Manually choose partitions

[gazorby]

A small rework of partitioning part to allow installing without clearing partition table

Four new global variables are introduced :

ERASE="false"  # If true, partitions will be automatically created

PARTITION_BIOS=""  # let this empty if you have an EFI system
PARTITION_BOOT=""
PARTITION_ROOT="" 

When setting ERASE to false, DEVICE variable is ignored, otherwise, PARTITION_BIOS, PARTITION_BOOT and PARTITION_ROOT are ignored.

check_variables() has also been updated to ensure PARTITION_BIOS is correctly set on BIOS system.

Moreover, i upadated encrypt options to use aes-xts-plain64 cipher (based on cryptsetup benchmark) and --align-payload=8192 option (based on this explanation)

[picodotdev]

Hi Gazorby, I created #76 to allow custom partition to be based on your pull request, that I think will allow to delegate to alis the creation of the partitions (with a option manual to only use existing partitions, this would be the case of your PR, the options custom will allow to avoid clear the partition table) but at the same time use a custom partition scheme. This is for avoid to be the user to do manually and before alis execution the partition.

For the other changes, this is info that gives my system that I created without specifying -c aes-xts-plain64. The value xts-plain64 is different than aes-xts-plain64?.

sudo cryptsetup luksDump /dev/nvme0n1p2 |grep -e "mode" -e "Payload" -e "MK bits"
[sudo] password for picodotdev: 
Cipher mode:   	xts-plain64
Payload offset:	4096
MK bits:       	512

For --align-payload=8192 I dont know if this is also different from default values, the explanation link dates from 2010, I dont know if this has changed from then.

Is there in the Arch Linux wiki about this?
Also I dont know if this is done automatic as the following comment.

(cryptsetup will get support for automatic alignment according
to kernel exported device parameters soon, so all this will be automatic)

[picodotdev]

I uploaded a branch with a initial implementation for this, I dont tested yet.

-c aes-xts-plain64 and --align-payload=8192 yet no.

[picodotdev]

-c aes-xts-plain64 and --align-payload=8192 yet no implemented, I am not completely sure they are necessary and good recommendation.