I also have a separate but related question around the internal flash programming. Is the only way to program/erase the internal flash, from the user application code or the IAR flash writer’s monitor code, by calling the IAP (boot rom) flash programming APIs? If so, can you please clarify on the amount of SRAM0 these boot ROM/IAP can use? 220.127.116.11 is troubling. If the internal boot rom/IAP calls require access to the SRAM0 (or other memory/shared resources) then Microsoft needs to have a list of all such usages, for their secondary boot loader. If their application needs to call the IAP APIs then they would need to budget resources accordingly. Thank you.