I'm having issues with a project based on an STM32WB5MM where some devices fail to operate BLE (like advertising, for example). The project integrates SBSFU and BLE_ota.
I'm reviewing the linker files and I see differences in the management of the BLE buffer between a standalone application and an application with OTA and SBSFU.
In the standalone application generated by STM32CubeIDE, I have this in the linker file:
.ARM.attributes 0 : { *(.ARM.attributes) }
MAPPING_TABLE (NOLOAD) : { *(MAPPING_TABLE) } >RAM_SHARED
MB_MEM1 (NOLOAD) : { *(MB_MEM1) } >RAM_SHARED
/* used by the startup to initialize .MB_MEM2 data */
_siMB_MEM2 = LOADADDR(.MB_MEM2);
.MB_MEM2 :
{
_sMB_MEM2 = . ;
*(MB_MEM2) ;
_eMB_MEM2 = . ;
} >RAM_SHARED AT> FLASH
and in the application with integrated SBSFU and OTA, I have:
.ARM.attributes 0 : { *(.ARM.attributes) }
MAPPING_TABLE (NOLOAD) : { *(MAPPING_TABLE) } >RAM_SHARED
MB_MEM1 (NOLOAD) : { *(MB_MEM1) } >RAM_SHARED
MB_MEM2 (NOLOAD) : { _sMB_MEM2 = . ; *(MB_MEM2) ; _eMB_MEM2 = . ; } >RAM_SHARED
where the symbol _siMB_MEM2 does not appear, and the buffer contents are not preloaded from flash. This linker is taken from the SBSFU package and matches the BLE_HeartRate_ota example.
I can also see that, in the standalone application, the symbol _siMB_MEM2 is used to initialize that memory section during startup. This initialization is not present in the SBSFU/OTA example nor in BLE_HeartRate_ota.
In startup_stm32wb5mmghx.s:
/* Copy the data segment initializers from flash to SRAM */
INIT_DATA _sdata, _edata, _sidata
INIT_DATA _sMB_MEM2, _eMB_MEM2, _siMB_MEM2
Since in the SBSFU/OTA version the microcontroller can switch between applications, should I assume that the buffer initialization is not needed? Or should I always reinitialize that buffer, and thus avoid using the example linker files? I'm a bit confused by the BLE instability.
Thanks in advance.
