使用memheap方式添加第二块内存，获取到的地址一直是同一个。

#define STM32_FLASH_START_ADRESS     ((uint32_t)0x08000000)
#define STM32_FLASH_SIZE             (2048 * 1024)
#define STM32_FLASH_END_ADDRESS      ((uint32_t)(STM32_FLASH_START_ADRESS + STM32_FLASH_SIZE))
#define STM32_SRAM_SIZE           (512)
#define STM32_SRAM_END            (0x24000000 + STM32_SRAM_SIZE * 1024)
#define STM32_SRAM2_START_ADRESS     (0x30000000)
#define STM32_SRAM2_SIZE          (288 * 1024)
#define STM32_SRAM2_END           (STM32_SRAM2_START_ADRESS + STM32_SRAM2_SIZE)
#if defined(__ARMCC_VERSION)
extern int Image$$RW_IRAM1$$ZI$$Limit;
#define HEAP_BEGIN      (&Image$$RW_IRAM1$$ZI$$Limit)
#elif __ICCARM__
#pragma section="CSTACK"
#define HEAP_BEGIN      (__segment_end("CSTACK"))
#else
extern int __bss_end;
#define HEAP_BEGIN      (&__bss_end)
#endif
#define HEAP_END        STM32_SRAM_END