FAL組件和DFS文件系統(tǒng)的功能特點(diǎn)和使用方法

FAL組件
什么是FAL?

FAL (Flash Abstraction Layer)Flash 抽象層，是對(duì) Flash 及基于 Flash 的分區(qū)進(jìn)行管理、操作的抽象層，對(duì)上層統(tǒng)一了 Flash 及 分區(qū)操作的 API (框架圖如下所示)，并具有以下特性：

支持靜態(tài)可配置的分區(qū)表，并可關(guān)聯(lián)多個(gè) Flash 設(shè)備；

分區(qū)表支持自動(dòng)裝載。避免在多固件項(xiàng)目，分區(qū)表被多次定義的問題；

代碼精簡，對(duì)操作系統(tǒng)無依賴，可運(yùn)行于裸機(jī)平臺(tái)，比如對(duì)資源有一定要求的 Bootloader；

統(tǒng)一的操作接口。保證了文件系統(tǒng)、OTA、NVM（例如：EasyFlash） 等對(duì) Flash 有一定依賴的組件，底層 Flash 驅(qū)動(dòng)的可重用性；

自帶基于 Finsh/MSH 的測試命令，可以通過 Shell 按字節(jié)尋址的方式操作（讀寫擦） Flash 或分區(qū)，方便開發(fā)者進(jìn)行調(diào)試、測試；

通過上圖可以清晰明了看到，F(xiàn)AL抽象層向下可以通過Flash硬件進(jìn)行統(tǒng)一管理，當(dāng)然也可以使用SFUD框架（串行Flash通用驅(qū)動(dòng)庫，這部分RT-Thread官方已完成框架的移植同時(shí)提供多個(gè)應(yīng)用歷程），而對(duì)上也可以使用如DFS、NVM提供的Flash硬件統(tǒng)一訪問接口，方便用戶更加直接方便對(duì)底層flash硬件的訪問操作。 注：非易失性存儲(chǔ)器 (NVM)：在芯片電源關(guān)閉期間保存存儲(chǔ)在其中的數(shù)據(jù)。因此，它被用于沒有磁盤的便攜式設(shè)備中的內(nèi)存，以及用于可移動(dòng)存儲(chǔ)卡等用途。主要類型有：非易失性半導(dǎo)體存儲(chǔ)器 (Non-volatile semiconductor memory, NVSM) 將數(shù)據(jù)存儲(chǔ)在浮柵存儲(chǔ)單元中，每個(gè)單元都由一個(gè)浮柵(floating-gate) MOSFET 組成。

關(guān)于存儲(chǔ)，可以用一張圖來解釋：

FAL組件使用ENV配置FAL

在RT-Thread v4.1.0之前，F(xiàn)AL是作為軟件包形式對(duì)用戶開放使用的，而v4.1.0之后，F(xiàn)AL被RT-Thread官方重新定義為RTT組件的一部分，這樣也能更加方便用戶的開發(fā)。

下面正式講解FAL組件的使用：

首先打開ENV工具，根據(jù)以下路徑打開FAL使能RT-Thread Components->FAL: flash abstraction layer，由于后面會(huì)用到SFUD，所以這里把FAL uses SFUD drivers一并使能，并修改FAL設(shè)備名稱為W25Q128.

完成上述操作后保存退出，并使用scons --target=mdk5重新生成MDK5文件并打開。

FAL組件FAL SFUD移植

示例選用W25Q128 spi flash作為測試模塊，并且使用SFUD框架對(duì)spi flash設(shè)備進(jìn)行管理和驅(qū)動(dòng)。 由于目前RT-Thread的SFUD已經(jīng)對(duì)W25Q128完成支持，根據(jù)官方的使用手冊(cè)，僅需編寫fal_cfg.h文件完成對(duì)FAL_FLASH_DEV_TABLE及FAL_PART_TABLE的定義即可。文件存放路徑：. t-threadsplpc55sxxlpc55s69_nxp_evkoardportsfal_cfg.h

// fal.cfg.h
/*
  * Copyright (c) 2006-2023, RT-Thread Development Team
  *
  * SPDX-License-Identifier: Apache-2.0
  *
  * Change Logs:
  * Date           Author       Notes
  * 2023-04-21     Wangyuqiang  the first version
  */
#ifndef _FAL_CFG_H_
#define _FAL_CFG_H_


#include 
#include 


#ifndef FAL_USING_NOR_FLASH_DEV_NAME
#define NOR_FLASH_DEV_NAME             "norflash0"
#else
#define NOR_FLASH_DEV_NAME              FAL_USING_NOR_FLASH_DEV_NAME
#endif


/* Flash device Configuration */


extern struct fal_flash_dev nor_flash0;


/* flash device table */


#define FAL_FLASH_DEV_TABLE                                          
{                                                                    
     &nor_flash0,                                                     
}


/* Partition Configuration */


#ifdef FAL_PART_HAS_TABLE_CFG


/* partition table */


#define FAL_PART_TABLE                                                                                                  
{                                                                                                                       
     {FAL_PART_MAGIC_WROD,  "easyflash", NOR_FLASH_DEV_NAME,                                    0,       512 * 1024, 0}, 
     {FAL_PART_MAGIC_WROD,   "download", NOR_FLASH_DEV_NAME,                           512 * 1024,      1024 * 1024, 0}, 
     {FAL_PART_MAGIC_WROD, "wifi_image", NOR_FLASH_DEV_NAME,                  (512 + 1024) * 1024,       512 * 1024, 0}, 
     {FAL_PART_MAGIC_WROD,       "font", NOR_FLASH_DEV_NAME,            (512 + 1024 + 512) * 1024,  7 * 1024 * 1024, 0}, 
     {FAL_PART_MAGIC_WROD, "filesystem", NOR_FLASH_DEV_NAME, (512 + 1024 + 512 + 7 * 1024) * 1024,  7 * 1024 * 1024, 0}, 
}
#endif /* FAL_PART_HAS_TABLE_CFG */
#endif /* _FAL_CFG_H_ */

此時(shí)編譯的話是找不到該頭文件的，需要在Keil中設(shè)置：

在RTT FAL組件中的SFUD提供的fal_flash_dev對(duì)象默認(rèn)的nor_flash0參數(shù)中，flash大小默認(rèn)為8M，而W25Q128最大最16M,可以選擇在. t-threadcomponentsfalsamplesportingfal_flash_sfud_port.c文件中對(duì)struct fal_flash_dev nor_flash0進(jìn)行修改：

struct fal_flash_dev nor_flash0 =
{
     .name       = FAL_USING_NOR_FLASH_DEV_NAME,
     .addr       = 0,
     .len        = 16 * 1024 * 1024,
     .blk_size   = 4096,
     .ops        = {init, read, write, erase},
     .write_gran = 1
};

當(dāng)然也可以選擇不進(jìn)行修改，專家的原話是因?yàn)樵谡{(diào)用初始化接口函數(shù)init后，會(huì)從flash設(shè)備讀取正確的參數(shù)更新到nor_flash0表項(xiàng)中，在使用FAL組件前都需要調(diào)用FAL初始化函數(shù)fal_init，其內(nèi)調(diào)用flash設(shè)備初始化函數(shù)fal_flash_init，最后會(huì)調(diào)用注冊(cè)到fal_flash_dev設(shè)備表項(xiàng)中的初始化函數(shù)device_table->ops.init，所以nor_flash0表項(xiàng)參數(shù)會(huì)在FAL初始化時(shí)被更新。

同時(shí)需要開啟SFUD框架支持，打開ENV工具，由于SFUD的使用需要指定一個(gè)spi設(shè)備，這里我選擇使用最近移植好的軟件spi，路徑Hardware Drivers Config->On-chip Peripheral Drivers-> Enable soft SPI BUS->Enable soft SPI1 BUS (software simulation)，這里的測試開發(fā)板是恩智浦LPC55S69-EVK，并且這款BSP的軟件模擬SPI由我本人對(duì)接，關(guān)于這部分的軟件SPI引腳定義可以選用默認(rèn)即可，當(dāng)然也可以使用自定義引腳，只要不與其他引腳產(chǎn)生沖突。

此時(shí)回到ENV主界面，進(jìn)入RT-Thread Components->Device Drivers->Using Serial Flash Universal Driver，此時(shí)才可以看到SFUD選項(xiàng)出現(xiàn)（如果沒有使能SPI則無法看到），使能后保持默認(rèn)。

FAL組件FAL SFUD測試用例

為了驗(yàn)證W25Q128及軟件模擬SPI在SFUD框架上是否能夠成功運(yùn)行，在. t-threadsplpc55sxxlpc55s69_nxp_evkoardports下新建一個(gè)soft_spi_flash_init.c文件，代碼如下：

/*
  * Copyright (c) 2006-2023, RT-Thread Development Team
  *
  * SPDX-License-Identifier: Apache-2.0
  *
  * Change Logs:
  * Date           Author       Notes
  * 2023-04-21     Wangyuqiang  the first version
  */


#include 
#include "spi_flash.h"
#include "spi_flash_sfud.h"
#include "drv_soft_spi.h"
#include "drv_pin.h"
#include "rtconfig.h"


#define cs_pin  GET_PINS(1,9)


static int rt_soft_spi_flash_init(void)
{
int result = -1;


     result = rt_hw_softspi_device_attach("sspi1", "sspi10", cs_pin);
     rt_kprintf("value is %d
",result);


if(result == RT_EOK)
     {
         rt_kprintf("rt_hw_softspi_device_attach successful!
");
     }


if (RT_NULL == rt_sfud_flash_probe("W25Q128", "sspi10"))
     {
return -RT_ERROR;
     }


return RT_EOK;
}
INIT_COMPONENT_EXPORT(rt_soft_spi_flash_init);

這里需要指定一個(gè)片選引腳，這里暫時(shí)使用了SSPI2的SCK引腳作為片選，需要注意不要同時(shí)打開SSPI1和SSPI2，后續(xù)我會(huì)專門上傳一個(gè)通用GPIO作為片選引腳，避免產(chǎn)生問題。然后軟件SPI設(shè)備的掛載使用的是SSPI1 bus及SSPI10 device，并且掛載flash設(shè)備到SSPI10。

在 . t-threadsplpc55sxxlpc55s69_nxp_evkoardports 下新建fal_sample.c文件，并編寫測試代碼：

//fal_sample.c


/*
  * Copyright (c) 2006-2023, RT-Thread Development Team
  *
  * SPDX-License-Identifier: Apache-2.0
  *
  * Change Logs:
  * Date           Author       Notes
  * 2023-04-21     Wangyuqiang  the first version
  */


#include "rtthread.h"
#include "rtdevice.h"
#include "board.h"
#include "fal.h"


#define BUF_SIZE 1024


static int fal_test(const char *partiton_name)
{
int ret;
int i, j, len;
     uint8_t buf[BUF_SIZE];
const struct fal_flash_dev *flash_dev = RT_NULL;
const struct fal_partition *partition = RT_NULL;


if (!partiton_name)
     {
         rt_kprintf("Input param partition name is null!
");
return -1;
     }


     partition = fal_partition_find(partiton_name);
if (partition == RT_NULL)
     {
         rt_kprintf("Find partition (%s) failed!
", partiton_name);
         ret = -1;
return ret;
     }


     flash_dev = fal_flash_device_find(partition->flash_name);
if (flash_dev == RT_NULL)
     {
         rt_kprintf("Find flash device (%s) failed!
", partition->flash_name);
         ret = -1;
return ret;
     }


     rt_kprintf("Flash device : %s   "
"Flash size : %dK   
"
"Partition : %s   "
"Partition size: %dK
",
                 partition->flash_name,
                 flash_dev->len/1024,
                 partition->name,
                 partition->len/1024);


/* erase all partition */
     ret = fal_partition_erase_all(partition);
if (ret < 0)
     {
         rt_kprintf("Partition (%s) erase failed!
", partition->name);
         ret = -1;
return ret;
     }
     rt_kprintf("Erase (%s) partition finish!
", partiton_name);


/* read the specified partition and check data */
for (i = 0; i < partition->len;)
     {
         rt_memset(buf, 0x00, BUF_SIZE);


len = (partition->len - i) > BUF_SIZE ? BUF_SIZE : (partition->len - i);


         ret = fal_partition_read(partition, i, buf, len);
if (ret < 0)
         {
             rt_kprintf("Partition (%s) read failed!
", partition->name);
             ret = -1;
return ret;
         }


for(j = 0; j < len; j++)
         {
if (buf[j] != 0xFF)
             {
                 rt_kprintf("The erase operation did not really succeed!
");
                 ret = -1;
return ret;
             }
         }
         i += len;
     }


/* write 0x00 to the specified partition */
for (i = 0; i < partition->len;)
     {
         rt_memset(buf, 0x00, BUF_SIZE);


len = (partition->len - i) > BUF_SIZE ? BUF_SIZE : (partition->len - i);


         ret = fal_partition_write(partition, i, buf, len);
if (ret < 0)
         {
             rt_kprintf("Partition (%s) write failed!
", partition->name);
             ret = -1;
return ret;
         }


         i += len;
     }
     rt_kprintf("Write (%s) partition finish! Write size %d(%dK).
", partiton_name, i, i/1024);


/* read the specified partition and check data */
for (i = 0; i < partition->len;)
     {
         rt_memset(buf, 0xFF, BUF_SIZE);


len = (partition->len - i) > BUF_SIZE ? BUF_SIZE : (partition->len - i);


         ret = fal_partition_read(partition, i, buf, len);
if (ret < 0)
         {
             rt_kprintf("Partition (%s) read failed!
", partition->name);
             ret = -1;
return ret;
         }


for(j = 0; j < len; j++)
         {
if (buf[j] != 0x00)
             {
                 rt_kprintf("The write operation did not really succeed!
");
                 ret = -1;
return ret;
             }
         }


         i += len;
     }


     ret = 0;
return ret;
}


static void fal_sample(void)
{
/* 1- init */
     fal_init();


if (fal_test("font") == 0)
     {
         rt_kprintf("Fal partition (%s) test success!
", "font");
     }
else
     {
         rt_kprintf("Fal partition (%s) test failed!
", "font");
     }


if (fal_test("download") == 0)
     {
         rt_kprintf("Fal partition (%s) test success!
", "download");
     }
else
     {
         rt_kprintf("Fal partition (%s) test failed!
", "download");
     }
}
MSH_CMD_EXPORT(fal_sample, fal sample);

msh/>easyflash_sample

DFS文件系統(tǒng)什么是DFS?

DFS 是 RT-Thread 提供的虛擬文件系統(tǒng)組件，全稱為 Device File System，即設(shè)備虛擬文件系統(tǒng)，文件系統(tǒng)的名稱使用類似 UNIX 文件、文件夾的風(fēng)格，目錄結(jié)構(gòu)如下圖所示：

在 RT-Thread DFS 中，文件系統(tǒng)有統(tǒng)一的根目錄，使用 / 來表示。而在根目錄下的 f1.bin 文件則使用 /f1.bin 來表示，2018 目錄下的 f1.bin 目錄則使用 /data/2018/f1.bin 來表示。即目錄的分割符號(hào)是 /，這與 UNIX/Linux 完全相同，與 Windows 則不相同（Windows 操作系統(tǒng)上使用 來作為目錄的分割符）。

DFS文件系統(tǒng) DFS架構(gòu)

RT-Thread DFS 組件的主要功能特點(diǎn)有：

為應(yīng)用程序提供統(tǒng)一的 POSIX 文件和目錄操作接口：read、write、poll/select 等；

支持多種類型的文件系統(tǒng)，如 FatFS、RomFS、DevFS 等，并提供普通文件、設(shè)備文件、網(wǎng)絡(luò)文件描述符的管理；

支持多種類型的存儲(chǔ)設(shè)備，如 SD Card、SPI Flash、Nand Flash 等；

DFS 的層次架構(gòu)主要分為 POSIX 接口層、虛擬文件系統(tǒng)層和設(shè)備抽象層；

DFS文件系統(tǒng)使用ENV配置DFS

打開ENV, 進(jìn)入路徑RT-Thread Components → DFS: device virtual file system，使能DFS: device virtual file system

由于DFS使用的是POSIX接口，而dfs_posix.h已經(jīng)在新版本中移除了，如果想要兼容老版本，可在menuconfig中使能RT-Thread Components->Support legacy version for compatibility

由于elmfat文件系統(tǒng)默認(rèn)最大扇區(qū)大小為512，但這里使用的flash模塊W25Q128的Flash扇區(qū)大小為4096，為了將elmfat文件系統(tǒng)掛載到W25Q128上，Maximum sector size需要和W25Q128扇區(qū)大小保持一致，修改為4096，路徑：RT-Thread Components → DFS: device virtual file system → Enable elm-chan fatfs / elm-chan's FatFs, Generic FAT Filesystem Module

保存退出后使用scons --target=mdk5生成MDK5工程。

DFS文件系統(tǒng)DFS掛載到FAL分區(qū)測試

這里增加FAL flash抽象層，將elmfat文件系統(tǒng)掛載到W25Q128 flash設(shè)備的filesystem分區(qū)上，由于FAL管理的filesystem分區(qū)不是塊設(shè)備，需要先使用FAL分區(qū)轉(zhuǎn)BLK設(shè)備接口函數(shù)將filesystem分區(qū)轉(zhuǎn)換為塊設(shè)備，然后再將DFS elmfat文件系統(tǒng)掛載到filesystem塊設(shè)備上。

接下來修改fal_sample.c文件，修改后代碼：

/*
  * Copyright (c) 2006-2023, RT-Thread Development Team
  *
  * SPDX-License-Identifier: Apache-2.0
  *
  * Change Logs:
  * Date           Author       Notes
  * 2023-04-21     Wangyuqiang  the first version
  */


#include "rtthread.h"
#include "rtdevice.h"
#include "board.h"
#include "fal.h"


#include 


#define FS_PARTITION_NAME  "filesystem"


#define BUF_SIZE 1024


static int fal_test(const char *partiton_name)
{
int ret;
int i, j, len;
uint8_t buf[BUF_SIZE];
const struct fal_flash_dev *flash_dev = RT_NULL;
const struct fal_partition *partition = RT_NULL;


if (!partiton_name)
     {
         rt_kprintf("Input param partition name is null!
");
return -1;
     }


     partition = fal_partition_find(partiton_name);
if (partition == RT_NULL)
     {
         rt_kprintf("Find partition (%s) failed!
", partiton_name);
         ret = -1;
return ret;
     }


     flash_dev = fal_flash_device_find(partition->flash_name);
if (flash_dev == RT_NULL)
     {
         rt_kprintf("Find flash device (%s) failed!
", partition->flash_name);
         ret = -1;
return ret;
     }


     rt_kprintf("Flash device : %s   "
"Flash size : %dK   
"
"Partition : %s   "
"Partition size: %dK
",
                 partition->flash_name,
                 flash_dev->len/1024,
                 partition->name,
                 partition->len/1024);


/* erase all partition */
     ret = fal_partition_erase_all(partition);
if (ret < 0)
     {
         rt_kprintf("Partition (%s) erase failed!
", partition->name);
         ret = -1;
return ret;
     }
     rt_kprintf("Erase (%s) partition finish!
", partiton_name);


/* read the specified partition and check data */
for (i = 0; i < partition->len;)
     {
         rt_memset(buf, 0x00, BUF_SIZE);


         len = (partition->len - i) > BUF_SIZE ? BUF_SIZE : (partition->len - i);


         ret = fal_partition_read(partition, i, buf, len);
if (ret < 0)
         {
             rt_kprintf("Partition (%s) read failed!
", partition->name);
             ret = -1;
return ret;
         }


for(j = 0; j < len; j++)
         {
if (buf[j] != 0xFF)
             {
                 rt_kprintf("The erase operation did not really succeed!
");
                 ret = -1;
return ret;
             }
         }
         i += len;
     }


/* write 0x00 to the specified partition */
for (i = 0; i < partition->len;)
     {
         rt_memset(buf, 0x00, BUF_SIZE);


         len = (partition->len - i) > BUF_SIZE ? BUF_SIZE : (partition->len - i);


         ret = fal_partition_write(partition, i, buf, len);
if (ret < 0)
         {
             rt_kprintf("Partition (%s) write failed!
", partition->name);
             ret = -1;
return ret;
         }


         i += len;
     }
     rt_kprintf("Write (%s) partition finish! Write size %d(%dK).
", partiton_name, i, i/1024);


/* read the specified partition and check data */
for (i = 0; i < partition->len;)
     {
         rt_memset(buf, 0xFF, BUF_SIZE);


         len = (partition->len - i) > BUF_SIZE ? BUF_SIZE : (partition->len - i);


         ret = fal_partition_read(partition, i, buf, len);
if (ret < 0)
         {
             rt_kprintf("Partition (%s) read failed!
", partition->name);
             ret = -1;
return ret;
         }


for(j = 0; j < len; j++)
         {
if (buf[j] != 0x00)
             {
                 rt_kprintf("The write operation did not really succeed!
");
                 ret = -1;
return ret;
             }
         }


         i += len;
     }


     ret = 0;
return ret;
}


static void fal_sample(void)
{
/* 1- init */
     fal_init();


if (fal_test("font") == 0)
     {
         rt_kprintf("Fal partition (%s) test success!
", "font");
     }
else
     {
         rt_kprintf("Fal partition (%s) test failed!
", "font");
     }


if (fal_test("download") == 0)
     {
         rt_kprintf("Fal partition (%s) test success!
", "download");
     }
else
     {
         rt_kprintf("Fal partition (%s) test failed!
", "download");
     }
}
MSH_CMD_EXPORT(fal_sample, fal sample);


static void fal_elmfat_sample(void)
{
int fd, size;
struct statfs elm_stat;
struct fal_blk_device *blk_dev;
char str[] = "elmfat mount to W25Q flash.", buf[80];


/* fal init */
     fal_init();


/* create block device */
     blk_dev = (struct fal_blk_device *)fal_blk_device_create(FS_PARTITION_NAME);
if(blk_dev == RT_NULL)
         rt_kprintf("Can't create a block device on '%s' partition.
", FS_PARTITION_NAME);
else
         rt_kprintf("Create a block device on the %s partition of flash successful.
", FS_PARTITION_NAME);


/* make a elmfat format filesystem */
if(dfs_mkfs("elm", FS_PARTITION_NAME) == 0)
         rt_kprintf("make elmfat filesystem success.
");


/* mount elmfat file system to FS_PARTITION_NAME */
if(dfs_mount(FS_PARTITION_NAME, "/", "elm", 0, 0) == 0)
         rt_kprintf("elmfat filesystem mount success.
");


/* Get elmfat file system statistics */
if(statfs("/", &elm_stat) == 0)
         rt_kprintf("elmfat filesystem block size: %d, total blocks: %d, free blocks: %d.
",
                     elm_stat.f_bsize, elm_stat.f_blocks, elm_stat.f_bfree);


if(mkdir("/user", 0x777) == 0)
         rt_kprintf("make a directory: '/user'.
");


     rt_kprintf("Write string '%s' to /user/test.txt.
", str);


/* Open the file in create and read-write mode, create the file if it does not exist*/
     fd = open("/user/test.txt", O_WRONLY | O_CREAT);
if (fd >= 0)
     {
if(write(fd, str, sizeof(str)) == sizeof(str))
             rt_kprintf("Write data done.
");


         close(fd);   
     }


/* Open file in read-only mode */
     fd = open("/user/test.txt", O_RDONLY);
if (fd >= 0)
     {
         size = read(fd, buf, sizeof(buf));


         close(fd);


if(size == sizeof(str))
             rt_kprintf("Read data from file test.txt(size: %d): %s 
", size, buf);
     }
}
 MSH_CMD_EXPORT_ALIAS(fal_elmfat_sample, fal_elmfat,fal elmfat sample);

打開串口工具，輸入命令：

msh />fal_elmfat_sample

測試結(jié)果如下：




結(jié)語

本期我們介紹了FAL組件和DFS文件系統(tǒng)的功能特點(diǎn)和使用方法，下期將給大家介紹使用FAL分區(qū)管理與easyflash變量管理的第二部分，如何將EasyFlsh移植到FAL分區(qū)。靜待后續(xù)，下期見！

審核編輯：湯梓紅