here - OSTA - Optical Storage Technology Association

More documents

Recommendations

Info

• Bits 1-7: Reserved. Shall be set to zero on write, and ignored on read. NOTE: The Metadata Partition shall have an entry in the LVID Size and Free space tables (see2.2.6). NOTE: The Metadata File Location, Metadata Mirror File Location and Metadata Bitmap File Location Uint32 fields define File Entry locations. The number of blocks allocated for each File Entry shall be one logical block. 2.2.102.2.11 Virtual Allocation Table The Virtual Allocation Table (VAT) is used on sequentially written media (eg. CD-R) to give the appearance of randomly writable media to the system. The existence of this partition is identified in the partition maps. The VAT shall only be recorded on sequentially written media (eg. CD-R). The VAT is a map that translates Virtual Addresses to logical addresses. It shall be recorded as a file identified by a File Entry ICB (VAT ICB) that allows great flexibility in building the table. The VAT ICB is the last sector recorded in any transaction. The VAT itself may be recorded at any location. The VAT shall be identified by a File Entry ICB with a file type of 248. This ICB shall be the last valid data sector recorded. Error recovery schemes can find the last valid VAT by finding ICBs with file type 248. This file, when small, can be embedded in the ICB that describes it. If it is larger, it can be recorded in a sector or sectors preceding the ICB. The sectors do not have to be contiguous, which allows writing only new parts of the table if desired. This allows small incremental updates, even on disks with many directories. When the VAT is small (a small number of directories on the disk), the VAT is updated by writing a new file ICB with the VAT embedded. When the VAT becomes too large to fit in the ICB, writing a single sector with the VAT and a second sector with the ICB is required. Beyond this point, more than one sector is required for the VAT. However, as multiple extents are supported, updating the VAT may consist of writing only the sector or sectors that need updating and writing the ICB with pointers to all of the pieces of the VAT. The Virtual Allocation Table is used to redirect requests for certain information to the proper logical location. The indirection provided by this table provides the appearance of direct overwrite capability. For example, the ICB describing the root directory could be referenced as virtual sector 1. A virtual sector is contained in a partition identified by a virtual partition map entry. Over the course of updating the disk, the root directory may change. When it changes, a new sector describing the root directory is written, and its Logical Block Address is recorded as the Logical Block Address corresponding to virtual sector 1. Nothing that references virtual sector 1 needs to change, as it still points to the UDF 2.01 35 March50 April
most current virtual sector 1 that exists, even though it exists at a new Logical Block Address. The use of virtual addressing allows any desired structure to become effectively rewritable. The structure is rewritable when every pointer that references it does so only by its Virtual Address. When a replacement structure is written, the virtual reference does not need to change. The proper entry in the VAT is changed to reflect the new Logical Block Address of the corresponding Virtual Address and all virtual references then indirectly point to the new structure. All structures that require updating, such as directory ICBs, shall be referenced by a Virtual Address. As each structure is updated, its corresponding entry in the VAT ICB shall be updated. The VAT shall be recorded as a sequence of Uint32 entries in a file. Each entry shall be the offset, in sectors, into the physical partition in which the VAT is located. The first entry shall be for the virtual partition sector 0, the second entry for virtual partition sector 1, etc. The Uint32 entries shall follow the VAT header. The entry for the previous VAT ICB allows for viewing the file system as it appeared in an earlier state. If this field is #FFFFFFFF, then no such ICB is specified. UDF 2.01 36 March50 April
Page 1 and 2: Universal Disk Format ® Specificat
Page 3 and 4: REVISION HISTORY 1.00 October 24, 1
Page 6 and 7: CONTENTS 1. INTRODUCTION ..........
Page 8 and 9: 6.4 OSTA Compressed Unicode Algorit
Page 10 and 11: 1. Introduction The OSTA Universal
Page 12 and 13: 1.2 Compliance This document requir
Page 14 and 15: Media Block Address NOTE 1: This is
Page 16 and 17: 1.3.3 Terms May Optional Shall Shou
Page 18 and 19: non-overlapping Partitions with 2 p
Page 20 and 21: 2.1 Part 1 - General 2.1.1 Characte
Page 22 and 23: length of the field. The characters
Page 24 and 25: 2.1.5.2 char Identifier[23] Unless
Page 26 and 27: The Suffix Type column in the above
Page 28 and 29: For an Application Entity Identifie
Page 30 and 31: 2.2 Part 3 - Volume Structure 2.2.1
Page 32 and 33: NOTE: This field is used to determi
Page 34 and 35: 2.2.4 Logical Volume Descriptor str
Page 36 and 37: 2.2.5 Unallocated Space Descriptor
Page 38 and 39: EntityID. The scope of this EntityI
Page 40 and 41: 2.2.7.2.2 dstring LogicalVolumeIden
Page 42 and 43: Layout of Type 2 partition map for
Page 46 and 47: Virtual Allocation Table structure
Page 48 and 49: the offset and length of a partitio
Page 50 and 51: The Metadata Partition Map (see2.2.
Page 52 and 53: 2.2.13.1 Metadata File (and Metadat
Page 54 and 55: 2.2.13.4 Procedure for de-allocatin
Page 56 and 57: } struct EntityID byte byte Impleme
Page 58 and 59: 2.3.2 File Set Descriptor struct Fi
Page 60 and 61: 2.3.2.7 struct EntityID DomainIdent
Page 62 and 63: In order to assist a UDF implementa
Page 64 and 65: 2.3.5.1 Uint16 StrategyType The co
Page 66 and 67: 2.3.6 File Entry struct FileEntry {
Page 68 and 69: 2.3.6.8 FileLinkCount Hard links to
Page 70 and 71: Descriptors should be used. For exa
Page 72 and 73: 2.3.11.2 Uint32 PreviousAllocationE
Page 74 and 75: 3.2 Part 3 - Volume Structure 3.2.1
Page 76 and 77: 3.3 Part 4 - File System 3.3.1 File
Page 78 and 79: 3.3.2.1.2 Macintosh Bits 6 & 7 (Set
Page 80 and 81: 3.3.3 File Entry struct FileEntry {
Page 82 and 83: would be considered writable if the
Page 84 and 85: 3.3.3.5 byte Extended Attributes Se
Page 86 and 87: ignored and the file creation time
Page 88 and 89: 3.3.4.5.1.1 FreeEASpace This extend
Page 90 and 91: MacVolumeInfo format RBP Length Nam
Page 92 and 93: UDFFXInfo format (Volume IV, page 1
Page 94 and 95:
The ApplicationUse area for this ex
Page 96 and 97:
stream directory. If present, there
Page 98 and 99:
Since the streams listed above have
Page 100 and 101:
Object Logical Block Number is the
Page 102 and 103:
mechanism for the host software to
Page 104 and 105:
Vendor ID - The Vendor ID reported
Page 106 and 107:
The OS2EA Stream contains a table o
Page 108 and 109:
4.2.2 File Identifier Descriptor st
Page 110 and 111:
Definitions: A FileIdentifier shall
Page 112 and 113:
3. Invalid Characters: A FileIdenti
Page 114 and 115:
4. Trailing Periods and Spaces: All
Page 116 and 117:
If there is a file extension then t
Page 118 and 119:
defined as space that is not direct
Page 120 and 121:
UDF 2.01 111 March50 April
Page 122 and 123:
6.2 UDF Entity Identifier Values En
Page 124 and 125:
8 0 BeOS - generic 9 0 Windows CE -
Page 126 and 127:
} } returnValue = unicodeIndex; } r
Page 128 and 129:
} return crc; #ifdef MAIN unsigned
Page 130 and 131:
6.6 Algorithm for Strategy Type 409
Page 132 and 133:
nameLen = udfNameLen; } else { /* A
Page 134 and 135:
} needsCRC = TRUE; /* Append the CR
Page 136 and 137:
if (index < udfLabelLen || index ==
Page 138 and 139:
UDF 2.01 129 March50 April
Page 140 and 141:
unicode_t *udfName, /* (Input) Name
Page 142 and 143:
} #ifdef (OS2 | WIN_95 | WIN_NT) /*
Page 144 and 145:
6.8 Extended Attribute Checksum Alg
Page 146 and 147:
• The data of each file shall be
Page 148 and 149:
Read the File Identifier Descriptor
Page 150 and 151:
• An intermediate state is allowe
Page 152 and 153:
• The host shall perform read/mod
Page 154 and 155:
6.10.2.6.3 Level 3 No restrictions
Page 156 and 157:
ISO 9660 converted to UDF 1 st sess
Page 158 and 159:
For File Structure: 5. Unallocated
Page 160 and 161:
6.13 Recommendations for DVD+R and
Page 162 and 163:
6.13.1.4.2 Anchor Volume Descriptor
Page 164 and 165:
6.13.2.1 Requirements • The packe
Page 166 and 167:
6.126.15 UDF Media Format Revision
Page 168 and 169:
Description DCN Updated in UDF Revi
Page 170 and 171:
Registration Form Disk Format Speci
Page 172 and 173:
L Logical Block Size, 8, 9, 2425 Lo
show all

here - OSTA - Optical Storage Technology Association

Create successful ePaper yourself

Delete template?

Save as template?