app-commands::
|
|
:zephyr-app: samples/subsys/llext/modules
|
|
:board: qemu_xtensa
|
|
:goals: build run
|
|
:west-args: -T sample.llext.modules.builtin_build
|
|
:compact:
|
|
|
|
- The following commands build and run the sample so that the extension code is
|
|
compiled separately and included in the Zephyr image as a binary blob:
|
|
|
|
.. zephyr-app-commands::
|
|
:zephyr-app: samples/subsys/llext/modules
|
|
:board: qemu_xtensa
|
|
:goals: build run
|
|
:west-args: -T sample.llext.modules.module_build
|
|
:compact:
|
|
|
|
Take a look at :zephyr_file:`samples/subsys/llext/modules/sample.yaml` for the
|
|
additional architecture-specific configurations required in this case.
|
|
|
|
To build for a different board, replace ``qemu_xtensa`` in the commands above
|
|
with the desired board name.
|