FAT: Difference between revisions
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→FAT 12: more robust fat entry decode section for fat12 |
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If "table_value" is greater than or equal to (>=) 0xFF8 then there are no more clusters in the chain. This means that the whole file has been read. If "table_value" equals (==) 0xFF7 then this cluster has been marked as "bad". "Bad" clusters are prone to errors and should be avoided. If "table_value" is not one of the above cases then it is the cluster number of the next cluster in the file. |
If "table_value" is greater than or equal to (>=) 0xFF8 then there are no more clusters in the chain. This means that the whole file has been read. If "table_value" equals (==) 0xFF7 then this cluster has been marked as "bad". "Bad" clusters are prone to errors and should be avoided. If "table_value" is not one of the above cases then it is the cluster number of the next cluster in the file. |
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The entries under index 0 and 1 are reserved. Index 0 is used as value |
The entries under index 0 and 1 are reserved. Index 0 is used as a value in other entries signifying that the given cluster is free, with the corresponding first entry in the table holding the value of the BPB_Media field in its low 8 bits and 0xf in its top 4 bits. For example, if BPB_Media is 0xF8, then the zeroth entry should hold the value 0xFF8. The second entry (index 1) is unused but must hold the value 0xFFF. |
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FAT12 uses an entry size that is not evenly divisible by 8 bits. This has some consequences. |
FAT12 uses an entry size that is not evenly divisible by 8 bits. This has some consequences. |