Electronic – Understanding RS Component’s “Program Memory Size”

Here is the simplest possible LED flasher program that works on the STM32VL Discovery board:

/* Test.c
** Simple program for STM32F100RB to flash LED on PC_9
**
*/

#include <stm32f10x.h>

void delay(void);

void main(void)
{
  // I/O port C clock enable
  RCC->APB2ENR = RCC_APB2ENR_IOPCEN;
  // Set PC_9 to output 
  GPIOC->CRH &= ~(GPIO_CRH_MODE9 | GPIO_CRH_CNF9);
  GPIOC->CRH |= GPIO_CRH_MODE9;

  while(1)
  {
    GPIOC->BSRR = (1<<9);
    delay();
    GPIOC->BRR = (1<<9);
    delay();
  }
}

void delay(void)
{
  volatile unsigned int i;

  for (i = 0; i < 20000; i++)
    ;
}

Basically your task will be to program a bootloader onto the one at the very end. That bootloader will need to accept specific commands via UART which causes it to reboot (watchdog?) and then enter the bootloader section. From the bootloader, it will again accept data which will overwrite your application area. After the update is done, boot to your application section (until you receive the command to update again).

Are you planning for a redesign at this point?