10 请问 platform_mem_desc[ ] 这个数组有什么作用啊？

struct mem_desc platform_mem_desc[] = {
    {0x00000000, 0x80000000, 0x00000000, DEVICE_MEM},
    {0x80000000, 0xFFF00000, 0x80000000, NORMAL_MEM}
};
const rt_uint32_t platform_mem_desc_size = sizeof(platform_mem_desc)/sizeof(platform_mem_desc[0]);