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. All other code (e.g. main(), Zephyr kernel) stays in the internal flash.

nRF5340 DK platform instructions

The nRF5340 DK has a 64 Mb external flash memory supporting Quad SPI. It is mapped to 0x10000000.

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

west build -b nrf5340dk/nrf5340/cpuapp samples/application_development/code_relocation_nocopy
west flash

STM32F769I-Discovery platform instructions

The stm32f769i_disco has 64MB of external flash attached via QSPI. It is mapped to 0x90000000.

west build -b stm32f769i_disco samples/application_development/code_relocation_nocopy
west flash

STM32 b_u585i_iot02a Discovery kit instructions

The b_u585i_iot02a has 64MB of external flash attached via OSPI. It is mapped to 0x70000000.

west build -b b_u585i_iot02a samples/application_development/code_relocation_nocopy
west flash

Execution output

*** 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