STM32之RT Thread

发表于 2021-08-25 更新于 2023-08-22 分类于编程开发，开发工具

RTOS在嵌入式开发大行其道，RT-Thread有很丰富的外设驱动，遂折腾以下RT-Thread(本文的RT-Thread均指RT-Thread Nano)。

环境： Win10x64, STM32CubeIDE v1.7.0
开发板： DevEBox STM32F407VE

1、`STM32F407VE`开发板基本参数。

(1) Specifications

STM32F407VET6 ARM Cortex M4
168MHz, 210 DMIPS / 1.25 DMIPS / MHz
1.8V - 3.6V operating voltage
8MHz system crystal
32.768KHz RTC crystal
2.54mm pitch pins
SWD header
512 KByte Flash, 192 + 4 KByte SRAM
3x SPI, 3x USART, 2x UART, 2x I2S, 3x I2C
1x FSMC, 1x SDIO, 2x CAN
1x USB 2.0 FS / HS controller (with dedicated DMA)
1x USB HS ULPI (for external USB HS PHY)
Micro SD
Winbond W25Q16 16Mbit SPI Flash
1x 10/100 Ethernet MAC
1x 8 to 12-bit Parallel Camera interface
3x ADC (12-bit / 16-channel)
2x DAC (12-bit)
12x general timers, 2x advanced timers
AMS1117-3.3V: 3.3V LDO voltage regulator, max current 800mA
Micro USB for power and comms
Power LED D1
User LED D2 (PA1) active low
Reset button, 1x user buttons K0
2x22 side header
SPI TFT/OLED header (3V3, GND, MOSI, SCK, CS, MISO, RST, BL)
RTC battery header B1 beside SD card
M3 mounting holes
Dimensions: 40.89mm x 68.59mm

(2) Exposed Port Pins

PA0-PA15
PB0-PB3, PB5-PB15 (PB4 SPI1_MISO used exclusively with SPI Flash)
PC0-PC13 (PC14 OSC32_IN and PC15 OSC32_OUT not broken out)
PD0-PD15
PE0-PE15

(3) Peripherals

TFT/OLED (J4)

index	Pin	Usage	index	Pin	Usage
1	-	3V3	5	PB12	CS
2	-	GND	6	PB14	MISO
3	PB15	MOSI	7	PC5	RS
4	PB13	SCK	8	PB1	BLK

SPI Flash W25Q16 (U3)

index	Pin	Usage	index	Pin	Usage
1	PA15	F_CS	5	PB5	SPI1_MOSI
2	PB4	SPI1_MISO	6	PB3	SPI1_SCK
3	WP	3V3	7	HOLD	3V3
4	-	GND	8	VCC	3V3

SWD debug (J1)

index	Pin	Usage	index	Pin	Usage
1		Boot0	4	PA13	SWDIO
2	-	3V3	5	PA14	SWCLK
3	-	GND

USB (J5)

index	Pin	Usage	index	Pin	Usage
1	VCC	5V	4	NC	ID
2	PA11	USB_DM	5	-	GND
3	PA12	USB_DP

Micro SD (U5)

index	Pin	Usage	index	Pin	Usage
1	PC10	SDIO_D2	6	-	GND
2	PC11	SDIO_D3	7	PC8	SDIO_D0
3	PD2	SDIO_CMD	8	PC9	SDIO_D1
4	-	3V3	9	NC	SD_NC
5	PC12	SDIO_SCK

User Button (K1)

index	Pin	Usage	index	Pin	Usage
1	PA0	WK_UP

User LED (D2)

index	Pin	Usage	index	Pin	Usage
1	PA1	User LED

Battery (B1)

index	Pin	Usage	index	Pin	Usage
1	-	BAT54C	2	-	GND

2、工程创建与修改

使用STM32CubeIDE(以下简称CubeIde)创建工程的过程非常程序化，选芯片->配置外设->配置时钟->配置所用的库，具体过程网上很多，此处略过。以下核心记录RT-Thread的使用方法。

(1) 安装并在工程中导入`RT-Thread Nano`包，

基本过程请参考RT-Thread 文档。重点是在CubeIde中通过连接https://www.rt-thread.org/download/cube/RealThread.RT-Thread.pdsc安装，并在工程中配置。

(2) `CubeIde`中配置`RT-Thread Nano`需要注意的几个问题

如文档所述， RT-Thread重定义HardFault_Handler、PendSV_Handler、SysTick_Handler 中断函数，为了避免重复定义的问题，需要在NVIC->Code generate中禁止生成Hard fault interrupt, Pendable request, Time base :System tick timer三个函数。实际操作中，如果选择了定时器作为时基，那么只需要禁止生成Hard fault interrupt即可。
启用RT_USING_HEAP、RT_USING_DEVICE和finsh。前两个直接在CubeIde点选即可，最后一个需要打开rtconfig.h编辑。

// <h>Enable FinSH Configuration
// <c1>include shell config
//  <i> Select this choice if you using FinSH
#include "finsh_config.h"
// </c>
// </h>

编译器参数修改，Project->properties->C/C++ Build->Settings->Tool Settings，在MCU GCC Assembler->Miscellaneous添加-Wa,-mimplicit-it=thumb。MCU GCC Compiler->Include paths添加相应的头文件(如果没有，貌似nano 3.1.5已经自动添加了5个相关头文件路径)
修改启动文件Core/Startup/startup_stm32f407vetx.s，第100行bl main => bl entry。（注第98行bl __libc_init_array在RT-Thread Studio自带的代码中，是注释的，不过此处保留后，尚未遇到问题）

修改STM32F407VETX_FLASH.ld文件，开启自动初始化，并使finsh正常工作。


  . = ALIGN(4);
  _etext = .;        /* define a global symbols at end of code */
  /**************添加以下内容*************/
  /* section information for finsh shell */
   . = ALIGN(4);
   __fsymtab_start = .;
   KEEP(*(FSymTab))
   __fsymtab_end = .;
   . = ALIGN(4);
   __vsymtab_start = .;
   KEEP(*(VSymTab))
   __vsymtab_end = .;
   . = ALIGN(4);
   
   /* section information for initial. */
   . = ALIGN(4);
   __rt_init_start = .;
   KEEP(*(SORT(.rti_fn*)))
   __rt_init_end = .;
   . = ALIGN(4);
  /**************添加内容结束*************/     
} >FLASH

1、STM32F407VE开发板基本参数。