RT-Thread-自动初始化结构简介-RT-Thread问答社区

自动初始化结构简介-

发布于 2022-06-14 10:09:15 浏览：636 订阅该版

[tocm]

环境：rt-thread 4.0.3  rt-thread studio 2.2.1  ART-Pi

### 定义 函数指针块
主要用于map文件标记
**components.c** 中
```c
static int rti_start(void)

return 0;
}
INIT_EXPORT(rti_start, "0");

static int rti_board_start(void)
{
    return 0;
}
INIT_EXPORT(rti_board_start, "0.end");

static int rti_board_end(void)

return 0;
}
INIT_EXPORT(rti_board_end, "1.end");

static int rti_end(void)
{
    return 0;
}
INIT_EXPORT(rti_end, "6.end");
```

### 执行
- void rt_components_board_init(void)  执行第0等级 
- void rt_components_init(void) 执行其余等级
**rtthread.map**
```c
 *(SORT(.rti_fn*))
 .rti_fn.0      0x9002a5fc        0x4 ./rt-thread/src/components.o
                0x9002a5fc                __rt_init_rti_start
 .rti_fn.0.end  0x9002a600        0x4 ./rt-thread/src/components.o
                0x9002a600                __rt_init_rti_board_start
 .rti_fn.1      0x9002a604        0x4 ./libraries/drivers/drv_adc.o
                0x9002a604                __rt_init_stm32_adc_init
 .rti_fn.1      0x9002a608        0x4 ./board/board.o
                0x9002a608                __rt_init_clock_information
 .rti_fn.1      0x9002a60c        0x4 ./board/drv_mpu.o
                0x9002a60c                __rt_init_mpu_init
 .rti_fn.1      0x9002a610        0x4 ./applications/main.o
                0x9002a610                __rt_init_vtor_config
 .rti_fn.1.end  0x9002a614        0x4 ./rt-thread/src/components.o
                0x9002a614                __rt_init_rti_board_end
 .rti_fn.2      0x9002a618        0x4 ./rt-thread/components/utilities/ulog/backend/console_be.o
                0x9002a618                __rt_init_ulog_console_backend_init
 .rti_fn.2      0x9002a61c        0x4 ./rt-thread/components/utilities/ulog/ulog.o
                0x9002a61c                __rt_init_ulog_init
 .rti_fn.2      0x9002a620        0x4 ./rt-thread/components/dfs/src/dfs.o
                0x9002a620                __rt_init_dfs_init
 .rti_fn.4      0x9002a624        0x4 ./rt-thread/components/utilities/utest/utest.o
                0x9002a624                __rt_init_utest_init
 .rti_fn.4      0x9002a628        0x4 ./rt-thread/components/libc/compilers/newlib/libc.o
                0x9002a628                __rt_init_libc_system_init
 .rti_fn.5      0x9002a62c        0x4 ./applications/uart_sample.o
                0x9002a62c                __rt_init_uart_dma_sample
 .rti_fn.6      0x9002a630        0x4 ./rt-thread/components/finsh/shell.o
                0x9002a630                __rt_init_finsh_system_init
 .rti_fn.6.end  0x9002a634        0x4 ./rt-thread/src/components.o
                0x9002a634                __rt_init_rti_end
                0x9002a638                __rt_init_end = .
                0x9002a638                . = ALIGN (0x4)
                [!provide]                PROVIDE (__ctors_start__, .)
```
### 怎样插入函数指针

**rtdef.h**  中
宏定义

```c
/* board init routines will be called in board_init() function */
#define INIT_BOARD_EXPORT(fn)           INIT_EXPORT(fn, "1")

/* pre/device/component/env/app init routines will be called in init_thread */
/* components pre-initialization (pure software initilization) */
#define INIT_PREV_EXPORT(fn)            INIT_EXPORT(fn, "2")
/* device initialization */
#define INIT_DEVICE_EXPORT(fn)          INIT_EXPORT(fn, "3")
/* components initialization (dfs, lwip, ...) */
#define INIT_COMPONENT_EXPORT(fn)       INIT_EXPORT(fn, "4")
/* environment initialization (mount disk, ...) */
#define INIT_ENV_EXPORT(fn)             INIT_EXPORT(fn, "5")
/* appliation initialization (rtgui application etc ...) */
#define INIT_APP_EXPORT(fn)             INIT_EXPORT(fn, "6")
```

```c
    #define SECTION(x)                  __attribute__((section(x)))
    #define RT_UNUSED                   __attribute__((unused))
    #define RT_USED                     __attribute__((used))
    #define ALIGN(n)                    __attribute__((aligned(n)))
    #define RT_WEAK                     __attribute__((weak))
    #define rt_inline                   static __inline
```

```c
typedef int (*init_fn_t)(void);
```

```c
RT_USED const init_fn_t __rt_init_##fn SECTION(".rti_fn." level) = fn
```
- 编译保留        `RT_USED      `
- 函数指针        `init_fn_t`
- 函数名--宏连接          `__rt_init_##fn                      `
- 编译位置        `SECTION(".rti_fn." level)`