📄 mp3_player_06.lss
字号:
12c0: 50 e0 ldi r21, 0x00 ; 0
return cnt;//return the free cluster number
}
}
}
return 1;//error
}
12c2: ca 01 movw r24, r20
12c4: b9 01 movw r22, r18
12c6: c0 50 subi r28, 0x00 ; 0
12c8: de 4f sbci r29, 0xFE ; 254
12ca: 0f b6 in r0, 0x3f ; 63
12cc: f8 94 cli
12ce: de bf out 0x3e, r29 ; 62
12d0: 0f be out 0x3f, r0 ; 63
12d2: cd bf out 0x3d, r28 ; 61
12d4: df 91 pop r29
12d6: cf 91 pop r28
12d8: 1f 91 pop r17
12da: 0f 91 pop r16
12dc: ff 90 pop r15
12de: ef 90 pop r14
12e0: df 90 pop r13
12e2: cf 90 pop r12
12e4: bf 90 pop r11
12e6: af 90 pop r10
12e8: 9f 90 pop r9
12ea: 8f 90 pop r8
12ec: 08 95 ret
000012ee <FAT_ModifyFAT>:
//在cluster指向的目录下找一个空位置记录文件
//find a position to place a item withe the given directory, the parameter is FileInfo who brought the message
unsigned int FAT_FindFreeItem(unsigned long cluster, struct FileInfoStruct *FileInfo)
{
BYTE *buffer;
DWORD tempclust;
DWORD sector;
unsigned int cnt;
unsigned int offset;
// unsigned char i;
struct direntry *item = 0;
if(cluster==0 && FAT32_Enable==0)// root directory//当这个目录是根目录
{
buffer=malloc(512);//apply memory
if(buffer==0)return 1;//if failed
for(cnt=0;cnt<RootDirSectors;cnt++)
{
if(FAT_ReadSector(FirstDirSector+cnt,buffer)){free(buffer);return 1;}//read sector
for(offset=0;offset<512;offset+=32)
{
item=(struct direntry *)(&buffer[offset]);
//used item
if(item->deName[0] == 0x00 || item->deName[0] == 0xe5)
//unused item
{
FileInfo->StartCluster = item->deStartCluster + (((unsigned long)item->deHighClust)<<16);//don't care
FileInfo->Size = item->deFileSize;//don't care
FileInfo->Attr = item->deAttributes;//don't care
FileInfo->Sector = FirstDirSector+cnt;//The key parameter record the secoter nuber which the item stored
FileInfo->Offset = offset; //The key parameter record the offset in the sector
free(buffer);//realease
return 0;//done
}
}
}
free(buffer);//release
}
else//other folders//当这是一个其它目录时，程序暂且没考虑到目录内没有空余项是需要另找一个簇来记录
{
tempclust=cluster;
while(1)
{
sector=(unsigned long)FirstDataSector+(tempclust-2)*(unsigned long)SectorsPerClust;//calculate the actual sector number
buffer=malloc(512);//apply memory
if(buffer==0)return 1;//if failed
for(cnt=0;cnt<SectorsPerClust;cnt++)
{
if(FAT_ReadSector(sector+cnt,buffer)){free(buffer);return 1;}
for(offset=0;offset<512;offset+=32)
{
item=(struct direntry *)(&buffer[offset]);
if(item->deName[0] == 0x00 || item->deName[0] == 0xe5)
{
FileInfo->StartCluster = item->deStartCluster + (((unsigned long)item->deHighClust)<<16);
FileInfo->Size = item->deFileSize;
FileInfo->Attr = item->deAttributes;
FileInfo->Sector = sector+cnt;
FileInfo->Offset = offset;
free(buffer);
return 0;
}
}
}
free(buffer);//release
tempclust=FAT_NextCluster(tempclust);//next cluster
if( (FAT32_Enable == 0 && tempclust == 0xffff) || tempclust == 0x0ffffff8 || tempclust == 0x0fffffff)return 1;
}
}
return 1;
}
//显示给定路径下的文件
//display the content of a foler , 0 as root directory
unsigned char FAT_DisDir(BYTE *dir)
{
BYTE *buffer;
DWORD sector;
DWORD cluster;
DWORD tempclust;
unsigned int cnt;
unsigned int offset;
unsigned char i;
struct direntry *item = 0;
cluster = FAT_OpenDir(dir);
if(cluster == 1)return 1;
if(cluster==0 && FAT32_Enable==0)// root directory
{
buffer=malloc(512);//apply memory
if(buffer==0)return 1;//if failed
for(cnt=0;cnt<RootDirSectors;cnt++)
{
if(FAT_ReadSector(FirstDirSector+cnt,buffer)){free(buffer);return 1;}
for(offset=0;offset<512;offset+=32)
{
item=(struct direntry *)(&buffer[offset]);//pointer convert
//find a valid item and display it
if((item->deName[0] != '.') && (item->deName[0] != 0x00) && (item->deName[0] != 0xe5) && (item->deAttributes != 0x0f))
{
USART_putchar(0x0d);
USART_putchar(0x0a);
for(i=0;i<8;i++)//name
{
USART_putchar(item->deName[i]);
}
if((item->deAttributes & 0x10)==0)USART_putchar('.');
for(i=0;i<3;i++)//extention
{
USART_putchar(item->deExtension[i]);
}
}
}
}
free(buffer);//release
}
else//other folders
{
tempclust=cluster;
while(1)
{
sector=(DWORD)FirstDataSector+(DWORD)(tempclust-2)*(DWORD)SectorsPerClust;//calculate the actual sector number
buffer=malloc(512);//apply memory
if(buffer==0)return 1;//if failed
for(cnt=0;cnt<SectorsPerClust;cnt++)
{
if(FAT_ReadSector(sector+cnt,buffer)){free(buffer);return 1;}
for(offset=0;offset<512;offset+=32)
{
item=(struct direntry *)(&buffer[offset]);
if((item->deName[0] != '.') && (item->deName[0] != 0x00) && (item->deName[0] != 0xe5) && (item->deAttributes != 0x0f))
{
USART_putchar(0x0d);
USART_putchar(0x0a);
for(i=0;i<8;i++)
{
USART_putchar(item->deName[i]);
}
if((item->deAttributes & 0x10)==0)USART_putchar('.');
for(i=0;i<3;i++)
{
USART_putchar(item->deExtension[i]);
}
}
}
}
free(buffer);//release
tempclust=FAT_NextCluster(tempclust);//next cluster
if( tempclust == 0x0ffffff8 )return 1;
if((FAT32_Enable == 0 && tempclust == 0xffff) || tempclust == 0x0fffffff)break;
}
}
return 0;
}
//在给定目录下查找文件
//Find a item in the directory which specify by the parameter "cluster"
//Return the start cluster number
unsigned int FAT_FindItem(unsigned long cluster, BYTE *name, struct FileInfoStruct *FileInfo)
{
BYTE *buffer;
DWORD tempclust;
DWORD sector;
unsigned int cnt;
unsigned int offset;
unsigned char i;
struct direntry *item = 0;
if((cluster==0) && (FAT32_Enable == 0))// root directory
{
buffer=malloc(512);//apply memory
if(buffer==0)return 1;//if failed
for(cnt=0;cnt<RootDirSectors;cnt++)
{
if(FAT_ReadSector(FirstDirSector+cnt,buffer)){free(buffer);return 1;}
for(offset=0;offset<512;offset+=32)
{
item=(struct direntry *)(&buffer[offset]);
if((item->deName[0] != 0x00) && (item->deName[0] != 0xe5) && (item->deAttributes != 0x0f))
{
for(i=0;i<11;i++)
{
if(buffer[offset+i]!=name[i])break;
}
if(i==11)
{
//return the parameter of the item
FileInfo->StartCluster = item->deStartCluster + (((unsigned long)item->deHighClust)<<16);//don't care
FileInfo->Size = item->deFileSize;
FileInfo->Attr = item->deAttributes;
FileInfo->Sector = FirstDirSector+cnt;
FileInfo->Offset = offset;
free(buffer);
return 0;
}
}
}
}
free(buffer);//release
}
else//other folders
{
tempclust=cluster;
while(1)
{
sector=(DWORD)FirstDataSector+(DWORD)(tempclust-2)*(DWORD)SectorsPerClust;//calculate the actual sector number
buffer=malloc(512);//apply memory
if(buffer==0)return 1;//if failed
for(cnt=0;cnt<SectorsPerClust;cnt++)
{
if(FAT_ReadSector(sector+cnt,buffer)){free(buffer);return 1;}
for(offset=0;offset<512;offset+=32)
{
item=(struct direntry *)(&buffer[offset]);
if((item->deName[0] != 0x00) && (item->deName[0] != 0xe5) && (item->deAttributes != 0x0f))
{
for(i=0;i<11;i++)
{
if(buffer[offset+i]!=name[i])break;
}
if(i==11)
{
FileInfo->StartCluster = item->deStartCluster + (((unsigned long)item->deHighClust)<<16);//don't care
FileInfo->Size = item->deFileSize;
FileInfo->Attr = item->deAttributes;
FileInfo->Sector = sector+cnt;
FileInfo->Offset = offset;
free(buffer);
return 0;
}
}
}
}
free(buffer);//release
tempclust=FAT_NextCluster(tempclust);//next cluster
if((FAT32_Enable == 0 && tempclust == 0xffff) || tempclust == 0x0ffffff8 || tempclust == 0x0fffffff)break;
}
}
return 1;
}
//挑选一个未使用的记录项
//select the first unsed item in the given cluster
//for delete a foler or a file
unsigned char FAT_SelectOneItem(unsigned long cluster,struct FileInfoStruct *FileInfo)
{
BYTE *buffer;
DWORD tempclust;
DWORD sector;
unsigned int cnt;
unsigned int offset;
// unsigned char i;
struct direntry *item = 0;
if(cluster==0 && FAT32_Enable==0)// root directory
{
buffer=malloc(512);//apply memory
if(buffer==0)return 1;//if failed
for(cnt=0;cnt<RootDirSectors;cnt++)
{
if(FAT_ReadSector(FirstDirSector+cnt,buffer)){free(buffer);return 1;}
for(offset=0;offset<512;offset+=32)
{
item=(struct direntry *)(&buffer[offset]);
if((item->deName[0] != 0x00) && (item->deName[0] != 0xe5) && (item->deAttributes != 0x0f))
{
//return the parameter of the item
FileInfo->StartCluster = item->deStartCluster + (((unsigned long)item->deHighClust)<<16);//don't care
FileInfo->Size = item->deFileSize;
FileInfo->Attr = item->deAttributes;
FileInfo->Sector = FirstDirSector+cnt;
FileInfo->Offset = offset;
free(buffer);
return 0;
}
}
}
free(buffer);//release
}
else//other folders
{
tempclust=cluster;
while(1)
{
sector=(DWORD)FirstDataSector+(DWORD)(tempclust-2)*(DWORD)SectorsPerClust;//calculate the actual sector number
buffer=malloc(512);//apply memory
if(buffer==0)return 1;//if failed
for(cnt=0;cnt<SectorsPerClust;cnt++)
{
if(FAT_ReadSector(sector+cnt,buffer)){free(buffer);return 1;}
for(offset=0;offset<512;offset+=32)
{
item=(struct direntry *)(&buffer[offset]);
if((item->deName[0] != 0x2e) && (item->deName[0] != 0x00) && (item->deName[0] != 0xe5) & (item->deAttrib⌨️ 快捷键说明
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