Bootable CD-ROM Format Specification

2.5 Section Entry Extension

Section Entry Extension must follow a Section Entry. This Extension defines additional selection criteria. When the

13 bytes provided by the Section entry are insufficient for representing the selection criteria a Section Entry Extension

should immediately follow the Section Entry. Several Section Entry Extensions may be chained together by setting

bit 5 of byte 1 for as many Extensions as necessary. The final extension should have bit 5 clear (set to 0) to indicate

that no more Extensions follow. See Figure 6 for a description of the Section Entry Extension

Offset Type Description

0 Byte Header ID, must be 01

1 Byte Platform ID

0 = 80x86

1=Power PC

2=Mac

2-3 Word Reserved, must be 0

4-1B Character ID string. This is intended to identify the manufacturer/developer of

the CD-ROM.

1C-1D Integer Checksum Word. This sum of all the words in this record should be

1E Byte Key byte, must be 55. This value is included in the checksum.

1F Byte Key byte, must be AA. This value is included in the checksum.

Figure 2 - Validation Entry