When the -boot-info-table option is given, mkisofs will modify the boot file specified by the -b option by inserting a 56-byte "boot information table" at offset 8 in the file. This modification is done in the source file system, so make sure you use a copy if this file is not easily re-created! This file contains pointers, which may not be easily or reliably obtained at boot time.
The format of this table is as follows; all integers are in section 7.3.1 ("little endian") format.
Offset | Name | Size | Meaning |
|---|---|---|---|
8 | bi_pvd | 4 bytes | LBA of primary volume descriptor |
12 | bi_file | 4 bytes | LBA of boot file |
16 | bi_length | 4 bytes | Boot file length in bytes |
20 | bi_csum | 4 bytes | 32-bit checksum |
24 | bi_reserved | 40 bytes | Reserved |
The 32-bit checksum is the sum of all the 32-bit words in the boot file starting at byte offset 64. All linear block addresses (LBAs) are given in CD sectors (normally 2048 bytes).