encrpted lvm on a ssd

[Christian Stalp <christian.stalp@gmx.de>]

Hello out there,
one question: I have a installation on my thinkpad with an encrypted
lvm. I got this by the "guided partition" of the debian installer. I
want to recreate this on a SSD with the difference: I do not want format
the whole disk because of trimming on a SSD. I want 20% of that SSD
unformatted! And I want to use btrfs instead of ext3. So I tried to
analyse how the debian installer processed my disk and when I call
cfdisk I saw this part-table:

Name Flags Part Type FS Type [Label] Size (MB)
------------------------------------------------------------------------------
Primary Free Space 1,05*
sda1 Boot Primary ext2 254,81*
Pri/Log Free Space 1,05*
sda5 NC Logical crypto_LUKS 99773,06*
Pri/Log Free Space 0,29*

So can anybody tell me for what these gaps between the partitions are
good for? And is grub2 not able to load a kernel from a encrypted disk,
so that I still need a uncrypted boot partition?

Thanks

/christian