User`s manual

PBOOT - Bootstrap Operating System
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3
The layout of the boot record must be designed as shown in the
Figure 3-1. The first 446 bytes of the boot record contain a PC
compatibility block, the next four entries contain a partition table
totaling 64 bytes, and last two bytes contain a signature.
Figure 3-2 identifies the PowerPC Reference Platform partition
table entry by the $41 value in the system indicator field.
All other fields are ignored by the debugger except for the
beginning sector and number of sectors fields. Note that these are
really not sector entities, but logical block entities. The logical block
size is 512 bytes, the same size as the boot record.
0
PC Compatibility Block
in the Boot Record
0
$1BE
Partition Entry 1
446
$1CE
Partition Entry 2
462
$1DE
Partition Entry 3
478
$1EE
Partition Entry 4
494
$1FE
$55 $AA
510
512
Figure 3-1. Boot Record