11.3 How to specify block lists
A block list is used for specifying a file that doesn't appear in the
filesystem, like a chainloader. The syntax is
Here is an example:
This represents that GRUB should read blocks 0 through 99, block 200,
and blocks 300 through 599. If you omit an offset, then GRUB assumes
the offset is zero.
Like the file name syntax (see File name syntax), if a blocklist
does not contain a device name, then GRUB uses GRUB's root
(hd0,1)+1 is the same as
+1 when the root
device is `(hd0,1)'.