Hi,

The dynamic memory manager has been extensively described in the documentation which will be released with the next RKit-STM8. I copy the interesting part from it below.

Actually you must NOT include alloc.h, but stdlib.h, but you have to call an initialization function mempool_init at the beginning of your program.

Let me know if you still have problems.
Regards,
Bruno

4.15 Using the dynamic memory manager

RCSTM8 includes support for allocating and freeing dynamic memory.
The dynamic memory handling functions are defined in the standard header file as follows:

void *malloc(size_t size); allocates an object of size 'size', and returns the address of the object if successful; otherwise, it returns a null pointer. The values stored in the object are indeterminate.

void *calloc(size_t nelem, size_t size); allocates an array object containing 'nelem' elements each of size 'size', stores zeros in all bytes of the array, and returns the address of the first element of the array if successful; otherwise, it returns a null pointer.

void *realloc(void *ptr, size_t size); allocates an object of size 'size', possibly obtaining initial stored values from the object whose address is 'ptr'. It returns the address of the new object if successful; otherwise, it returns a null pointer.

void free(void *ptr); If 'ptr' is not a null pointer, the function deallocates the object whose address is 'ptr'; otherwise, it does nothing. You can deallocate only objects that have been allocated by calling calloc, malloc, or realloc.

The dynamic memory comes from a "heap" of available space, which must first be granted to the dynamic memory manager. This must be done using the mempool_init function before any call to dynamic memory functions is performed.

void mempool_init(void *ptr, size_t size); initializes the dynamic memory manager and provides a memory buffer of size 'size' at the address pointed to by 'ptr' for the heap.

Note: The dynamic memory manager requires at least 32 bytes to be functional. This is the
minimal size of the buffer to be passed to mempool_init().

4.15.1 Dynamic memory manager example

Here is an example that shows how the dynamic memory manager can be used:

#include 
#include 
#include 

/* Buffer for the dynamic memory manager (32 bytes minimum) */
unsigned char mempool_buffer[100];

char* buffer;

void main( void )
{
    /* Initialization of the dynamic memory manager */
    mempool_init( mempool_buffer, sizeof( mempool_buffer ) );

    /* Allocates a 40-byte buffer */
    buffer = (char *)malloc( 40 );
    if( buffer != NULL )
    {
        /* Write something in the buffer and then print it */
        strcpy( buffer, "hello" );
        printf( "40 chars buffer at address 0x%04x, contains \"%s\"\n", buffer, buffer );
        free( buffer );
    }
    else
    {
        printf( "Allocation error: Returned 0x%04x\n", buffer );
    }

    while(1);
}