Details on blocklist in stage2/1_5

[Jason Ivey]

I am trying to find some information on the block list contained at the end of the first sector in stage2.  I am an engineer at PowerQuest and were working on adding support for GRUB into PartitionMagic.  >From the documentation I have noted most of the fields we need to update in stage1, stage1_5 and stage2 but I’m stuck on the block list that describes the locations of stage2.  From what I can tell from the code is that it is an 8 byte structure.  The first 4 bytes is the sector address from the beginning of the disk of the next run of sectors.  The next 2 bytes appear to be the number of sectors in that run.  But the last 2 bytes as the code describes it is some corrected address.  Could I get a small description of this block list and anything you might see as things to watch out for if we move/resize a partition that has GRUB installed on it?

 

Thank you,

 

Jason Ivey

PowerQuest Corp.