Handle disk sector size

[vjr]

Fixes #620

Requires pop-os/distinst#266

[vjr]

Fixes #448

[vjr]

Note to self:

Here is the command I used to launch the elementary OS live ISO and test the installer, after creating a raw format qemu disk image with qemu-img create -f raw odin.raw 20G :

qemu-system-x86_64 -machine q35,accel=kvm -m 16384 -smp 8 -cpu host -boot d -cdrom /home/vishal/Downloads/elementaryos-6.0-stable.20211005.iso -drive file=/home/vishal/Documents/QEMU/odin.raw,format=raw,id=odin,if=none -device virtio-scsi,id=scsi -device scsi-hd,bus=scsi.0,drive=odin,logical_block_size=4096,physical_block_size=4096 -bios /usr/share/qemu/OVMF.fd

I just installed the gnome-boxes deb package from the ubuntu archives which got me the required QEMU, KVM and OVMF bits.

After running the installer IIRC I just changed the -boot d option to -boot c to reboot into the installed system to see if it really worked.

[davidmhewitt]

I've imported a version of distinst with the associated fixes into the elementary PPAs, and the code looks pretty good here, just one small thing to change and then I'll test this out.

I don't like passing this sector_size through all of these layers of construction since it's just a property of the disk, not of every partition and mount, but that isn't a problem with your code, it's jut the original architecture of this, so we can sort that later.

addressed

[vjr]

@davidmhewitt @elementary/desktop-developers I've created PR pop-os/distinst#278 and along with this PR it appears to succeed installation for the 3 test cases I tried in QEMU:

1. Custom install - disk partitioned with a 500 MB EFI and the rest formated ext4 mounted on / (root)
2. Erase and install without encryption
3. Erase and install with encryption

Note that I say "appears to succeed" because the installer succeeds and partitions appear to be created fine, I've not rebooted into the installed image in QEMU to verify it works post install - would appreciate if anyone else would be able to test and comment.

In the mean time I'll try to more fully test in the coming days and report my findings here.