Function rt_smem_init

src/mem.c:170–234

* @brief This function will initialize small memory management algorithm. * * @param name is the name of the small memory management object. * * @param begin_addr the beginning address of memory. * * @param size is the size of the memory. * * @return Return a pointer to the memory object. When the return value is RT_NULL, it means the init failed. */

 * @return Return a pointer to the memory object. When the return value is RT_NULL, it means the init failed.
 */
rt_smem_t rt_smem_init(const char    *name,
                     void          *begin_addr,
                     rt_size_t      size)
{
    struct rt_small_mem_item *mem;
    struct rt_small_mem *small_mem;
    rt_uintptr_t start_addr, begin_align, end_align, mem_size;

    small_mem = (struct rt_small_mem *)RT_ALIGN((rt_uintptr_t)begin_addr, RT_ALIGN_SIZE);
    start_addr = (rt_uintptr_t)small_mem + sizeof(*small_mem);
    begin_align = RT_ALIGN((rt_uintptr_t)start_addr, RT_ALIGN_SIZE);
    end_align   = RT_ALIGN_DOWN((rt_uintptr_t)begin_addr + size, RT_ALIGN_SIZE);

    /* alignment addr */
    if ((end_align > (2 * SIZEOF_STRUCT_MEM)) &&
        ((end_align - 2 * SIZEOF_STRUCT_MEM) >= start_addr))
    {
        /* calculate the aligned memory size */
        mem_size = end_align - begin_align - 2 * SIZEOF_STRUCT_MEM;
    }
    else
    {
        rt_kprintf("mem init, error begin address 0x%x, and end address 0x%x\n",
                   (rt_uintptr_t)begin_addr, (rt_uintptr_t)begin_addr + size);

        return RT_NULL;
    }

    rt_memset(small_mem, 0, sizeof(*small_mem));
    /* initialize small memory object */
    rt_object_init(&(small_mem->parent.parent), RT_Object_Class_Memory, name);
    small_mem->parent.algorithm = "small";
    small_mem->parent.address = begin_align;
    small_mem->parent.total = mem_size;
    small_mem->mem_size_aligned = mem_size;

    /* point to begin address of heap */
    small_mem->heap_ptr = (rt_uint8_t *)begin_align;

    LOG_D("mem init, heap begin address 0x%x, size %d",
            (rt_uintptr_t)small_mem->heap_ptr, small_mem->mem_size_aligned);

    /* initialize the start of the heap */
    mem        = (struct rt_small_mem_item *)small_mem->heap_ptr;
    mem->pool_ptr = MEM_FREED(small_mem);
    mem->next  = small_mem->mem_size_aligned + SIZEOF_STRUCT_MEM;
    mem->prev  = 0;
#ifdef RT_USING_MEMTRACE
    rt_smem_setname(mem, "INIT");
#endif /* RT_USING_MEMTRACE */

    /* initialize the end of the heap */
    small_mem->heap_end        = (struct rt_small_mem_item *)&small_mem->heap_ptr[mem->next];
    small_mem->heap_end->pool_ptr = MEM_USED(small_mem);
    small_mem->heap_end->next  = small_mem->mem_size_aligned + SIZEOF_STRUCT_MEM;
    small_mem->heap_end->prev  = small_mem->mem_size_aligned + SIZEOF_STRUCT_MEM;
#ifdef RT_USING_MEMTRACE
    rt_smem_setname(small_mem->heap_end, "INIT");