Todd Vierling <tv@wasabisystems.com> writes:

> ** prep **
> 
> Uses MBR with partition type 0x41 (MBR_PTYPE_PREP), and does not directly
> execute code in the MBR block.  I don't know how many sectors are loaded
> from that partition for boot code.

The image length, in bytes, is specified by the Load Image Length
field (32 bits wide, LE) located at offset 516 into the MBR_PTYPE_PREP
partition.

As an amusing sidenote, the PReP specification suggests writing i386
code to the MBR which, "when executed on an x86 machine, [...]
displays a message indicating that this partition is not applicable to
the current system environment."


- Klaus