Hi all, Excuse me. ˇ·However, calculations limit any one partition to *2^31* chunks in total. ie a ˇ·total partition of *2^41*. Chunk ID is 32 bit long. That should be 2^32 in paper. But I don't know why Charles means 2^31 here. Are there 2 id can't be used in defalut or Is it his carelessness? So that should be 2^32 ^ 2^11= 2^43B, when Chunk size is 2kb. Thanks! > > > 2008/10/21 Charles Manning > > >> > Hi >> > I want to know clearly the maximam file system size for YAFFS2 can >> > handle. >> > In file ysffs_guts.h, there're ysffs_Tags structure: >> > typedef struct { >> > unsigned chunkId:20; >> > unsigned serialNumber:2; >> > unsigned byteCount:10; >> > unsigned objectId:18; >> > unsigned ecc:12; >> > unsigned unusedStuff:2; >> > >> > } yaffs_Tags; >> > I can calculate the maximum file system size YAFFS2 can handle by >> > following algorithm: >> > (2^20)*(2^18)*(2kb)= 2^49B //Chunk size is 2kb >> > Am I right? >> > Appreciate for your reply! Thanks. >> >> While you have chosen the wrong structure here (yaffs_Tags is only >> relevent to >> the yaffs1 mode of operation), the basic idea is almost correct. >> >> yaffs2 uses the yaffs_PackedTags2 structure. This allows up to 32 bits for >> the >> chunk Id. That limits any particular file to 2^42 (assuming 2048-byte >> chunks). >> >> However, calculations limit any one partition to 2^31 chunks in total. ie >> a >> total partition of 2^41. >> >> However, all the structures use RAM and thus real-world RAM limitations >> are >> more likely to cause problems first. >> >> -- Charles >> >> >> >> >> > >