FAL使用片内flash挂载dfs失败是何原因呢？

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RT - Thread Operating System
/ | \ 4.0.2 build Feb 21 2021
2006 - 2019 Copyright by rt-thread team
[D/FAL] (fal_flash_init:63) Flash device | stm32_onchip | addr: 0x08000000 | len: 0x00080000 | blk_size: 0x00000800 |initialized finish.
[I/FAL] ==================== FAL partition table ====================
[I/FAL] | name | flash_dev | offset | length |
[I/FAL] -------------------------------------------------------------
[I/FAL] | app | stm32_onchip | 0x00000000 | 0x00078000 |
[I/FAL] | dfs | stm32_onchip | 0x00078000 | 0x00008000 |
[I/FAL] =============================================================
[I/FAL] RT-Thread Flash Abstraction Layer (V0.5.0) initialize success.
[I/FAL] The FAL block device (dfs) created successfully
format error
dfs mount failed!
#include <rtthread.h>
#include <rtdevice.h>
#include <drv_common.h>
#include "dfs_fs.h"
extern "C" {
#include <fal.h>
}
#define DFS_PARITION_NAME "dfs"
static struct rt_device *flash_dev = NULL;
static int mnt_flash()
{
fal_init();
flash_dev = fal_blk_device_create(DFS_PARITION_NAME);
return RT_EOK;
}
INIT_COMPONENT_EXPORT(mnt_flash);
static int mnt_dfs()
{
dfs_mkfs("elm", flash_dev->parent.name);
if (dfs_mount(flash_dev->parent.name, "/", "elm", 0, 0) == 0)
{
rt_kprintf("dfs mount successful!\n");
}
else
{
rt_kprintf("dfs mount failed!\n");
}
return RT_EOK;
}
INIT_APP_EXPORT(mnt_dfs);

各位老师帮我看看是哪里没有弄对，谢谢！