10 dfs_ramfs如何挂载

发布于 2021-10-28 11:33:27 浏览：1231 订阅该版

硬件环境：STM407ZET6 + FM25V02A（铁电存储器）

代码如下
```c
struct rt_device_ops fram_ops = {
    .read = _fram_read,
    .write = _fram_write};
static struct rt_device fram_dev;
static int _fram_dev_register(void)
{
    fram_dev.type = RT_Device_Class_Block;
    fram_dev.ops = &fram_ops;
    return rt_device_register(&fram_dev, "fram", RT_DEVICE_FLAG_RDWR | RT_DEVICE_FLAG_STANDALONE);
}

static int rt_hw_spi_flash_init(void)
{
    struct rt_spi_device *fram = RT_NULL;
    __HAL_RCC_GPIOB_CLK_ENABLE();

rt_pin_mode(FRAM_CS, PIN_MODE_OUTPUT);

rt_hw_spi_device_attach("spi2", "spi2fram", GPIOB, GPIO_PIN_12);

fram = (struct rt_spi_device *)rt_device_find("spi2fram");
 
    fram->config.data_width = 8;
    fram->config.mode = SPI_MODE_MASTER | RT_SPI_MSB | RT_SPI_MODE_3;
    fram->config.max_hz = 80 * 1000 * 1000;

return _fram_dev_register();
}
/* 导出到自动初始化 */
INIT_COMPONENT_EXPORT(rt_hw_spi_flash_init);

ALIGN(RT_ALIGN_SIZE)
static rt_uint8_t ramfs_class[256 + sizeof(struct dfs_ramfs)] = {0};
static int fram_mount(void)
{
    dfs_ramfs_create(ramfs_class, 256 + sizeof(struct dfs_ramfs));
    return dfs_mount("fram", "/", "ram", 0, ramfs_class);
}
INIT_ENV_EXPORT(fram_mount);
```

铁电走的spi协议，并且成功注册为spi总线设备，
之后然后我又将其手动注册了一个块设备。并挂载成功
```c
static int fram_mount(void)
{
    dfs_ramfs_create(ramfs_class, 256 + sizeof(struct dfs_ramfs));
    return dfs_mount("fram", "/", "ram", 0, ramfs_class);
}
INIT_ENV_EXPORT(fram_mount);
```

控制台操作如下：
```
 \ | /
- RT -     Thread Operating System
 / | \     4.0.4 build Oct 28 2021 09:05:57
 2006 - 2021 Copyright by rt-thread team
do components initialization.
initialize rti_board_end:0 done
initialize dfs_init:0 done
initialize ulog_console_backend_init:0 done
initialize rt_hw_spi_flash_init:0 done
initialize dfs_ramfs_init:0 done
initialize fram_mount:0 done
initialize finsh_system_init:0 done
msh />
msh />
msh />ls
Directory /:
msh />cd
/
msh />ls
Directory /:
msh />cd /
msh />cd /:
No such directory: /:
msh />cd /ram
No such directory: /ram
msh />cd /fram
No such directory: /fram
msh />cd /ramfs
No such directory: /ramfs
msh />cd /dev
msh /dev>
```
显示找不到 ram
 
问题请教：我这个ramfs 系统是挂载成功了吗？  
为什么不能像代开`/dev`一样
```
cd /ram   
cd/fram   
cd /ramfs
```