Sample Usage

#include "mbed.h"
#include "rtos.h"
#include "Shell.h"

Serial pc(p9,p10);

#define SHELL_STACK_SIZ 1024
// Pre-allocate the shell's stack (on global mem)
unsigned char shellStack[SHELL_STACK_SIZ];
Shell shell(&pc);

// Shell Commands
/**
 *  \brief Gets the amount of free memory
 *  \param none
 *  \return none
 **/
static void cmd_mem(Stream * strm, int argc, char * argv[])
{
   // In order to get free mem within RTOS
   // we need to get the main thread's stack pointer
   // and subtract it with the top of the heap
   // ------+-------------------+   Last Address of RAM (INITIAL_SP)
   //       | Scheduler Stack   |
   //       +-------------------+
   //       | Main Thread Stack |
   //       |         |         |
   //       |         v         |
   //       +-------------------+ <- bottom_of_stack/__get_MSP()
   // RAM   |                   | 
   //       |  Available RAM    |  
   //       |                   |  
   //       +-------------------+ <- top_of_heap
   //       |         ^         |
   //       |         |         |
   //       |       Heap        |
   //       +-------------------+ <- __end__ / HEAP_START (linker defined var)
   //       | ZI                |
   //       +-------------------+
   //       | ZI: Shell Stack   |
   //       +-------------------+
   //       | ZI: Idle Stack    |
   //       +-------------------+
   //       | ZI: Timer Stack   |
   //       +-------------------+
   //       | RW                |  
   // ------+===================+  First Address of RAM
   //       |                   |
   // Flash |                   |
   //

   uint32_t bottom_of_stack = __get_MSP();
   char     * top_of_heap =  (char *) malloc(sizeof(char));
   uint32_t diff = bottom_of_stack - (uint32_t) top_of_heap;

   free((void *) top_of_heap);

   strm->printf("Available Memory : %d bytes\r\n",
        diff);
}

int main() {

    // Start the shell
    pc.printf("Starting debug shell ...\r\n");
    shell.addCommand("mem", cmd_mem);
    shell.start(osPriorityNormal, SHELL_STACK_SIZ, shellStack);

    while(1) {
        wait(0.2);
    }      
}