ota_downloader软件包http_ota下载出现`FPU active!` 和 `SCB_CFSR_BFSR:0x04 IMPRECISERR`

发布于 2024-01-21 17:06:55 浏览：560 订阅该版

[tocm]

## 当前配置
- 软件包安装

![002.png](https://oss-club.rt-thread.org/uploads/20240121/9647a000b062a6433ba96daa228e08f2.png)

- 关键函数调用(main.c)

> 创建8K线程并提高优先级，执行OTA升级指令

```c
void ota(void* p){ http_ota_fw_download("http://192.168.31.233:9000/rtthread.bin");
}
int main() {
	//...
    rt_thread_t  ota_ptr = rt_thread_create("OTA",ota,NULL,1024*8,2,20);
    if(ota_ptr != RT_NULL){
        rt_kprintf("ota_start\n");
        rt_thread_startup(ota_ptr);
    }else{
        rt_kprintf("ota_error\n");
    }
	//...
  return 0;
}
```

- 串口报错

```txt
ota_start
OTA file size is (300032)Start erase flash (download) partition!psr: 0x01000000
r00: 0x00000000
r01: 0xe000ed00
r02: 0x40000000
r03: 0x00000da0
r04: 0xdeadbeef
r05: 0xdeadbeef
r06: 0xdeadbeef
r07: 0x2400fa98
r08: 0xdeadbeef
r09: 0xdeadbeef
r10: 0xdeadbeef
r11: 0xdeadbeef
r12: 0xffffffff
 lr: 0x0804aa87
 pc: 0x0804a7b6
hard fault on thread: OTA

pri  status      sp     stack size max used left tick  error
-------- ---  ------- ---------- ----------  ------  ---------- ---
OTA        2  running 0x00000288 0x00002000    12%   0x0000000e 000
md_send_  31  suspend 0x000000ac 0x00002800    01%   0x0000000a 000
md_poll_  10  suspend 0x000000b0 0x00000200    34%   0x0000000a 000
master t  10  suspend 0x000000b8 0x00000200    35%   0x00000005 000
mqtt0     10  suspend 0x00000240 0x00001000    27%   0x00000001 000
at_clnt    9  ready   0x0000018c 0x00000600    75%   0x00000001 000
tshell    20  suspend 0x00000154 0x00001000    14%   0x0000000a 000
sys work  23  suspend 0x00000260 0x00000800    61%   0x00000001 000
tidle0    31  ready   0x0000006c 0x00000100    61%   0x0000000a 000
timer      4  suspend 0x00000080 0x00000200    34%   0x00000009 000
FPU active!
```

* 查阅`Debug`->`rtthread.map`文件中，在`PC: 0x08040a7b6`附近的文件内容如下:**问题文件位于`drv_flash_h7.c`，关于该文件详见本文备注**

```txt
 .text.esp8266_connect
                0x0804a53c       0xd0 ./applications/src/WIFI.o
                0x0804a53c                esp8266_connect
 .text.freeModbus_Init
                0x0804a60c       0xb0 ./applications/src/freeModbus.o
                0x0804a60c                freeModbus_Init
 .text.md_poll_thread
                0x0804a6bc       0x18 ./applications/src/freeModbus.o
                0x0804a6bc                md_poll_thread
 .text.md_send_and_receice_thread
                0x0804a6d4       0x14 ./applications/src/freeModbus.o
                0x0804a6d4                md_send_and_receice_thread
 .text.SCB_EnableDCache
                0x0804a6e8       0x80 ./applications/drv_flash_h7.o
 .text.SCB_DisableDCache
                0x0804a768       0x80 ./applications/drv_flash_h7.o
 .text.stm32_flash_read
                0x0804a7e8       0x78 ./applications/drv_flash_h7.o
                0x0804a7e8                stm32_flash_read
 .text.stm32_flash_write
                0x0804a860      0x178 ./applications/drv_flash_h7.o
                0x0804a860                stm32_flash_write
```

* `0x0804a7b6`介于`0x0804a768`和`0x0804a7e8`之间，所以自认为问题应该出现在

```txt
 .text.SCB_DisableDCache
                0x0804a768       0x80 ./applications/drv_flash_h7.o
```

* `SCB_DisableDCache`函数位于`core_cm7.h`中,函数内容如下:

```c
/**
  \brief   Disable D-Cache
  \details Turns off D-Cache
  */
__STATIC_INLINE void SCB_DisableDCache (void)
{
  #if defined (__DCACHE_PRESENT) && (__DCACHE_PRESENT == 1U)
    uint32_t ccsidr;
    uint32_t sets;
    uint32_t ways;

SCB->CSSELR = 0U; /*(0U << 1U) | 0U;*/  /* Level 1 data cache */
    __DSB();

SCB->CCR &= ~(uint32_t)SCB_CCR_DC_Msk;  /* disable D-Cache */
    __DSB();

ccsidr = SCB->CCSIDR;

/* clean & invalidate D-Cache */
    sets = (uint32_t)(CCSIDR_SETS(ccsidr));
    do {
      ways = (uint32_t)(CCSIDR_WAYS(ccsidr));
      do {
        SCB->DCCISW = (((sets << SCB_DCCISW_SET_Pos) & SCB_DCCISW_SET_Msk) |
                       ((ways << SCB_DCCISW_WAY_Pos) & SCB_DCCISW_WAY_Msk)  );
        #if defined ( __CC_ARM )
          __schedule_barrier();
        #endif
      } while (ways-- != 0U);
    } while(sets-- != 0U);

__DSB();
    __ISB();
  #endif
}
```

### 解决过程

> 查阅过一些`FPU active!`的问题，好像是结构体浮点数对齐的问题，由于才疏学浅还找不到具体问题以及解决办法。

### 备注

* `drv_flash_h7.c`文件是`rt-threrad`->`fal`组件对于h7系列芯片的分区时的一些配置代码,源文件位于`https://gitee.com/rtthread/rt-thread/blob/master/bsp/stm32/libraries/HAL_Drivers/drivers/drv_flash/drv_flash_h7.c`。

```c
const struct fal_flash_dev stm32_onchip_flash_128k = {
    "onchip_flash_128k",
    0x08020000,
    (2*1024-128) * 1024,
    (128 * 1024),
    {NULL, fal_flash_read_128k, fal_flash_write_128k, fal_flash_erase_128k},
    8};
```