RT-Thread内核说明

2019-07-19 本文已影响0人 Mr_Michael

一、系统初始化

1. RT-Thread 的启动流程

（1）初始化与系统相关的硬件；

（2）初始化系统内核对象，例如定时器、调度器、信号；

（3）创建main线程，在main线程中对各类模块依次进行初始化；

（4）初始化定时器线程、空闲线程，并启动调度器。

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2. 组件初始化

RT-Thread 提供一种低耦合高内聚的初始化方式，不需要我们手动添加调用初始化函数，它能在系统运行前自动完成各模块的初始化。
组件初始化方式要求初始化函数主动通过一些宏接口进行申明，链接器会自动收集所有被申明的初始化函数，放到特定的数据段中，数据段中的所有函数在系统初始化时会被调用。
组件初始化的所有宏接口及其被初始化的顺序如下表所示
- INIT_BOARD_EXPORT(fn)声明的函数会被rt_components_board_init()调用，其他宏声明的函数会被rt_components_init()调用。

初始化顺序	接口	描述
1	INIT_BOARD_EXPORT(fn)	硬件的初始化，此时调度器还未启动
2	INIT_PREV_EXPORT(fn)	主要是用于纯软件的初始化、没有太多依赖的函数
3	INIT_DEVICE_EXPORT(fn)	外设驱动初始化相关，比如网卡设备
4	INIT_COMPONENT_EXPORT(fn)	组件初始化，比如文件系统或者LWIP
5	INIT_ENV_EXPORT(fn)	系统环境初始化，比如挂载文件系统
6	INIT_APP_EXPORT(fn)	应用初始化，比如GUI应用

3. 内核对象信息

系统所有的对象的信息都可以通过rt_object_get_information函数获取，RT-Thread所有的对象如下

RT_Object_Class_Thread	线程对象
RT_Object_Class_Semaphore	信号量对象
RT_Object_Class_Mutex	互斥量对象
RT_Object_Class_Event	事件对象
RT_Object_Class_MailBox	邮箱对象
RT_Object_Class_MessageQueue	消息队列对象
RT_Object_Class_MemHeap	内存堆对象
RT_Object_Class_MemPool	内存池对象
RT_Object_Class_Device	设备对象
RT_Object_Class_Timer	定时器对象
RT_Object_Class_Module	动态模块对象
RT_Object_Class_Unknown	未知对象
RT_Object_Class_Static	静态对象

查找所有在运行的线程

long list_thread(void)
{
    struct rt_object_information *info;

    info = rt_object_get_information(RT_Object_Class_Thread);
    return _list_thread(&info->object_list);
}
FINSH_FUNCTION_EXPORT(list_thread, list thread);
MSH_CMD_EXPORT(list_thread, list thread);

查找所有运行的动态模块

int list_module(void)
{
    struct rt_dlmodule *module;
    struct rt_list_node *list, *node;
    struct rt_object_information *info;

    info = rt_object_get_information(RT_Object_Class_Module);
    list = &info->object_list;

    rt_kprintf("module   ref      address \n");
    rt_kprintf("-------- -------- ------------\n");
    for (node = list->next; node != list; node = node->next)
    {
        module = (struct rt_dlmodule *)(rt_list_entry(node, struct rt_object, list));
        rt_kprintf("%-*.*s %-04d  0x%08x\n",
                   RT_NAME_MAX, RT_NAME_MAX, module->parent.name, module->nref, module->mem_space);
    }

    return 0;
}
MSH_CMD_EXPORT(list_module, list modules in system);

二、bsp工程资源的选择与配置

在bsp工程（如rt-thread\bsp\stm32\stm32f429-atk-apollo），通过menuconfig看到的配置选项，是通过bsp工程路径下个文件夹的Kconfig文件决定的。

stm32f429-atk-apollo\Kconfig文件

mainmenu "RT-Thread Configuration"

config BSP_DIR
    string
    option env="BSP_ROOT"
    default "."

config RTT_DIR
    string
    option env="RTT_ROOT"
    default "../../.."

config PKGS_DIR
    string
    option env="PKGS_ROOT"
    default "packages"
 
source "$RTT_DIR/Kconfig"
source "$PKGS_DIR/Kconfig"
source "../libraries/Kconfig"
source "board/Kconfig"

rt-thread\Kconfig文件

source "$RTT_DIR/src/Kconfig"
source "$RTT_DIR/libcpu/Kconfig"
source "$RTT_DIR/components/Kconfig"

及其路径所示各级文件

stm32f429-atk-apollo\board\Kconfig文件

menu "Hardware Drivers Config"

config SOC_STM32F429IG
    bool
    select SOC_SERIES_STM32F4
    default y

menu "Onboard Peripheral Drivers"

    config BSP_USING_USB_TO_USART
        bool "Enable USB TO USART (uart1)"
        select BSP_USING_UART
        select BSP_USING_UART1
        default y

    config BSP_USING_COM2
        bool "Enable COM2 (uart2 pin conflict with Ethernet and PWM)"
    select BSP_USING_UART
        select BSP_USING_UART2
        default n

    config BSP_USING_COM3
        bool "Enable COM3 (uart3 pin conflict with Ethernet)"
        select BSP_USING_UART3
        default n

    config BSP_USING_SDRAM
        bool "Enable SDRAM"
        select BSP_USING_FMC
        default n

    config BSP_USING_SPI_FLASH
        bool "Enable SPI FLASH (W25Q256 spi5)"
        select BSP_USING_SPI
        select BSP_USING_SPI5
        select RT_USING_SFUD
        select RT_SFUD_USING_SFDP
        default n

    config BSP_USING_MPU9250
        bool "Enable MPU 9250 (i2c1)"
        select BSP_USING_I2C1
        select PKG_USING_MPU6XXX
        default n

    config PHY_USING_LAN8720A
        bool

    config BSP_USING_ETH
        bool "Enable Ethernet"
        select BSP_USING_I2C1
        select PKG_USING_PCF8574
        select RT_USING_LWIP
        select PHY_USING_LAN8720A
        default n

    config BSP_USING_SDCARD
        bool "Enable SDCARD (sdio)"
        select BSP_USING_SDIO
        select RT_USING_DFS
        select RT_USING_DFS_ELMFAT
        default n

endmenu

menu "On-chip Peripheral Drivers"

    config BSP_USING_GPIO
        bool "Enable GPIO"
        select RT_USING_PIN
        default y

    menuconfig BSP_USING_UART
        bool "Enable UART"
        default y
        select RT_USING_SERIAL
        if BSP_USING_UART
            config BSP_USING_UART1
                bool "Enable UART1"
                default y

            config BSP_UART1_RX_USING_DMA
                bool "Enable UART1 RX DMA"
                depends on BSP_USING_UART1 && RT_SERIAL_USING_DMA
                default n

            config BSP_USING_UART2
                bool "Enable UART2"
                default n

            config BSP_UART2_RX_USING_DMA
                bool "Enable UART2 RX DMA"
                depends on BSP_USING_UART2 && RT_SERIAL_USING_DMA
                default n
                
            config BSP_USING_UART3
                bool "Enable UART3"
                default n
   
            config BSP_UART3_RX_USING_DMA
                bool "Enable UART3 RX DMA"
                depends on BSP_USING_UART3 && RT_SERIAL_USING_DMA
                default n  
        endif

    config BSP_USING_ON_CHIP_FLASH
        bool "Enable on-chip FLASH"
        default n

    menuconfig BSP_USING_SPI
        bool "Enable SPI BUS"
        default n
        select RT_USING_SPI
        if BSP_USING_SPI
            config BSP_USING_SPI1
                bool "Enable SPI1 BUS"
                default n

            config BSP_SPI1_TX_USING_DMA
                bool "Enable SPI1 TX DMA"
                depends on BSP_USING_SPI1
                default n
                
            config BSP_SPI1_RX_USING_DMA
                bool "Enable SPI1 RX DMA"
                depends on BSP_USING_SPI1
                select BSP_SPI1_TX_USING_DMA
                default n

            config BSP_USING_SPI2
                bool "Enable SPI2 BUS"
                default n  
                
            config BSP_SPI2_TX_USING_DMA
                bool "Enable SPI2 TX DMA"
                depends on BSP_USING_SPI2
                default n
                
            config BSP_SPI2_RX_USING_DMA
                bool "Enable SPI2 RX DMA"
                depends on BSP_USING_SPI2
                select BSP_SPI2_TX_USING_DMA
                default n
                
            config BSP_USING_SPI5
                bool "Enable SPI5 BUS"
                default n        

            config BSP_SPI5_TX_USING_DMA
                bool "Enable SPI5 TX DMA"
                depends on BSP_USING_SPI5
                default n
                
            config BSP_SPI5_RX_USING_DMA
                bool "Enable SPI5 RX DMA"
                depends on BSP_USING_SPI5
                select BSP_SPI5_TX_USING_DMA
                default n  
        endif

    menuconfig BSP_USING_I2C1
        bool "Enable I2C1 BUS (software simulation)"
        default n
        select RT_USING_I2C
        select RT_USING_I2C_BITOPS
        select RT_USING_PIN
        if BSP_USING_I2C1
            comment "Notice: PH4 --> 116; PH5 --> 117"
            config BSP_I2C1_SCL_PIN
                int "I2C1 scl pin number"
                range 1 176
                default 116
            config BSP_I2C1_SDA_PIN
                int "I2C1 sda pin number"
                range 1 176
                default 117
        endif

    menuconfig BSP_USING_TIM
        bool "Enable timer"
        default n
        select RT_USING_HWTIMER
        if BSP_USING_TIM
            config BSP_USING_TIM11
                bool "Enable TIM11"
                default n

            config BSP_USING_TIM13
                bool "Enable TIM13"
                default n

            config BSP_USING_TIM14
                bool "Enable TIM14"
                default n
        endif

    menuconfig BSP_USING_PWM
        bool "Enable pwm"
        default n
        select RT_USING_PWM
        if BSP_USING_PWM
        menuconfig BSP_USING_PWM2
            bool "Enable timer2 output pwm"
            default n
            if BSP_USING_PWM2
                config BSP_USING_PWM2_CH4
                    bool "Enable PWM2 channel4"
                    default n
            endif
        endif

    menuconfig BSP_USING_ADC
        bool "Enable ADC"
        default n
        select RT_USING_ADC
        if BSP_USING_ADC
            config BSP_USING_ADC1
                bool "Enable ADC1"
                default n
        endif

    menuconfig BSP_USING_ONCHIP_RTC
        bool "Enable RTC"
        select RT_USING_RTC
        select RT_USING_LIBC
        default n
        if BSP_USING_ONCHIP_RTC
            choice
                prompt "Select clock source"
                default BSP_RTC_USING_LSE

                config BSP_RTC_USING_LSE
                    bool "RTC USING LSE"

                config BSP_RTC_USING_LSI
                    bool "RTC USING LSI"
            endchoice
        endif

    config BSP_USING_WDT
        bool "Enable Watchdog Timer"
        select RT_USING_WDT
        default n

    config BSP_USING_SDIO
        bool "Enable SDIO"
        select RT_USING_SDIO
        select RT_USING_DFS
        default n

    config BSP_USING_FMC
        bool
        default n
endmenu

menu "Board extended module Drivers"

endmenu

endmenu

Kconfig是类似lua语言的配置方式，menuconfig保存配置时会将所有config为ture的选项添加到rtconfig.h的文件的宏定义。
工程根据宏定义进行选择编译的内容。