zephyr

History

Keith Packard 0b90fd5adf samples, tests, boards: Switch main return type from void to int As both C and C++ standards require applications running under an OS to return 'int', adapt that for Zephyr to align with those standard. This also eliminates errors when building with clang when not using -ffreestanding, and reduces the need for compiler flags to silence warnings for both clang and gcc. Most of these changes were automated using coccinelle with the following script: @@ @@ - void + int main(...) { ... - return; + return 0; ... } Approximately 40 files had to be edited by hand as coccinelle was unable to fix them. Signed-off-by: Keith Packard <keithp@keithp.com>		2023-04-14 07:49:41 +09:00
..
boards	init: remove the need for a dummy device pointer in SYS_INIT functions	2023-04-12 14:28:07 +00:00
src	samples, tests, boards: Switch main return type from void to int	2023-04-14 07:49:41 +09:00
CMakeLists.txt	treewide: update usage of zephyr_code_relocate	2023-01-17 18:08:37 +01:00
linker_arm_nocopy.ld	linker: update files with <zephyr/...> include prefix	2022-05-09 12:45:29 -04:00
prj.conf	samples: code_relocation_nocopy: Disable gap filling	2022-06-24 20:29:00 +02:00
README.rst	samples: code_relocation_nocopy: Update documentation	2022-06-24 20:29:00 +02:00
sample.yaml	yamllint: indentation: fix files in samples/	2023-01-04 14:23:53 +01:00

README.rst

.. _code_relocation_nocopy:

Code relocation nocopy
######################

Overview
********
A simple example that demonstrates how relocation of code, data or bss sections
using a custom linker script.

Differently from the code relocation sample, this sample is relocating the
content of the ext_code.c file to a different FLASH section and the code is XIP
directly from there without the need to copy / relocate the code.

nRF5340 DK platform instructions
********************************

The nRF5340 DK has a 64 Mb external flash memory supporting Quad SPI. It is
possible to do XIP from the external flash memory.

The external flash memory is mapped to 0x10000000.

In this sample we relocate some of the code to the external flash memory with
the remaining Zephyr kernel in the internal flash.

To build and flash the application (including the external memory part):

.. zephyr-app-commands::
   :zephyr-app: samples/application_development/code_relocation_nocopy
   :board: nrf5340dk_nrf5340_cpuapp
   :goals: build flash
   :compact:

Execution output:

.. code-block:: console

  *** Booting Zephyr OS build v3.0.0-rc3-25-g0df32cec1ff2  ***
  Address of main function 0x4f9
  Address of function_in_ext_flash 0x10000001
  Address of var_ext_sram_data 0x200000a0 (10)
  Address of function_in_sram 0x20000001
  Address of var_sram_data 0x200000a4 (10)
  Hello World! nrf5340dk_nrf5340_cpuapp