On Tue, 12 Mar 2002, Luke Mewburn wrote:

> 4. Existing situation
> ---------------------

 * mvmeppc
	- Same as prep.

 * mvme68k
	68kbug works in terms of 256 byte blocks, regardless of the
	underlying physical sector size. In most cases, there are two
	bug blocks per physical sector.

	- block 0  = The volume ID block (part of cpu_disklabel)
	- block 1  = Media configuration area (ditto)
	- block 2  = Start of first level bootstrap
	- block 31 = End of first level bootstrap
	- block 32 = FFS Superblock.

	Bug uses various parts of the first two blocks to describe the
	media, identify it as bootable and locate the start block and
	length of the first level bootstrap.

	The mvme68k MD code makes use of some of the bug-specific details
	together with most of the remaining space in the first two blocks
	to store disk geometry and partition info.

	The 2nd level bootstrap is loaded from an FFS partition using a
	list of physical sectors written at installboot(8) time. This in
	turn loads the kernel.

Cheers, Steve