(STM32F4) IAP程式碼實現

IAP學習, 主要想了解實際上程式碼放在不同的Flash位置如何轉跳且執行。

我的應用程序只做了Pin12, Pin13 LED閃爍來分辨我的 App1 跟 App2的程式碼

App1 程式碼

 1 int main(void)
 2 {
 3     Delay_Init();
 4     LED_Config();
 5     EXIT_GPIO_Config();
 6     printf("\n--------------------------------------------------\n");
 7     printf("\n                 STM32F4 IAP APP1                 \n");
 8     printf("\n--------------------------------------------------\n");
 9     
10         /* Flash unlock */
11     FLASH_If_FlashUnlock();
12 
13     /* Test if User button on the Discovery kit is pressed */
14     if (GPIO_ReadInputDataBit(GPIOA, GPIO_Pin_0) == Bit_RESET)
15     {
16         /* Check Vector Table: Test if user code is programmed starting from address 
17            "APPLICATION_ADDRESS" */
18         if (((*(__IO uint32_t*)APPLICATION_ADDRESS) & 0x2FFE0000 ) == 0x20000000)
19         {
20           /* Jump to user application */
21           JumpAddress = *(__IO uint32_t*) (APPLICATION_ADDRESS + 4);
22           Jump_To_Application = (pFunction) JumpAddress;
23           /* Initialize user application's Stack Pointer */
24           __set_MSP(*(__IO uint32_t*) APPLICATION_ADDRESS);
25           Jump_To_Application();
26         }
27     }
28     
29     while(1)
30     {
31         GPIOD->ODR |= GPIO_Pin_13;
32         DelayMs(200);
33         GPIOD->ODR &= ~GPIO_Pin_13;
34         DelayMs(200);
35     }
36     
37 }

App2 程式碼

 1 int main(void)
 2 {
 3     Delay_Init();
 4     LED_Config();
 5     EXIT_GPIO_Config();
 6     printf("\n--------------------------------------------------\n");
 7     printf("\n                 STM32F4 IAP APP2                 \n");
 8     printf("\n--------------------------------------------------\n");
 9     
10     while(1)
11     {
12         GPIOD->ODR |= GPIO_Pin_12;
13         DelayMs(200);
14         GPIOD->ODR &= ~GPIO_Pin_12;
15         DelayMs(200);
16     }
17     
18 }

 App1 轉跳 App2 經過一個IO的判斷去決定是否轉跳, 在App2的程式碼內也要指定程式碼放的位置。

分別是 system_stm32f4xx.c 理頭的 VECT_TAB_OFFSET 必須修改成App2的位置

Flash 位置也要改成從0x8010000開始

轉跳代碼

 1     /* Flash unlock */
 2     FLASH_If_FlashUnlock();
 3 
 4     /* Test if User button on the Discovery kit is pressed */
 5     if (GPIO_ReadInputDataBit(GPIOA, GPIO_Pin_0) == Bit_RESET)
 6     {
 7         /* Check Vector Table: Test if user code is programmed starting from address 
 8            "APPLICATION_ADDRESS" */
 9         if (((*(__IO uint32_t*)APPLICATION_ADDRESS) & 0x2FFE0000 ) == 0x20000000)
10         {
11           /* Jump to user application */
12           JumpAddress = *(__IO uint32_t*) (APPLICATION_ADDRESS + 4);
13           Jump_To_Application = (pFunction) JumpAddress;
14           /* Initialize user application's Stack Pointer */
15           __set_MSP(*(__IO uint32_t*) APPLICATION_ADDRESS);
16           Jump_To_Application();
17         }
18     }

第9行 APPLICATION_ADDRESS必須定義成APP2 Flash 存放的Address, 這段代碼在STM官方網站理頭都下載得到

#define APPLICATION_ADDRESS        (uint32_t)0x08010000 
if (((*(__IO uint32_t*)APPLICATION_ADDRESS) & 0x2FFE0000 ) == 0x20000000)

在我的代碼裡頭, 在開機時只需要把 PA0 接到 GND, LED 閃爍的就是P12的LED。

App1 Code 位置從 0x8000000 開使堆疊(Stack)

App2 Code 位置從 0x8010000 開始堆疊(Stack)

 

posted on 2018-12-09 21:47  OO程式猿  阅读(679)  评论(0)  编辑  收藏  举报

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