RT1052 rtthread 报错"FPU active!" "UNALIGNED"

发布于 2020-03-27 10:44:27 浏览：2638 订阅该版

* 本帖最后由 parkin 于 2020-3-27 10:49 编辑 *

问题:
    RT1052 rtthread 报错"FPU active!" "UNALIGNED"

开发环境:
    RT-Thread: v4.0.2(master)
    SOC: i.MX RT1050
    Board: 野火 RT1052
问题背景:
    我创建了一个线程去解析UDP数据, 而数据形式是我定义好的一个结构体的形式, 我使用结构体指针去取对应的值, 取前面的值都可以, 但取到float类型的成员时, 程序崩溃, 报如下错误:
[align=center]![1.png](/uploads/202003/27/103745ole83fyvgevwy3eg.png)使用到的结构体:```typedef struct
{
    unsigned char protocol_flag;
    unsigned char protocol_version;
    unsigned char direction;
    unsigned char cmd;
    unsigned int len;
} UdpProtocolHead;

typedef struct
{
 UdpProtocolHead head;
 unsigned int data1;
 unsigned int data2;
 unsigned int data3;
 unsigned int data4;
 float data5;
 float data6;
} UdpProtocolData;```
[align=center]
问题代码:
```int8_t handle_data_tophalf(uint8_t* data, uint32_t len, struct sockaddr_in* client_addr){
 UdpProtocolData* data = (UdpProtocolData*)data;
 
 uint8_t* p = (uint8_t*)&data->data5;
 printf("data5: %x %x %x %x ", p[0], p[1], p[2], p[3]);
 printf("data5: %f ", data->data5);
 p = (uint8_t*)&data->fy; 
 printf("data6: %x %x %x %x ", p[0], p[1], p[2], p[3]);
 printf("data6: %f ", data->data6);
}```

问题自测:
 我在main中编写了自测代码来模拟现场, 运行正常, 代码如下:char data2[] = {0xff, 0x01, 0x00, 0x10, 0x20, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 , 0x00, 0x00, 0x00, 0x20, 0x10, 0x20, 0x2d, 0x00, 0x00, 0x00, 0x40, 0x00, 0x00, 0x80, 0x3f};uint8_t* p2 = rt_malloc(sizeof(data2));memcpy(p2, data2, sizeof(data2));UdpProtocolData* pdata = (UdpProtocolData*)p2;printf("head: %x %x %x %x %d ", pdata->head.protocol_flag, pdata->head.protocol_version , pdata->head.direction, pdata->head.cmd, pdata->head.len);printf("head: %x %x %x %x ", pdata->data_type, pdata->data_index, pdata->timestamp_s, pdata->timestamp_ns);printf("data: %f %f ", pdata->fy, pdata->fx);
(提供一个网站错误: 以上代码无法插入为代码格式)运行结果如下:
```head: ff 1 0 10 32
head: 0 0 0 2d201020
data: 2.000000 1.000000```