From 4aca87515a5083ae0e31ce3177189fd43b6d05ac Mon Sep 17 00:00:00 2001 From: Andreas Baumann Date: Sat, 3 Jan 2015 13:58:15 +0100 Subject: patch to Vanilla Tomato 1.28 --- .../linux/linux/scripts/squashfs/lzma/7zFormat.txt | 471 +++++++++++++++++++++ 1 file changed, 471 insertions(+) create mode 100644 release/src/linux/linux/scripts/squashfs/lzma/7zFormat.txt (limited to 'release/src/linux/linux/scripts/squashfs/lzma/7zFormat.txt') diff --git a/release/src/linux/linux/scripts/squashfs/lzma/7zFormat.txt b/release/src/linux/linux/scripts/squashfs/lzma/7zFormat.txt new file mode 100644 index 00000000..7e2b14ad --- /dev/null +++ b/release/src/linux/linux/scripts/squashfs/lzma/7zFormat.txt @@ -0,0 +1,471 @@ +7z Format description (2.30 Beta 25) +----------------------------------- + +This file contains description of 7z archive format. +7z archive can contain files compressed with any method. +See "Methods.txt" for description for defined compressing methods. + + +Format structure Overview +------------------------- + +Some fields can be optional. + +Archive structure +~~~~~~~~~~~~~~~~~ +SignatureHeader +[PackedStreams] +[PackedStreamsForHeaders] +[ + Header + or + { + Packed Header + HeaderInfo + } +] + + + +Header structure +~~~~~~~~~~~~~~~~ +{ + ArchiveProperties + AdditionalStreams + { + PackInfo + { + PackPos + NumPackStreams + Sizes[NumPackStreams] + CRCs[NumPackStreams] + } + CodersInfo + { + NumFolders + Folders[NumFolders] + { + NumCoders + CodersInfo[NumCoders] + { + ID + NumInStreams; + NumOutStreams; + PropertiesSize + Properties[PropertiesSize] + } + NumBindPairs + BindPairsInfo[NumBindPairs] + { + InIndex; + OutIndex; + } + PackedIndices + } + UnPackSize[Folders][Folders.NumOutstreams] + CRCs[NumFolders] + } + SubStreamsInfo + { + NumUnPackStreamsInFolders[NumFolders]; + UnPackSizes[] + CRCs[] + } + } + MainStreamsInfo + { + (Same as in AdditionalStreams) + } + FilesInfo + { + NumFiles + Properties[] + { + ID + Size + Data + } + } +} + +HeaderInfo structure +~~~~~~~~~~~~~~~~~~~~ +{ + (Same as in AdditionalStreams) +} + + + +Notes about Notation and encoding +--------------------------------- + +7z uses little endian encoding. + +7z archive format has optional headers that are marked as +[] +Header +[] + +REAL_UINT64 means real UINT64. + +UINT64 means real UINT64 encoded with the following scheme: + + Size of encoding sequence depends from first byte: + First_Byte Extra_Bytes Value + (binary) + 0xxxxxxx : ( xxxxxxx ) + 10xxxxxx BYTE y[1] : ( xxxxxx << (8 * 1)) + y + 110xxxxx BYTE y[2] : ( xxxxx << (8 * 2)) + y + ... + 1111110x BYTE y[6] : ( x << (8 * 6)) + y + 11111110 BYTE y[7] : y + 11111111 BYTE y[8] : y + + + +Property IDs +------------ + +0x00 = kEnd, + +0x01 = kHeader, + +0x02 = kArchiveProperties, + +0x03 = kAdditionalStreamsInfo, +0x04 = kMainStreamsInfo, +0x05 = kFilesInfo, + +0x06 = kPackInfo, +0x07 = kUnPackInfo, +0x08 = kSubStreamsInfo, + +0x09 = kSize, +0x0A = kCRC, + +0x0B = kFolder, + +0x0C = kCodersUnPackSize, +0x0D = kNumUnPackStream, + +0x0E = kEmptyStream, +0x0F = kEmptyFile, +0x10 = kAnti, + +0x11 = kName, +0x12 = kCreationTime, +0x13 = kLastAccessTime, +0x14 = kLastWriteTime, +0x15 = kWinAttributes, +0x16 = kComment, + +0x17 = kEncodedHeader, + + +7z format headers +----------------- + +SignatureHeader +~~~~~~~~~~~~~~~ + BYTE kSignature[6] = {'7', 'z', 0xBC, 0xAF, 0x27, 0x1C}; + + ArchiveVersion + { + BYTE Major; // now = 0 + BYTE Minor; // now = 2 + }; + + UINT32 StartHeaderCRC; + + StartHeader + { + REAL_UINT64 NextHeaderOffset + REAL_UINT64 NextHeaderSize + UINT32 NextHeaderCRC + } + + +........................... + + +ArchiveProperties +~~~~~~~~~~~~~~~~~ +BYTE NID::kArchiveProperties (0x02) +while(true) +{ + BYTE PropertyType; + if (aType == 0) + break; + UINT64 PropertySize; + BYTE PropertyData[PropertySize]; +} + + +Digests (NumStreams) +~~~~~~~~~~~~~~~~~~~~~ + BYTE AllAreDefined + if (AllAreDefined == 0) + { + for(NumStreams) + BIT Defined + } + UINT32 CRCs[NumDefined] + + +PackInfo +~~~~~~~~~~~~ + BYTE NID::kPackInfo (0x06) + UINT64 PackPos + UINT64 NumPackStreams + + [] + BYTE NID::kSize (0x09) + UINT64 PackSizes[NumPackStreams] + [] + + [] + BYTE NID::kCRC (0x0A) + PackStreamDigests[NumPackStreams] + [] + + BYTE NID::kEnd + + +Folder +~~~~~~ + UINT64 NumCoders; + for (NumCoders) + { + BYTE + { + 0:3 DecompressionMethod.IDSize + 4: + 0 - IsSimple + 1 - Is not simple + 5: + 0 - No Attributes + 1 - There Are Attributes + 7: + 0 - Last Method in Alternative_Method_List + 1 - There are more alternative methods + } + BYTE DecompressionMethod.ID[DecompressionMethod.IDSize] + if (!IsSimple) + { + UINT64 NumInStreams; + UINT64 NumOutStreams; + } + if (DecompressionMethod[0] != 0) + { + UINT64 PropertiesSize + BYTE Properties[PropertiesSize] + } + } + + NumBindPairs = NumOutStreamsTotal - 1; + + for (NumBindPairs) + { + UINT64 InIndex; + UINT64 OutIndex; + } + + NumPackedStreams = NumInStreamsTotal - NumBindPairs; + if (NumPackedStreams > 1) + for(NumPackedStreams) + { + UINT64 Index; + }; + + + + +Coders Info +~~~~~~~~~~~ + + BYTE NID::kUnPackInfo (0x07) + + + BYTE NID::kFolder (0x0B) + UINT64 NumFolders + BYTE External + switch(External) + { + case 0: + Folders[NumFolders] + case 1: + UINT64 DataStreamIndex + } + + + BYTE ID::kCodersUnPackSize (0x0C) + for(Folders) + for(Folder.NumOutStreams) + UINT64 UnPackSize; + + + [] + BYTE NID::kCRC (0x0A) + UnPackDigests[NumFolders] + [] + + + + BYTE NID::kEnd + + + +SubStreams Info +~~~~~~~~~~~~~~ + BYTE NID::kSubStreamsInfo; (0x08) + + [] + BYTE NID::kNumUnPackStream; (0x0D) + UINT64 NumUnPackStreamsInFolders[NumFolders]; + [] + + + [] + BYTE NID::kSize (0x09) + UINT64 UnPackSizes[] + [] + + + [] + BYTE NID::kCRC (0x0A) + Digests[Number of streams with unknown CRC] + [] + + + BYTE NID::kEnd + + +Streams Info +~~~~~~~~~~~~ + + [] + PackInfo + [] + + + [] + CodersInfo + [] + + + [] + SubStreamsInfo + [] + + BYTE NID::kEnd + + +FilesInfo +~~~~~~~~~ + BYTE NID::kFilesInfo; (0x05) + UINT64 NumFiles + + while(true) + { + BYTE PropertyType; + if (aType == 0) + break; + + UINT64 Size; + + switch(PropertyType) + { + kEmptyStream: (0x0E) + for(NumFiles) + BIT IsEmptyStream + + kEmptyFile: (0x0F) + for(EmptyStreams) + BIT IsEmptyFile + + kAnti: (0x10) + for(EmptyStreams) + BIT IsAntiFile + + case kCreationTime: (0x12) + case kLastAccessTime: (0x13) + case kLastWriteTime: (0x14) + BYTE AllAreDefined + if (AllAreDefined == 0) + { + for(NumFiles) + BIT TimeDefined + } + BYTE External; + if(External != 0) + UINT64 DataIndex + [] + for(Definded Items) + UINT32 Time + [] + + kNames: (0x11) + BYTE External; + if(External != 0) + UINT64 DataIndex + [] + for(Files) + { + wchar_t Names[NameSize]; + wchar_t 0; + } + [] + + kAttributes: (0x15) + BYTE AllAreDefined + if (AllAreDefined == 0) + { + for(NumFiles) + BIT AttributesAreDefined + } + BYTE External; + if(External != 0) + UINT64 DataIndex + [] + for(Definded Attributes) + UINT32 Attributes + [] + } + } + + +Header +~~~~~~ + BYTE NID::kHeader (0x01) + + [] + ArchiveProperties + [] + + [] + BYTE NID::kAdditionalStreamsInfo; (0x03) + StreamsInfo + [] + + [] + BYTE NID::kMainStreamsInfo; (0x04) + StreamsInfo + [] + + [] + FilesInfo + [] + + BYTE NID::kEnd + + +HeaderInfo +~~~~~~~~~~ + [] + BYTE NID::kEncodedHeader; (0x17) + StreamsInfo for Encoded Header + [] + + +--- +End of document -- cgit v1.2.3-54-g00ecf