/************************************************************************************
??本程序僅供廣大電子愛(ài)好者制作MP3學(xué)習(xí)和參考使用，不得用于其它用途，否則后果自負(fù)
??
??file_system.c?file
??Created?by?Computer-lov.?Date:?2005.3.19
??Last?edited?date:?2005.5.31
??version?1.1
??Copyright?（c）?2005?Computer-lov
??All?rigths?reserved
*************************************************************************************/

#include?“file_system.h“
#include?“IDE.H“
#include?“hardware.h“
#include?“l(fā)cd.h“
#include?“mp3.h“
#include?“keyboard.h“


FILE?xdata?file;
unsigned?int?dir_length;?????//文件名長(zhǎng)度
unsigned?int?folder_length;??//文件夾名長(zhǎng)度

////////////////////////////////////??判斷是否為一個(gè)?MP3?文件???///////////////////////////////
unsigned?char?is_a_mp3_file（void）
{
?if（（file.name[0]==0x00）||（file.name[0]==0xE5）||（file.name[0]==‘.‘））return?0;
?if（file.attribute==0x0F）return?0;??//此項(xiàng)目為長(zhǎng)文件名項(xiàng)目
?if（file.attribute?&?0x04）return?0;??//此文件為系統(tǒng)文件
?if（file.attribute?&?0x08）return?0;??//此項(xiàng)目為系統(tǒng)標(biāo)卷
?if（file.attribute?&?0x10）return?0;??//此項(xiàng)目為子目錄
?if（（file.name[8]==‘M‘）&&（file.name[9]==‘P‘）&&（file.name[10]==‘3‘））return?1;
?else?return?0;
}
///////////////////////////////////////////////////////////////////////////////////////////////

unsigned?long?int?LAST_FAT_LBA;?
//最后一次讀取FAT時(shí)的邏輯塊地址，用來(lái)判斷本次讀取是否需要重新從硬盤中讀取，以加快速度
unsigned?int?disp_count=0;
unsigned?char?disp_time;

////////////////////////////////////////////////////////////////////////////////////////////////
unsigned?long?int?get_next_sector（void）??//根據(jù)當(dāng)前簇號(hào)，獲取下一個(gè)扇區(qū)地址
{
?unsigned?long?int?LBA;
?unsigned??int?i;
?LBA=（file.next_cluster_number）/（（dbr[driver_number].bytes_per_sectors）/4）;??//計(jì)算扇區(qū)地址
?i=（file.next_cluster_number）*4-LBA*dbr[driver_number].bytes_per_sectors;?//計(jì)算偏移地址
?if（LAST_FAT_LBA!=LBA）??????????????????//如果數(shù)據(jù)不在FAT_buffer[]中，則需要重新讀取
??{
???LAST_FAT_LBA=LBA;
???LBA=LBA+FAT_start_sector[driver_number];
???read_IDE_FAT_sector（LBA）;
??}
?（（unsigned?char?*）&（file.next_cluster_number））[3]=FAT_buffer[i];
?i++;
?（（unsigned?char?*）&（file.next_cluster_number））[2]=FAT_buffer[i];
?i++;
?（（unsigned?char?*）&（file.next_cluster_number））[1]=FAT_buffer[i];
?i++;
?（（unsigned?char?*）&（file.next_cluster_number））[0]=FAT_buffer[i];??//獲取下一簇號(hào)
?LBA=file.next_cluster_number-（dbr[driver_number].root_cluster_num）;???????????????????????????????????//保存簇號(hào)
?LBA=LBA*（dbr[0].sectors_per_cluster）+DATA_start_sector[0];????????//轉(zhuǎn)換成扇區(qū)地址
//?IDE_LED=!IDE_LED;?????????????????????????????????????????????????//硬盤指示燈閃爍
?disp_time++;
?if（disp_time>3）
??{
???disp_time=0;?
???LCD_go_home（）;
???disp_count+=2;
???for（i=0;i<14;i++）write_LCD_data（（（unsigned?char?*）dir_name）[（i+disp_count）%（dir_length+4）]）;
??}??
?return?LBA;
}
////////////////////////////////////////////////////////////////////////////////////////////////

/////////////////////////////////////////////////??獲取文件夾的下一扇區(qū)地址??///////////////////
unsigned?long?int?get_dir_next_sector（void）
{
?unsigned?long?int?LBALBA2;
?unsigned?int?i;
?LBA=current_dir.curren

?屬性????????????大小?????日期????時(shí)間???名稱
-----------?---------??----------?-----??----

?????文件????????865??2006-03-02?23:11??MP3_OK\MP3.h

?????文件??????17650??2006-03-02?23:11??MP3_OK\file_system.c

?????文件??????14225??2006-03-02?23:11??MP3_OK\IDE.C

?????文件???????2767??2006-03-02?23:11??MP3_OK\Initial.c

?????文件???????1030??2006-03-02?23:11??MP3_OK\keyboard.c

?????文件???????4825??2006-03-02?23:11??MP3_OK\LCD.C

?????文件???????4930??2006-03-02?23:13??MP3_OK\main.c

?????文件???????7648??2006-03-02?23:11??MP3_OK\MP3.c

?????文件???????7809??2005-04-06?18:53??MP3_OK\MP32.c

?????文件??????25805??2006-03-02?23:11??MP3_OK\Usb.c

?????文件???????7872??2005-04-02?19:50??MP3_OK\AT89C51SND1C.h

?????文件???????1909??2006-03-02?23:11??MP3_OK\file_system.h

?????文件???????1197??2006-03-02?23:11??MP3_OK\hardware.h

?????文件???????5825??2006-03-02?23:11??MP3_OK\IDE.h

?????文件???????2259??2006-03-02?23:11??MP3_OK\Initial.h

?????文件????????635??2006-03-02?23:11??MP3_OK\Keyboard.h

?????文件????????845??2006-03-02?23:11??MP3_OK\LCD.H

?????文件???????2474??2005-06-17?19:07??MP3_OK\MASS_STORAGE.H

?????文件?????119327??2006-03-02?23:08??MP3_OK\UNICODE.H

?????文件???????6255??2005-06-17?19:06??MP3_OK\USB.H

?????文件???????2619??2005-05-31?18:09??MP3_OK\MP3.Uv2

?????文件????????161??2006-03-02?23:12??MP3_OK\MP3.plg

?????文件?????115079??2006-03-02?23:11??MP3_OK\MP3.M51

?????文件?????124125??2006-03-02?23:11??MP3_OK\MP3.hex

?????文件???????7794??2006-03-02?23:11??MP3_OK\main.LST

?????文件??????23821??2006-03-02?23:11??MP3_OK\main.OBJ

?????文件??????21704??2006-03-02?23:11??MP3_OK\IDE.LST

?????文件??????33689??2006-03-02?23:11??MP3_OK\IDE.OBJ

?????文件??????25563??2006-03-02?23:11??MP3_OK\file_system.LST

?????文件??????48589??2006-03-02?23:11??MP3_OK\file_system.OBJ

............此處省略17個(gè)文件信息