STM32MP157——Remoteproc和RPMsg【轉】

轉自：https://hceng.cn/2020/05/09/STM32MP157%E2%80%94%E2%80%94Remoteproc%E5%92%8CRPMsg/

簡單介紹基於STM32MP157的Remoteproc和RPMsg框架。

STM32MP1系列產品，是STM32進軍Linux的首款微處理器，采用MCU+MPU的組合，集成兩顆主頻為650MHz的Cortex-A7應用處理器內核和一顆主頻為209MHz的Cortex-M4微控制器內核。

非對稱多處理Asymmetric Multiprocessing(AMP)雖然目前在嵌入式還不是主流，但未來肯定是趨勢。將多媒體處理扔給專用的MCU，亦或將對控制延時敏感的傳感器交給MCU實時控制，更多的組合給人更多的遐想。

對於非對稱多核架構，不同的核心是如何啟動運行，又是如何進行通信？這些疑惑在上手STM32MP157后，逐漸明朗，因此記錄下筆記。

1.生成M4固件

在進行啟動M4之前，需要先建立工程，生成M4固件，這里以點燈為例，簡單說下創建STM32MP157的M4工程。

這里要M4點燈，涉及到資源的分配，資源分配如下圖所示。

深藍色的IP為A7獨占，淺藍色的IP為M4獨占，豎線分割的IP為同一時刻只能一個占有，斜線分割的IP為任意時刻兩者可以同時占用。
比如這里GPIO就為兩者可以同時占用，在Linux中可以控制GPIO，同時M4也可控制GPIO。UART則為只能一個獨占，分配給M4后，A7將不能控制。

支持STM32開發的集成開發環境有很多，國內熟知的有Keil MDK-ARM和IAR EWAR。這兩個IDE都很好用，但它們都是商業軟件，免費或評估版要么有器件型號限制，要么有程序容量限制。於是出現了免費的Eclipse+GNU GCC來搭建STM32開發環境，但搭建過程繁瑣、版本差異大導致教程不統一，對新手很不友好。

STM32CubeIDE是ST公司基於Eclipse/CDT框架和GUN GCC工具鏈制作的免費IDE，並集成了STM32CubeMX。一個軟件就可以實現STM32系列芯片的外圍設備配置、代碼生成、代碼編輯、代碼編譯、在線調試，並且支持數百個Eclipse現有插件。

打開STM32CubeIDE，創建一個新的“STM32 Project”。

在彈出的STM32CubeMX，選擇“STM32MP157A”，具體型號以自己使用的開發板為准。注意這里的“芯片資料區”，提供了該型號的芯片手冊，不用再去網上找了。

再設置工程名字，打開STM32CubeMX的關聯視圖。

我使用的板子，LED燈接在PD13引腳上，因此這里把PD13設置為輸出引腳。

需要注意，這里還要選中該引腳，右鍵彈出“Pin Reservation”，選擇“Cortex-M4”，不然不會自動生成GPIO初始化代碼。

最后，如圖設置下GPIO的屬性。

設置完后，在標簽欄選擇“Project”->“Generate Code”，即可自動生成相關初始化代碼。默認的初始化代碼如下圖，需要注意的是“main.c”文件，在里面添加LED燈的控制邏輯。還有“stm32mp1xx_hal_gpio.c”，這個是hal庫源碼，從里面可知hal提供的GPIO相關操作函數，比如這里用到的HAL_GPIO_WritePin()。

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HAL_GPIO_WritePin(LED_BLUE_GPIO_Port, LED_BLUE_Pin, GPIO_PIN_SET); HAL_Delay( 1000); HAL_GPIO_WritePin(LED_BLUE_GPIO_Port, LED_BLUE_Pin, GPIO_PIN_RESET); HAL_Delay( 1000);

 

添加完LED的控制邏輯代碼后，在標簽欄選擇“Project”->“Build Project”即可編譯工程，得到GPIO_LED_CM4.elf。該文件就是M4的固件，包含Cortex-A7和Cortex-M4都可以訪問的資源表(.resource_table)和LED的控制程序等。

在Linux里，使用readelf -a GPIO_LED_CM4.elf命令，可以獲取ELF文件的更多信息。

2.Remoteproc框架

Remoteproc(Remote Processor Framework)，主要作用就是對遠程處理器的生命周期進行管理，即啟動、停止遠程處理器。
以STM32MP157為例，Cortex-A內核先啟動，然后使用Linux RemoteProc框架進行加載Cortex-M4固件，啟動M4內核。

ST官方提供的內核已經默認配置了Remoteproc驅動，進入系統后，首先將要運行的M4固件放在/lib/firmware/目錄下，然后將固件名字寫到/sys/class/remoteproc/remoteproc0/firmware，再操作/sys/class/remoteproc/remoteproc0/state啟動、停止M4處理器。

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[root@stm32mp157:~]# ls /lib/firmware/ DEMO_LED_CM4.elf [root@stm32mp157:~]# echo GPIO_LED_CM4.elf > /sys/class/remoteproc/remoteproc0/firmware [root@stm32mp157:~]# cat /sys/class/remoteproc/remoteproc0/state offline [root@stm32mp157:~]# echo start > /sys/class/remoteproc/remoteproc0/state [22683.222322] remoteproc remoteproc0: powering up m4 [22683.229097] remoteproc remoteproc0: Booting fw image GPIO_LED_CM4.elf, size 1899976 [22683.235549] remoteproc remoteproc0: header-less resource table [22683.241235] remoteproc remoteproc0: not resource table found for this firmware [22683.248749] remoteproc remoteproc0: header-less resource table [22683.254414] remoteproc remoteproc0: remote processor m4 is now up [root@stm32mp157:~]# echo stop > /sys/class/remoteproc/remoteproc0/state [22709.281733] remoteproc remoteproc0: warning: remote FW shutdown without ack [22709.287325] remoteproc remoteproc0: stopped remote processor m4

 

除了在Linux的用戶態控制M4內核的生命周期，還能在Linux內核態使用API控制(參考linux-origin_master/Documentation/remoteproc.txt)，甚至U-boot中控制。

3.RPMsg框架

Remoteproc框架實現了對遠程處理器生命周期的管理，RPMsg框架(Remote Processor Messaging Framework)則是實現對遠程處理器信息傳遞。
RPMsg是基於VirtIO的消息總線，它允許內核驅動程序與系統上可用的遠程處理器進行通信，同時，驅動程序可以根據需要公開適當的用戶空間接口(參考linux-origin_master/Documentation/rpmsg.txt)。

STM32MP1多核通信框架如下圖。

消息服務基於共享內存，使用RPMsg和Virtio框架，RemoteProc框架則控制遠程處理器生命周期。
信號通知(Mailbox)服務則基於內部IPCC(Inter-Processor communication controller)，ST提供OpenAMP相關庫。

這里列舉兩個示例：
第一個示例在Linux的用戶態和M4通信，實現A7控制M4的燈，A7和M4的相互喚醒；
第二個示例則是在Linux的內核態創建一個簡單的RPMsg客戶端，實現A7和M4的大量數據傳輸。

3.1 用戶態的通信

3.1.1 A7准備

ST官方提供的內核已經默認配置了RPMSG_TTY驅動，Linux這邊就不需要做什么了。
STM32MP1多核消息通信應用接口框圖如下，在RPMsg和Virtio框架創建一個面向用戶態的/dev/ttyRPMSG接口，M4在OpenAMP上創建虛擬串口，兩者最終效果像是串口透傳。

3.1.2 M4准備

創建一個STM32工程，在STM32CubeMX里，依次配置GPIO用於LED、配置UART5用於M4打印、以及配置IPCC和OPENAMP用於通信。

注意配置IPCC時，需要在NVIC Settings選項卡里，將IPCC RX1 occupied interrupt和IPCC TX1 free interrupt
的使能勾選上，不然后面的OPENAMP的Activated始終為灰色，無法激活。

生成初始化代碼后，在USER CODE BEGIN 0和USER CODE END 0之間添加printf的重定向函數，讓UART5與printf綁定。

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/* USER CODE BEGIN 0 */ #ifdef __GNUC__ /* With GCC/RAISONANCE, small printf (option LD Linker->Libraries->Small printf set to 'Yes') calls __io_putchar() */ #define PUTCHAR_PROTOTYPE int __io_putchar(int ch) #else #define PUTCHAR_PROTOTYPE int fputc(int ch, FILE *f) #endif /* __GNUC__ */ PUTCHAR_PROTOTYPE { /* Place your implementation of fputc here */ HAL_UART_Transmit(&huart5, ( uint8_t *)&ch, 1, HAL_MAX_DELAY); return ch; } /* USER CODE END 0 */

 

這里計划創建兩個RPMsg tty通道，一個用來LED控制命令，一個用來傳輸喚醒命令。

• 1.初始化兩個RPMsg tty虛擬串口

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if (VIRT_UART_Init(&huart0) != VIRT_UART_OK) { printf("VIRT_UART_Init UART0 failed.\r\n"); Error_Handler(); }   if (VIRT_UART_Init(&huart1) != VIRT_UART_OK) { printf("VIRT_UART_Init UART1 failed.\r\n"); Error_Handler(); }

• 2.注冊回調函數以按通道接收消息

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  if(VIRT_UART_RegisterCallback(&huart0, VIRT_UART_RXCPLT_CB_ID, VIRT_UART0_RxCpltCallback) != VIRT_UART_OK) { Error_Handler(); }   if(VIRT_UART_RegisterCallback(&huart1, VIRT_UART_RXCPLT_CB_ID, VIRT_UART1_RxCpltCallback) != VIRT_UART_OK) { Error_Handler(); }

• 3.編寫虛擬串口回調函數
  當RPMsg收到數據后，將調用該回調函數。在此函數里，需要將接收的數據復制到用戶內存，並修改接收標志位，通知用戶完成數據接收。

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  /* USER CODE BEGIN 4 */ void VIRT_UART0_RxCpltCallback(VIRT_UART_HandleTypeDef *huart) { printf("Msg received on VIRTUAL UART0 channel: %s \n\r", (char *) huart->pRxBuffPtr);   /* copy received msg in a variable to sent it back to master processor in main infinite loop*/ VirtUart0ChannelRxSize = huart->RxXferSize < MAX_BUFFER_SIZE? huart->RxXferSize : MAX_BUFFER_SIZE -1; memcpy(VirtUart0ChannelBuffRx, huart->pRxBuffPtr, VirtUart0ChannelRxSize); VirtUart0RxMsg = SET; }   void VIRT_UART1_RxCpltCallback(VIRT_UART_HandleTypeDef *huart) { printf("Msg received on VIRTUAL UART1 channel: %s \n\r", (char *) huart->pRxBuffPtr);   /* copy received msg in a variable to sent it back to master processor in main infinite loop*/ VirtUart1ChannelRxSize = huart->RxXferSize < MAX_BUFFER_SIZE? huart->RxXferSize : MAX_BUFFER_SIZE -1; memcpy(VirtUart1ChannelBuffRx, huart->pRxBuffPtr, VirtUart1ChannelRxSize); VirtUart1RxMsg = SET; } /* USER CODE END 4 */

• 4.主函數輪詢RPMsg消息
  OPENAMP_check_for_message()查詢MailBox狀態。
  當收到數據時，VIRT_UARTx_RxCpltCallback()會保存好收到數據，然后修改VirtUartxRxMsg標志位。
  主函數里發現VirtUartxRxMsg標志位發生變化時，即可獲取接收的數據。

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  while (1) { OPENAMP_check_for_message(); /* USER CODE END WHILE */   /* USER CODE BEGIN 3 */ if (VirtUart0RxMsg) { VirtUart0RxMsg = RESET;   /*VirUART0收到數據*/ }   if (VirtUart1RxMsg) { VirtUart1RxMsg = RESET;   /*VirUART1收到數據*/ } }

• 5.VirUART0接收控制LED指令
  每次VirtUart0RxMsg發生變化，說明VirUART0收到了數據。
  然后比較收到的數據內容，執行對應的操作。
  這里，M4收到MSG_LED_ON(*led_on)則打開LED燈，並發送消息給A7；M4收到MSG_LED_OFF(*led_off)則關閉LED燈，並發送消息給A7。

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  if (VirtUart0RxMsg) { VirtUart0RxMsg = RESET;   if (!strncmp((char *)VirtUart0ChannelBuffRx, MSG_LED_ON, strlen(MSG_LED_ON))) { strcpy((char *)BuffTx, "m4:led on\n"); printf("%s\r", BuffTx); VIRT_UART_Transmit(&huart0, BuffTx, strlen((const char *)BuffTx)); HAL_GPIO_WritePin(LED_BLUE_GPIO_Port, LED_BLUE_Pin, GPIO_PIN_RESET); }   if (!strncmp((char *)VirtUart0ChannelBuffRx, MSG_LED_OFF, strlen(MSG_LED_OFF))) { strcpy((char *)BuffTx, "m4:led off\n"); printf("%s\r", BuffTx); VIRT_UART_Transmit(&huart0, BuffTx, strlen((const char *)BuffTx)); HAL_GPIO_WritePin(LED_BLUE_GPIO_Port, LED_BLUE_Pin, GPIO_PIN_SET); } memset(VirtUart0ChannelBuffRx, 0 ,VirtUart0ChannelRxSize); memset(BuffTx, 0 ,strlen((const char *)BuffTx)); }

• 6.VirUART1接收休眠喚醒指令
  每次VirtUart1RxMsg發生變化，說明VirUART1收到了數據。
  然后比較收到的數據內容，執行對應的操作。
  這里，M4收到MSG_STOP(*stop)則進入CStop模式，中途A7再發任意數據給M4，由於IPCC也可設置為中斷喚醒源，將M4喚醒；M4收到MSG_DELAY(*delay)則等待20S后發數據給A7，在這20S內，將A7先休眠，隨后將被M4喚醒。

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  if (VirtUart1RxMsg) { VirtUart1RxMsg = RESET;   if (!strncmp((char *)VirtUart1ChannelBuffRx, MSG_STOP, strlen(MSG_STOP))) { strcpy((char *)BuffTx, "m4:stop\n"); printf("%s\r", BuffTx); VIRT_UART_Transmit(&huart1, BuffTx, strlen((const char *)BuffTx));   //RCC_backupClocks(); /* Clear the MCU flags before going into CSTOP */ SET_BIT(PWR->MCUCR, PWR_MCUCR_CSSF);   printf("Going to CStop mode\r\n"); /* (C)STOP protection mechanism * Only the IT with the highest priority (0 value) can interrupt. * RCC_WAKEUP_IRQn IT is intended to have the highest priority and to be the * only one IT having this value * RCC_WAKEUP_IRQn is generated only when RCC is completely resumed from * CSTOP */ __set_BASEPRI( 1 << (8 - __NVIC_PRIO_BITS));   HAL_PWR_EnterSTOPMode(PWR_MAINREGULATOR_ON, PWR_STOPENTRY_WFI);   /* To allow Systick to increment after CSTOP (Eg.: to not block during * TIMEOUT routines), TICK_INT_PRIORITY < BASEPRI * For this example as TICK_INT_PRIORITY = 1, BASEPRI should be 2 */ __set_BASEPRI( 2 << (8 - __NVIC_PRIO_BITS));   printf("Leaving CStop mode\r\n");   /* Test if system was on STOP mode */ if( (PWR->MCUCR & PWR_MCUCR_STOPF) == PWR_MCUCR_STOPF) { printf("System was on STOP mode\r\n");   /* Clear the MCU flags */ SET_BIT(PWR->MCUCR, PWR_MCUCR_CSSF);   /* Restore clocks */ /* if (RCC_restoreClocks() == HAL_OK) { printf("CM4 restored clocks successfully\r\n"); } */ }   /* All level of ITs can interrupt */ __set_BASEPRI( 0U); }   if (!strncmp((char *)VirtUart1ChannelBuffRx, MSG_DELAY, strlen(MSG_DELAY))) { printf("Waiting 20 secs before sending the answer message\r\n"); HAL_Delay( 20 *1000);   strcpy((char *)BuffTx, "m4:wakeup A7\n"); printf("%s\r", BuffTx); VIRT_UART_Transmit(&huart1, BuffTx, strlen((const char *)BuffTx)); } memset(VirtUart1ChannelBuffRx, 0 ,VirtUart1ChannelRxSize); memset(BuffTx, 0 ,strlen((const char *)BuffTx)); }

為了A7能發消息將M4喚醒，還需要IPCC作為M4的中斷喚醒源。

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EXTI_ConfigTypeDef EXTI_ConfigStructure; EXTI_HandleTypeDef hexti62; /* * Set configuration of Exti line 62 (IPCC interrupt CPU2). It could be used to wakeup the * M4 from CStop mode when RPMsg received from Cortex-A7 */ EXTI_ConfigStructure.Line = EXTI_LINE_62; EXTI_ConfigStructure.Mode = EXTI_MODE_C2_INTERRUPT; //PERIPH_LOCK(EXTI); HAL_EXTI_SetConfigLine(&hexti62, &EXTI_ConfigStructure); //PERIPH_UNLOCK(EXTI);   /* * Enable RCC_IT_WKUP to exit M4 from CStop mode. * Indeed, due to SOC issue, M4 firmware shall make sure * RCC_WAKEUP interrupt is the first one used to exit M4 from CStop mode. * Therefore, M4 masks all NVIC interrupts with priority higher than 0 * before entering CStop mode and unmasks them when moving from WFI. * (in HAL_PWR_EnterSTOPMode function) * Note: All other NVIC interrupts shall be set to a different value * from 0 to make sure that this workaround works well. */ __HAL_RCC_ENABLE_IT(RCC_IT_WKUP);

 

3.1.3 M4完整代碼

[main.c]

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/* USER CODE BEGIN Header */ /** ****************************************************************************** * @file : main.c * @brief : Main program body ****************************************************************************** * @attention * * <h2><center>&copy; Copyright (c) 2020 STMicroelectronics. * All rights reserved.</center></h2> * * This software component is licensed by ST under BSD 3-Clause license, * the "License"; You may not use this file except in compliance with the * License. You may obtain a copy of the License at: * opensource.org/licenses/BSD-3-Clause * ****************************************************************************** */ /* USER CODE END Header */   /* Includes ------------------------------------------------------------------*/ #include "main.h" #include "openamp.h"   /* Private includes ----------------------------------------------------------*/ /* USER CODE BEGIN Includes */ #include "virt_uart.h" /* USER CODE END Includes */   /* Private typedef -----------------------------------------------------------*/ /* USER CODE BEGIN PTD */   /* USER CODE END PTD */   /* Private define ------------------------------------------------------------*/ /* USER CODE BEGIN PD */ #define MAX_BUFFER_SIZE RPMSG_BUFFER_SIZE /* USER CODE END PD */   /* Private macro -------------------------------------------------------------*/ /* USER CODE BEGIN PM */   /* USER CODE END PM */   /* Private variables ---------------------------------------------------------*/ IPCC_HandleTypeDef hipcc;   UART_HandleTypeDef huart5;   /* USER CODE BEGIN PV */ VIRT_UART_HandleTypeDef huart0; VIRT_UART_HandleTypeDef huart1;   __IO FlagStatus VirtUart0RxMsg = RESET; uint8_t VirtUart0ChannelBuffRx[MAX_BUFFER_SIZE]; uint16_t VirtUart0ChannelRxSize = 0;   __IO FlagStatus VirtUart1RxMsg = RESET; uint8_t VirtUart1ChannelBuffRx[MAX_BUFFER_SIZE]; uint16_t VirtUart1ChannelRxSize = 0;   uint8_t BuffTx[MAX_BUFFER_SIZE];   #define MSG_LED_ON "*led_on" #define MSG_LED_OFF "*led_off" #define MSG_STOP "*stop" #define MSG_DELAY "*delay" /* USER CODE END PV */   /* Private function prototypes -----------------------------------------------*/ void SystemClock_Config(void); static void MX_GPIO_Init(void); static void MX_IPCC_Init(void); static void MX_UART5_Init(void); int MX_OPENAMP_Init(int RPMsgRole, rpmsg_ns_bind_cb ns_bind_cb); /* USER CODE BEGIN PFP */ void VIRT_UART0_RxCpltCallback(VIRT_UART_HandleTypeDef *huart); void VIRT_UART1_RxCpltCallback(VIRT_UART_HandleTypeDef *huart); /* USER CODE END PFP */   /* Private user code ---------------------------------------------------------*/ /* USER CODE BEGIN 0 */ #ifdef __GNUC__ /* With GCC/RAISONANCE, small printf (option LD Linker->Libraries->Small printf set to 'Yes') calls __io_putchar() */ #define PUTCHAR_PROTOTYPE int __io_putchar(int ch) #else #define PUTCHAR_PROTOTYPE int fputc(int ch, FILE *f) #endif /* __GNUC__ */ PUTCHAR_PROTOTYPE { /* Place your implementation of fputc here */ HAL_UART_Transmit(&huart5, ( uint8_t *)&ch, 1, HAL_MAX_DELAY); return ch; } /* USER CODE END 0 */   /** * @brief The application entry point. * @retval int */ int main(void) { /* USER CODE BEGIN 1 */   /* USER CODE END 1 */   /* MCU Configuration--------------------------------------------------------*/   /* Reset of all peripherals, Initializes the Flash interface and the Systick. */ HAL_Init();   /* USER CODE BEGIN Init */   /* USER CODE END Init */   if(IS_ENGINEERING_BOOT_MODE()) { /* Configure the system clock */ SystemClock_Config(); }   /* IPCC initialisation */ MX_IPCC_Init(); /* OpenAmp initialisation ---------------------------------*/ MX_OPENAMP_Init(RPMSG_REMOTE, NULL);   /* USER CODE BEGIN SysInit */   /* USER CODE END SysInit */   /* Initialize all configured peripherals */ MX_GPIO_Init(); MX_UART5_Init(); /* USER CODE BEGIN 2 */ printf("RPMsg user mode test\r\n");   if (VIRT_UART_Init(&huart0) != VIRT_UART_OK) { printf("VIRT_UART_Init UART0 failed.\r\n"); Error_Handler(); }   if (VIRT_UART_Init(&huart1) != VIRT_UART_OK) { printf("VIRT_UART_Init UART1 failed.\r\n"); Error_Handler(); }   if(VIRT_UART_RegisterCallback(&huart0, VIRT_UART_RXCPLT_CB_ID, VIRT_UART0_RxCpltCallback) != VIRT_UART_OK) { Error_Handler(); }   if(VIRT_UART_RegisterCallback(&huart1, VIRT_UART_RXCPLT_CB_ID, VIRT_UART1_RxCpltCallback) != VIRT_UART_OK) { Error_Handler(); }   EXTI_ConfigTypeDef EXTI_ConfigStructure; EXTI_HandleTypeDef hexti62; /* * Set configuration of Exti line 62 (IPCC interrupt CPU2). It could be used to wakeup the * M4 from CStop mode when RPMsg received from Cortex-A7 */ EXTI_ConfigStructure.Line = EXTI_LINE_62; EXTI_ConfigStructure.Mode = EXTI_MODE_C2_INTERRUPT; //PERIPH_LOCK(EXTI); HAL_EXTI_SetConfigLine(&hexti62, &EXTI_ConfigStructure); //PERIPH_UNLOCK(EXTI);   /* * Enable RCC_IT_WKUP to exit M4 from CStop mode. * Indeed, due to SOC issue, M4 firmware shall make sure * RCC_WAKEUP interrupt is the first one used to exit M4 from CStop mode. * Therefore, M4 masks all NVIC interrupts with priority higher than 0 * before entering CStop mode and unmasks them when moving from WFI. * (in HAL_PWR_EnterSTOPMode function) * Note: All other NVIC interrupts shall be set to a different value * from 0 to make sure that this workaround works well. */ __HAL_RCC_ENABLE_IT(RCC_IT_WKUP); /* USER CODE END 2 */   /* Infinite loop */ /* USER CODE BEGIN WHILE */ while (1) { OPENAMP_check_for_message(); /* USER CODE END WHILE */   /* USER CODE BEGIN 3 */ if (VirtUart0RxMsg) { VirtUart0RxMsg = RESET;   if (!strncmp((char *)VirtUart0ChannelBuffRx, MSG_LED_ON, strlen(MSG_LED_ON))) { strcpy((char *)BuffTx, "m4:led on\n"); printf("%s\r", BuffTx); VIRT_UART_Transmit(&huart0, BuffTx, strlen((const char *)BuffTx)); HAL_GPIO_WritePin(LED_BLUE_GPIO_Port, LED_BLUE_Pin, GPIO_PIN_RESET); }   if (!strncmp((char *)VirtUart0ChannelBuffRx, MSG_LED_OFF, strlen(MSG_LED_OFF))) { strcpy((char *)BuffTx, "m4:led off\n"); printf("%s\r", BuffTx); VIRT_UART_Transmit(&huart0, BuffTx, strlen((const char *)BuffTx)); HAL_GPIO_WritePin(LED_BLUE_GPIO_Port, LED_BLUE_Pin, GPIO_PIN_SET); } memset(VirtUart0ChannelBuffRx, 0 ,VirtUart0ChannelRxSize); memset(BuffTx, 0 ,strlen((const char *)BuffTx)); }   if (VirtUart1RxMsg) { VirtUart1RxMsg = RESET;   if (!strncmp((char *)VirtUart1ChannelBuffRx, MSG_STOP, strlen(MSG_STOP))) { strcpy((char *)BuffTx, "m4:stop\n"); printf("%s\r", BuffTx); VIRT_UART_Transmit(&huart1, BuffTx, strlen((const char *)BuffTx));   //RCC_backupClocks(); /* Clear the MCU flags before going into CSTOP */ SET_BIT(PWR->MCUCR, PWR_MCUCR_CSSF);   printf("Going to CStop mode\r\n"); /* (C)STOP protection mechanism * Only the IT with the highest priority (0 value) can interrupt. * RCC_WAKEUP_IRQn IT is intended to have the highest priority and to be the * only one IT having this value * RCC_WAKEUP_IRQn is generated only when RCC is completely resumed from * CSTOP */ __set_BASEPRI( 1 << (8 - __NVIC_PRIO_BITS));   HAL_PWR_EnterSTOPMode(PWR_MAINREGULATOR_ON, PWR_STOPENTRY_WFI);   /* To allow Systick to increment after CSTOP (Eg.: to not block during * TIMEOUT routines), TICK_INT_PRIORITY < BASEPRI * For this example as TICK_INT_PRIORITY = 1, BASEPRI should be 2 */ __set_BASEPRI( 2 << (8 - __NVIC_PRIO_BITS));   printf("Leaving CStop mode\r\n");   /* Test if system was on STOP mode */ if( (PWR->MCUCR & PWR_MCUCR_STOPF) == PWR_MCUCR_STOPF) { printf("System was on STOP mode\r\n");   /* Clear the MCU flags */ SET_BIT(PWR->MCUCR, PWR_MCUCR_CSSF);   /* Restore clocks */ /* if (RCC_restoreClocks() == HAL_OK) { printf("CM4 restored clocks successfully\r\n"); } */ }   /* All level of ITs can interrupt */ __set_BASEPRI( 0U); }   if (!strncmp((char *)VirtUart1ChannelBuffRx, MSG_DELAY, strlen(MSG_DELAY))) { printf("Waiting 20 secs before sending the answer message\r\n"); HAL_Delay( 20 *1000);   strcpy((char *)BuffTx, "m4:wakeup A7\n"); printf("%s\r", BuffTx); VIRT_UART_Transmit(&huart1, BuffTx, strlen((const char *)BuffTx)); } memset(VirtUart1ChannelBuffRx, 0 ,VirtUart1ChannelRxSize); memset(BuffTx, 0 ,strlen((const char *)BuffTx)); }   } /* USER CODE END 3 */ }   /** * @brief System Clock Configuration * @retval None */ void SystemClock_Config(void) { RCC_OscInitTypeDef RCC_OscInitStruct = { 0}; RCC_ClkInitTypeDef RCC_ClkInitStruct = { 0};   /** Initializes the CPU, AHB and APB busses clocks */ RCC_OscInitStruct.OscillatorType = RCC_OSCILLATORTYPE_HSI|RCC_OSCILLATORTYPE_LSI; RCC_OscInitStruct.HSIState = RCC_HSI_ON; RCC_OscInitStruct.HSICalibrationValue = 16; RCC_OscInitStruct.HSIDivValue = RCC_HSI_DIV1; RCC_OscInitStruct.LSIState = RCC_LSI_ON; RCC_OscInitStruct.PLL.PLLState = RCC_PLL_NONE; RCC_OscInitStruct.PLL2.PLLState = RCC_PLL_NONE; RCC_OscInitStruct.PLL3.PLLState = RCC_PLL_NONE; RCC_OscInitStruct.PLL4.PLLState = RCC_PLL_NONE; if (HAL_RCC_OscConfig(&RCC_OscInitStruct) != HAL_OK) { Error_Handler(); } /** RCC Clock Config */ RCC_ClkInitStruct.ClockType = RCC_CLOCKTYPE_HCLK|RCC_CLOCKTYPE_ACLK |RCC_CLOCKTYPE_PCLK1|RCC_CLOCKTYPE_PCLK2 |RCC_CLOCKTYPE_PCLK3|RCC_CLOCKTYPE_PCLK4 |RCC_CLOCKTYPE_PCLK5; RCC_ClkInitStruct.AXISSInit.AXI_Clock = RCC_AXISSOURCE_HSI; RCC_ClkInitStruct.AXISSInit.AXI_Div = RCC_AXI_DIV1; RCC_ClkInitStruct.MCUInit.MCU_Clock = RCC_MCUSSOURCE_HSI; RCC_ClkInitStruct.MCUInit.MCU_Div = RCC_MCU_DIV1; RCC_ClkInitStruct.APB4_Div = RCC_APB4_DIV1; RCC_ClkInitStruct.APB5_Div = RCC_APB5_DIV1; RCC_ClkInitStruct.APB1_Div = RCC_APB1_DIV1; RCC_ClkInitStruct.APB2_Div = RCC_APB2_DIV1; RCC_ClkInitStruct.APB3_Div = RCC_APB3_DIV1;   if (HAL_RCC_ClockConfig(&RCC_ClkInitStruct) != HAL_OK) { Error_Handler(); } }   /** * @brief IPCC Initialization Function * @param None * @retval None */ static void MX_IPCC_Init(void) {   /* USER CODE BEGIN IPCC_Init 0 */   /* USER CODE END IPCC_Init 0 */   /* USER CODE BEGIN IPCC_Init 1 */   /* USER CODE END IPCC_Init 1 */ hipcc.Instance = IPCC; if (HAL_IPCC_Init(&hipcc) != HAL_OK) { Error_Handler(); } /* USER CODE BEGIN IPCC_Init 2 */   /* USER CODE END IPCC_Init 2 */   }   /** * @brief UART5 Initialization Function * @param None * @retval None */ static void MX_UART5_Init(void) {   /* USER CODE BEGIN UART5_Init 0 */   /* USER CODE END UART5_Init 0 */   /* USER CODE BEGIN UART5_Init 1 */   /* USER CODE END UART5_Init 1 */ huart5.Instance = UART5; huart5.Init.BaudRate = 115200; huart5.Init.WordLength = UART_WORDLENGTH_8B; huart5.Init.StopBits = UART_STOPBITS_1; huart5.Init.Parity = UART_PARITY_NONE; huart5.Init.Mode = UART_MODE_TX_RX; huart5.Init.HwFlowCtl = UART_HWCONTROL_NONE; huart5.Init.OverSampling = UART_OVERSAMPLING_16; huart5.Init.OneBitSampling = UART_ONE_BIT_SAMPLE_DISABLE; huart5.Init.ClockPrescaler = UART_PRESCALER_DIV1; huart5.AdvancedInit.AdvFeatureInit = UART_ADVFEATURE_NO_INIT; if (HAL_UART_Init(&huart5) != HAL_OK) { Error_Handler(); } if (HAL_UARTEx_SetTxFifoThreshold(&huart5, UART_TXFIFO_THRESHOLD_1_8) != HAL_OK) { Error_Handler(); } if (HAL_UARTEx_SetRxFifoThreshold(&huart5, UART_RXFIFO_THRESHOLD_1_8) != HAL_OK) { Error_Handler(); } if (HAL_UARTEx_DisableFifoMode(&huart5) != HAL_OK) { Error_Handler(); } /* USER CODE BEGIN UART5_Init 2 */   /* USER CODE END UART5_Init 2 */   }   /** * @brief GPIO Initialization Function * @param None * @retval None */ static void MX_GPIO_Init(void) { GPIO_InitTypeDef GPIO_InitStruct = { 0};   /* GPIO Ports Clock Enable */ __HAL_RCC_GPIOB_CLK_ENABLE(); __HAL_RCC_GPIOD_CLK_ENABLE();   /*Configure GPIO pin : LED_BLUE_Pin */ GPIO_InitStruct.Pin = LED_BLUE_Pin; GPIO_InitStruct.Mode = GPIO_MODE_OUTPUT_PP; GPIO_InitStruct.Pull = GPIO_PULLUP; GPIO_InitStruct.Speed = GPIO_SPEED_FREQ_VERY_HIGH; HAL_GPIO_Init(LED_BLUE_GPIO_Port, &GPIO_InitStruct);   }   /* USER CODE BEGIN 4 */ void VIRT_UART0_RxCpltCallback(VIRT_UART_HandleTypeDef *huart) { printf("Msg received on VIRTUAL UART0 channel: %s \r\n", (char *) huart->pRxBuffPtr);   /* copy received msg in a variable to sent it back to master processor in main infinite loop*/ VirtUart0ChannelRxSize = huart->RxXferSize < MAX_BUFFER_SIZE? huart->RxXferSize : MAX_BUFFER_SIZE -1; memcpy(VirtUart0ChannelBuffRx, huart->pRxBuffPtr, VirtUart0ChannelRxSize); VirtUart0RxMsg = SET; }   void VIRT_UART1_RxCpltCallback(VIRT_UART_HandleTypeDef *huart) { printf("Msg received on VIRTUAL UART1 channel: %s \r\n", (char *) huart->pRxBuffPtr);   /* copy received msg in a variable to sent it back to master processor in main infinite loop*/ VirtUart1ChannelRxSize = huart->RxXferSize < MAX_BUFFER_SIZE? huart->RxXferSize : MAX_BUFFER_SIZE -1; memcpy(VirtUart1ChannelBuffRx, huart->pRxBuffPtr, VirtUart1ChannelRxSize); VirtUart1RxMsg = SET; } /* USER CODE END 4 */   /** * @brief This function is executed in case of error occurrence. * @retval None */ void Error_Handler(void) { /* USER CODE BEGIN Error_Handler_Debug */ /* User can add his own implementation to report the HAL error return state */   /* USER CODE END Error_Handler_Debug */ }   #ifdef USE_FULL_ASSERT /** * @brief Reports the name of the source file and the source line number * where the assert_param error has occurred. * @param file: pointer to the source file name * @param line: assert_param error line source number * @retval None */ void assert_failed(uint8_t *file, uint32_t line) { /* USER CODE BEGIN 6 */ /* User can add his own implementation to report the file name and line number, tex: printf("Wrong parameters value: file %s on line %d\r\n", file, line) */ /* USER CODE END 6 */ } #endif /* USE_FULL_ASSERT */   /************************ (C) COPYRIGHT STMicroelectronics *****END OF FILE****/

3.1.4 測試效果

• 1.測試A7命令M4控制LED燈
  首先將前面編譯生成的rpmsg_user_CM4.elf放在/lib/firmware目錄下。
  然后啟動固件，此時看到打印信息里提示創建了兩個通道ttyRPMSG0和ttyRPMSG1，同時M4也打印了測試開始信息。

  1 2 3

  cd /sys/class/remoteproc/remoteproc0 echo rpmsg_user_CM4.elf > firmware echo start > state

然后還需要設置虛擬串口/dev/ttyRPMSG0。
-onlcr是不將NL字符映射為CR-NL字符，就是說發送給M4的數據，不會自動加上回車，不然這里發送led_on，M4收到的為led_on\n\r，正確的應該是收到*led_on\r。
-echo是禁止回顯，以方便查看接收的字符。

1 2	stty -onlcr -echo -F /dev/ttyRPMSG0 cat /dev/ttyRPMSG0 &

 

最后，向/dev/ttyRPMSG0寫入預定義的指令，M4收到指令便會控制LED燈，並發送結果給A7。

1 2	echo "*led_on" > /dev/ttyRPMSG0 echo "*led_off" > /dev/ttyRPMSG0

 

• 2.測試A7和M4休眠喚醒
  接着前面，啟動M4后。
  首先設置虛擬串口/dev/ttyRPMSG1。

  1 2	stty -onlcr -echo -F /dev/ttyRPMSG1 cat /dev/ttyRPMSG1 &

然后向/dev/ttyRPMSG1寫入*stop，M4隨后卡在打印Going to CStop mode后，接着向/dev/ttyRPMSG1寫入wakeup(任意字符即可)，M4隨后打印Leaving CStop mode。即實現了A7控制M4的休眠和喚醒。

1 2	echo "*stop" > /dev/ttyRPMSG1 echo "wakeup" >/dev/ttyRPMSG1

 

再測試M4喚醒A7。
先使能A7喚醒，然后向/dev/ttyRPMSG1寫入*delay，M4收到指令后，20S后會向A7發數據，從而喚醒A7。
此時控制A7進入休眠狀態，20S后，A7被喚醒。

1 2 3

echo enabled > /sys/devices/platform/soc/4c001000.mailbox/power/wakeup echo "*delay" > /dev/ttyRPMSG1 echo mem > /sys/power/state

 

3.2 內核態的通信

3.2.1 A7准備

內核已經提供了示例驅動程序linux-origin_master/samples/rpmsg/rpmsg_client_sample.c，這里直接使用該驅動，簡單的修改了下打印內容，方便查看。

[rpmsg_client_sample.c]

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/* * Remote processor messaging - sample client driver * * Copyright (C) 2011 Texas Instruments, Inc. * Copyright (C) 2011 Google, Inc. * * Ohad Ben-Cohen <[e-mail]> * Brian Swetland <[e-mail]> * * This software is licensed under the terms of the GNU General Public * License version 2, as published by the Free Software Foundation, and * may be copied, distributed, and modified under those terms. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. */   #include <linux/kernel.h> #include <linux/module.h> #include <linux/rpmsg.h>   #define MSG "hello world! A7->M4" #define MSG_LIMIT 100   struct instance_data { int rx_count; };   static int rpmsg_sample_cb(struct rpmsg_device *rpdev, void *data, int len, void *priv, u32 src) { int ret; struct instance_data *idata = dev_get_drvdata(&rpdev->dev);   //dev_info(&rpdev->dev, "incoming msg %d (src: 0x%x)\n", ++idata->rx_count, src); //print_hex_dump(KERN_DEBUG, __func__, DUMP_PREFIX_NONE, 16, 1, data, len, true);   printk(KERN_DEBUG "received_rpmsg: %s %d \n", data, ++idata->rx_count);     /* samples should not live forever */ if (idata->rx_count >= MSG_LIMIT) { //dev_info(&rpdev->dev, "goodbye!\n"); return 0; }   /* send a new message now */ ret = rpmsg_send(rpdev->ept, MSG, strlen(MSG)); if (ret) dev_err(&rpdev->dev, "rpmsg_send failed: %d\n", ret); else printk(KERN_DEBUG "send_rpmsg: %s \n", MSG);   return 0; }   static int rpmsg_sample_probe(struct rpmsg_device *rpdev) { int ret; struct instance_data *idata;   dev_info(&rpdev->dev, "new channel: 0x%x -> 0x%x!\n", rpdev->src, rpdev->dst);   idata = devm_kzalloc(&rpdev->dev, sizeof(*idata), GFP_KERNEL); if (!idata) return -ENOMEM;   dev_set_drvdata(&rpdev->dev, idata);   /* send a message to our remote processor */ ret = rpmsg_send(rpdev->ept, MSG, strlen(MSG)); if (ret) { dev_err(&rpdev->dev, "rpmsg_send failed: %d\n", ret); return ret; } else printk(KERN_DEBUG "send_rpmsg: %s \n", MSG);   return 0; }   static void rpmsg_sample_remove(struct rpmsg_device *rpdev) { dev_info(&rpdev->dev, "rpmsg sample client driver is removed\n"); }   static struct rpmsg_device_id rpmsg_driver_sample_id_table[] = { { .name = "rpmsg-client-sample" }, { }, }; MODULE_DEVICE_TABLE(rpmsg, rpmsg_driver_sample_id_table);   static struct rpmsg_driver rpmsg_sample_client = { .drv.name = KBUILD_MODNAME, .id_table = rpmsg_driver_sample_id_table, .probe = rpmsg_sample_probe, .callback = rpmsg_sample_cb, .remove = rpmsg_sample_remove, }; module_rpmsg_driver(rpmsg_sample_client);   MODULE_DESCRIPTION( "Remote processor messaging sample client driver"); MODULE_LICENSE( "GPL v2");

 

驅動比較簡單，核心是rpmsg_sample_cb()，rpmsg收到數據后將回調該函數。
從data獲得M4發來的數據，通過rpmsg_send()將數據發給M4。
將該驅動編譯成模塊，並在A7中加載。

3.2.2 M4准備

參考前面的示例，依次在STM32CubeMX配置UART5、IPCC和OPENAMP，然后生成初始化代碼。

• 1.建一個rpmsg通道

  1	OPENAMP_create_endpoint(&resmgr_ept, RPMSG_SERVICE_NAME, RPMSG_ADDR_ANY, rx_callback, NULL);

注意這里的RPMSG_SERVICE_NAME和驅動里rpmsg_device_id結構體的.name的名字一樣。
之后，一旦rpmsg通道數據，將回調rx_callback()函數。

• 2.編寫接收回調函數
  此函數里，需要將接收的數據復制到用戶內存，並修改接收標志位。

  1 2 3 4 5 6 7

  static int rx_callback(struct rpmsg_endpoint *rp_chnl, void *data, size_t len, uint32_t src, void *priv) { /* copy received msg, and raise a flag */ memcpy(received_rpmsg, data, len > sizeof(received_rpmsg) ? sizeof(received_rpmsg) : len); printf("received_rpmsg=%s\r\n", received_rpmsg); rx_status = SET; return 0;

• 3.主函數輪詢RPMsg消息
  OPENAMP_check_for_message()查詢MailBox狀態。
  當收到數據時，rx_callback()會保存好收到數據，然后修改rx_status標志位。
  主函數里發現rx_status標志位發生變化時，即可獲取接收的數據。

  1 2 3 4 5 6 7 8 9 10 11 12 13

  while (1) { OPENAMP_check_for_message(); /* USER CODE END WHILE */ if (rx_status == SET) { /* Message received: send back a message anwser */ rx_status = RESET;   /*rpmsg收到數據*/ } /* USER CODE BEGIN 3 */ }

• 4.向M4發送數據
  使用OPENAMP_send()向A7發送數據。

  1 2 3 4 5 6 7 8 9 10 11 12

  if (++count < 100) sprintf((char *)msg, "hello world! M4->A7 %02ld", count); else strcpy((char *)msg, "goodbye!");   if (OPENAMP_send(&resmgr_ept, msg, strlen((char *)msg) + 1) < 0) { printf("Failed to send message\r\n"); Error_Handler(); } else printf("send_rpmsg=%s\r\n", msg);

3.2.3 M4完整代碼

[main.c]

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/* USER CODE BEGIN Header */ /** ****************************************************************************** * @file : main.c * @brief : Main program body ****************************************************************************** * @attention * * <h2><center>&copy; Copyright (c) 2020 STMicroelectronics. * All rights reserved.</center></h2> * * This software component is licensed by ST under BSD 3-Clause license, * the "License"; You may not use this file except in compliance with the * License. You may obtain a copy of the License at: * opensource.org/licenses/BSD-3-Clause * ****************************************************************************** */ /* USER CODE END Header */   /* Includes ------------------------------------------------------------------*/ #include "main.h" #include "openamp.h"   /* Private includes ----------------------------------------------------------*/ /* USER CODE BEGIN Includes */   /* USER CODE END Includes */   /* Private typedef -----------------------------------------------------------*/ /* USER CODE BEGIN PTD */   /* USER CODE END PTD */   /* Private define ------------------------------------------------------------*/ /* USER CODE BEGIN PD */ #define RPMSG_SERVICE_NAME "rpmsg-client-sample" /* USER CODE END PD */   /* Private macro -------------------------------------------------------------*/ /* USER CODE BEGIN PM */   /* USER CODE END PM */   /* Private variables ---------------------------------------------------------*/ IPCC_HandleTypeDef hipcc;   UART_HandleTypeDef huart5;   /* USER CODE BEGIN PV */ __IO FlagStatus rx_status = RESET; uint8_t received_rpmsg[128]; /* USER CODE END PV */   /* Private function prototypes -----------------------------------------------*/ void SystemClock_Config(void); static void MX_GPIO_Init(void); static void MX_IPCC_Init(void); static void MX_UART5_Init(void); int MX_OPENAMP_Init(int RPMsgRole, rpmsg_ns_bind_cb ns_bind_cb); /* USER CODE BEGIN PFP */ static int rx_callback(struct rpmsg_endpoint *rp_chnl, void *data, size_t len, uint32_t src, void *priv); /* USER CODE END PFP */   /* Private user code ---------------------------------------------------------*/ /* USER CODE BEGIN 0 */ #ifdef __GNUC__ /* With GCC/RAISONANCE, small printf (option LD Linker->Libraries->Small printf set to 'Yes') calls __io_putchar() */ #define PUTCHAR_PROTOTYPE int __io_putchar(int ch) #else #define PUTCHAR_PROTOTYPE int fputc(int ch, FILE *f) #endif /* __GNUC__ */ PUTCHAR_PROTOTYPE { /* Place your implementation of fputc here */ HAL_UART_Transmit(&huart5, ( uint8_t *)&ch, 1, HAL_MAX_DELAY); return ch; } /* USER CODE END 0 */   /** * @brief The application entry point. * @retval int */ int main(void) { /* USER CODE BEGIN 1 */ struct rpmsg_endpoint resmgr_ept; uint32_t count = 0; uint8_t msg[32]; /* USER CODE END 1 */   /* MCU Configuration--------------------------------------------------------*/   /* Reset of all peripherals, Initializes the Flash interface and the Systick. */ HAL_Init();   /* USER CODE BEGIN Init */   /* USER CODE END Init */   if(IS_ENGINEERING_BOOT_MODE()) { /* Configure the system clock */ SystemClock_Config(); }   /* IPCC initialisation */ MX_IPCC_Init(); /* OpenAmp initialisation ---------------------------------*/ MX_OPENAMP_Init(RPMSG_REMOTE, NULL);   /* USER CODE BEGIN SysInit */   /* USER CODE END SysInit */   /* Initialize all configured peripherals */ MX_GPIO_Init(); MX_UART5_Init(); /* USER CODE BEGIN 2 */ printf("RPMsg kernel mode test\r\n"); /* Create an rpmsg channel to communicate with the Master processor CPU1(CA7) */ OPENAMP_create_endpoint(&resmgr_ept, RPMSG_SERVICE_NAME, RPMSG_ADDR_ANY, rx_callback, NULL); /* USER CODE END 2 */   /* Infinite loop */ /* USER CODE BEGIN WHILE */ while (1) { OPENAMP_check_for_message(); /* USER CODE END WHILE */ if (rx_status == SET) { /* Message received: send back a message anwser */ rx_status = RESET;   if (++count < 100) sprintf((char *)msg, "hello world! M4->A7 %02ld", count); else strcpy((char *)msg, "goodbye!");   if (OPENAMP_send(&resmgr_ept, msg, strlen((char *)msg) + 1) < 0) { printf("Failed to send message\r\n"); Error_Handler(); } else printf("send_rpmsg=%s\r\n", msg); } /* USER CODE BEGIN 3 */ } /* USER CODE END 3 */ }   /** * @brief System Clock Configuration * @retval None */ void SystemClock_Config(void) { RCC_OscInitTypeDef RCC_OscInitStruct = { 0}; RCC_ClkInitTypeDef RCC_ClkInitStruct = { 0};   /** Initializes the CPU, AHB and APB busses clocks */ RCC_OscInitStruct.OscillatorType = RCC_OSCILLATORTYPE_HSI|RCC_OSCILLATORTYPE_LSI; RCC_OscInitStruct.HSIState = RCC_HSI_ON; RCC_OscInitStruct.HSICalibrationValue = 16; RCC_OscInitStruct.HSIDivValue = RCC_HSI_DIV1; RCC_OscInitStruct.LSIState = RCC_LSI_ON; RCC_OscInitStruct.PLL.PLLState = RCC_PLL_NONE; RCC_OscInitStruct.PLL2.PLLState = RCC_PLL_NONE; RCC_OscInitStruct.PLL3.PLLState = RCC_PLL_NONE; RCC_OscInitStruct.PLL4.PLLState = RCC_PLL_NONE; if (HAL_RCC_OscConfig(&RCC_OscInitStruct) != HAL_OK) { Error_Handler(); } /** RCC Clock Config */ RCC_ClkInitStruct.ClockType = RCC_CLOCKTYPE_HCLK|RCC_CLOCKTYPE_ACLK |RCC_CLOCKTYPE_PCLK1|RCC_CLOCKTYPE_PCLK2 |RCC_CLOCKTYPE_PCLK3|RCC_CLOCKTYPE_PCLK4 |RCC_CLOCKTYPE_PCLK5; RCC_ClkInitStruct.AXISSInit.AXI_Clock = RCC_AXISSOURCE_HSI; RCC_ClkInitStruct.AXISSInit.AXI_Div = RCC_AXI_DIV1; RCC_ClkInitStruct.MCUInit.MCU_Clock = RCC_MCUSSOURCE_HSI; RCC_ClkInitStruct.MCUInit.MCU_Div = RCC_MCU_DIV1; RCC_ClkInitStruct.APB4_Div = RCC_APB4_DIV1; RCC_ClkInitStruct.APB5_Div = RCC_APB5_DIV1; RCC_ClkInitStruct.APB1_Div = RCC_APB1_DIV1; RCC_ClkInitStruct.APB2_Div = RCC_APB2_DIV1; RCC_ClkInitStruct.APB3_Div = RCC_APB3_DIV1;   if (HAL_RCC_ClockConfig(&RCC_ClkInitStruct) != HAL_OK) { Error_Handler(); } }   /** * @brief IPCC Initialization Function * @param None * @retval None */ static void MX_IPCC_Init(void) {   /* USER CODE BEGIN IPCC_Init 0 */   /* USER CODE END IPCC_Init 0 */   /* USER CODE BEGIN IPCC_Init 1 */   /* USER CODE END IPCC_Init 1 */ hipcc.Instance = IPCC; if (HAL_IPCC_Init(&hipcc) != HAL_OK) { Error_Handler(); } /* USER CODE BEGIN IPCC_Init 2 */   /* USER CODE END IPCC_Init 2 */   }   /** * @brief UART5 Initialization Function * @param None * @retval None */ static void MX_UART5_Init(void) {   /* USER CODE BEGIN UART5_Init 0 */   /* USER CODE END UART5_Init 0 */   /* USER CODE BEGIN UART5_Init 1 */   /* USER CODE END UART5_Init 1 */ huart5.Instance = UART5; huart5.Init.BaudRate = 115200; huart5.Init.WordLength = UART_WORDLENGTH_8B; huart5.Init.StopBits = UART_STOPBITS_1; huart5.Init.Parity = UART_PARITY_NONE; huart5.Init.Mode = UART_MODE_TX_RX; huart5.Init.HwFlowCtl = UART_HWCONTROL_NONE; huart5.Init.OverSampling = UART_OVERSAMPLING_16; huart5.Init.OneBitSampling = UART_ONE_BIT_SAMPLE_DISABLE; huart5.Init.ClockPrescaler = UART_PRESCALER_DIV1; huart5.AdvancedInit.AdvFeatureInit = UART_ADVFEATURE_NO_INIT; if (HAL_UART_Init(&huart5) != HAL_OK) { Error_Handler(); } if (HAL_UARTEx_SetTxFifoThreshold(&huart5, UART_TXFIFO_THRESHOLD_1_8) != HAL_OK) { Error_Handler(); } if (HAL_UARTEx_SetRxFifoThreshold(&huart5, UART_RXFIFO_THRESHOLD_1_8) != HAL_OK) { Error_Handler(); } if (HAL_UARTEx_DisableFifoMode(&huart5) != HAL_OK) { Error_Handler(); } /* USER CODE BEGIN UART5_Init 2 */   /* USER CODE END UART5_Init 2 */   }   /** * @brief GPIO Initialization Function * @param None * @retval None */ static void MX_GPIO_Init(void) {   /* GPIO Ports Clock Enable */ __HAL_RCC_GPIOB_CLK_ENABLE();   }   /* USER CODE BEGIN 4 */ static int rx_callback(struct rpmsg_endpoint *rp_chnl, void *data, size_t len, uint32_t src, void *priv) { /* copy received msg, and raise a flag */ memcpy(received_rpmsg, data, len > sizeof(received_rpmsg) ? sizeof(received_rpmsg) : len); printf("received_rpmsg=%s\r\n", received_rpmsg); rx_status = SET; return 0; } /* USER CODE END 4 */   /** * @brief This function is executed in case of error occurrence. * @retval None */ void Error_Handler(void) { /* USER CODE BEGIN Error_Handler_Debug */ /* User can add his own implementation to report the HAL error return state */   /* USER CODE END Error_Handler_Debug */ }   #ifdef USE_FULL_ASSERT /** * @brief Reports the name of the source file and the source line number * where the assert_param error has occurred. * @param file: pointer to the source file name * @param line: assert_param error line source number * @retval None */ void assert_failed(uint8_t *file, uint32_t line) { /* USER CODE BEGIN 6 */ /* User can add his own implementation to report the file name and line number, tex: printf("Wrong parameters value: file %s on line %d\r\n", file, line) */ /* USER CODE END 6 */ } #endif /* USE_FULL_ASSERT */   /************************ (C) COPYRIGHT STMicroelectronics *****END OF FILE****/

3.2.4 測試效果

首先加載驅動rpmsg_client_sample.ko，並修改打印等級。

1 2	insmod rpmsg_client_sample.ko echo 8 > /proc/sys/kernel/printk

 

然后加載M4固件，可以看到A7和M4都同時發送和接收到相互之間的數據。

1 2 3

cd /sys/class/remoteproc/remoteproc0 echo rpmsg_kernel_CM4.elf > firmware echo start > state

 

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