Fix partition layout (#794)

* Fix partition layout

* Tweaked the numbers to match the alignment of previous partitions.

Co-authored-by: Anton Hvornum <anton.feeds@gmail.com>

2 files changed, 46 insertions, 17 deletions

diff --git a/archinstall/lib/disk/user_guides.py b/archinstall/lib/disk/user_guides.py
index b0a8fe8a..a90ac506 100644
--- a/archinstall/lib/disk/user_guides.py
+++ b/archinstall/lib/disk/user_guides.py
@@ -6,6 +6,7 @@ if TYPE_CHECKING:
 	from .blockdevice import BlockDevice
 
 from .helpers import sort_block_devices_based_on_performance, select_largest_device, select_disk_larger_than_or_close_to
+from ..hardware import has_uefi
 from ..output import log
 
 def suggest_single_disk_layout(block_device :BlockDevice,
@@ -16,7 +17,7 @@ def suggest_single_disk_layout(block_device :BlockDevice,
 		from ..user_interaction import ask_for_main_filesystem_format
 		default_filesystem = ask_for_main_filesystem_format(advanced_options)
 
-	MIN_SIZE_TO_ALLOW_HOME_PART = 40 # Gb
+	MIN_SIZE_TO_ALLOW_HOME_PART = 40 # GiB
 	using_subvolumes = False
 	using_home_partition = False
 
@@ -30,11 +31,19 @@ def suggest_single_disk_layout(block_device :BlockDevice,
 		}
 	}
 
+	# Used for reference: https://wiki.archlinux.org/title/partitioning
+
+	# 2 MiB is unallocated for GRUB on BIOS. Potentially unneeded for
+	# other bootloaders?
+
+	# TODO: On BIOS, /boot partition is only needed if the drive will
+	# be encrypted, otherwise it is not recommended. We should probably
+	# add a check for whether the drive will be encrypted or not.
 	layout[block_device.path]['partitions'].append({
 		# Boot
 		"type" : "primary",
-		"start" : "5MB",
-		"size" : "513MB",
+		"start" : "3MiB",
+		"size" : "203MiB",
 		"boot" : True,
 		"encrypted" : False,
 		"format" : True,
@@ -43,10 +52,18 @@ def suggest_single_disk_layout(block_device :BlockDevice,
 			"format" : "fat32"
 		}
 	})
+
+	# Increase the UEFI partition if UEFI is detected.
+	# Also re-align the start to 1MiB since we don't need the first sectors
+	# like we do in MBR layouts where the boot loader is installed traditionally.
+	if has_uefi():
+		layout[block_device.path]['partitions'][-1]['start'] = '1MiB'
+		layout[block_device.path]['partitions'][-1]['size'] = '512MiB'
+
 	layout[block_device.path]['partitions'].append({
 		# Root
 		"type" : "primary",
-		"start" : "518MB",
+		"start" : "206MiB",
 		"encrypted" : False,
 		"format" : True,
 		"mountpoint" : "/",
@@ -55,6 +72,9 @@ def suggest_single_disk_layout(block_device :BlockDevice,
 		}
 	})
 
+	if has_uefi():
+		layout[block_device.path]['partitions'][-1]['start'] = '513MiB'
+
 	if not using_subvolumes and block_device.size >= MIN_SIZE_TO_ALLOW_HOME_PART:
 		using_home_partition = input('Would you like to create a separate partition for /home? (Y/n): ').strip().lower() in ('', 'y', 'yes')
 
@@ -65,7 +85,7 @@ def suggest_single_disk_layout(block_device :BlockDevice,
 		# Or the user doesn't want to create a separate partition for /home
 		layout[block_device.path]['partitions'][-1]['size'] = '100%'
 	else:
-		layout[block_device.path]['partitions'][-1]['size'] = f"{min(block_device.size, 20)}GB"
+		layout[block_device.path]['partitions'][-1]['size'] = f"{min(block_device.size, 20)}GiB"
 
 	if default_filesystem == 'btrfs' and using_subvolumes:
 		# if input('Do you want to use a recommended structure? (Y/n): ').strip().lower() in ('', 'y', 'yes'):
@@ -90,10 +110,10 @@ def suggest_single_disk_layout(block_device :BlockDevice,
 		layout[block_device.path]['partitions'].append({
 			# Home
 			"type" : "primary",
+			"start" : f"{min(block_device.size, 20)}GiB",
+			"size" : "100%",
 			"encrypted" : False,
 			"format" : True,
-			"start" : f"{min(block_device.size+0.5, 20.5)}GB",
-			"size" : "100%",
 			"mountpoint" : "/home",
 			"filesystem" : {
 				"format" : default_filesystem
@@ -115,8 +135,8 @@ def suggest_multi_disk_layout(block_devices :List[BlockDevice],
 	# https://www.reddit.com/r/btrfs/comments/m287gp/partition_strategy_for_two_physical_disks/
 	# https://www.reddit.com/r/btrfs/comments/9us4hr/what_is_your_btrfs_partitionsubvolumes_scheme/
 
-	MIN_SIZE_TO_ALLOW_HOME_PART = 40 # Gb
-	ARCH_LINUX_INSTALLED_SIZE = 20 # Gb, rough estimate taking in to account user desktops etc. TODO: Catch user packages to detect size?
+	MIN_SIZE_TO_ALLOW_HOME_PART = 40 # GiB
+	ARCH_LINUX_INSTALLED_SIZE = 20 # GiB, rough estimate taking in to account user desktops etc. TODO: Catch user packages to detect size?
 
 	block_devices = sort_block_devices_based_on_performance(block_devices).keys()
 
@@ -136,11 +156,13 @@ def suggest_multi_disk_layout(block_devices :List[BlockDevice],
 		},
 	}
 
+	# TODO: Same deal as with the single disk layout, we should
+	# probably check if the drive will be encrypted.
 	layout[root_device.path]['partitions'].append({
 		# Boot
 		"type" : "primary",
-		"start" : "5MB",
-		"size" : "513MB",
+		"start" : "3MiB",
+		"size" : "203MiB",
 		"boot" : True,
 		"encrypted" : False,
 		"format" : True,
@@ -149,26 +171,33 @@ def suggest_multi_disk_layout(block_devices :List[BlockDevice],
 			"format" : "fat32"
 		}
 	})
+
+	if has_uefi():
+		layout[root_device.path]['partitions'][-1]['start'] = '1MiB'
+		layout[root_device.path]['partitions'][-1]['size'] = '512MiB'
+
 	layout[root_device.path]['partitions'].append({
 		# Root
 		"type" : "primary",
-		"start" : "518MB",
+		"start" : "206MiB",
+		"size" : "100%",
 		"encrypted" : False,
 		"format" : True,
-		"size" : "100%",
 		"mountpoint" : "/",
 		"filesystem" : {
 			"format" : default_filesystem
 		}
 	})
+	if has_uefi():
+		layout[root_device.path]['partitions'][-1]['start'] = '513MiB'
 
 	layout[home_device.path]['partitions'].append({
 		# Home
 		"type" : "primary",
+		"start" : "1MiB",
+		"size" : "100%",
 		"encrypted" : False,
 		"format" : True,
-		"start" : "5MB",
-		"size" : "100%",
 		"mountpoint" : "/home",
 		"filesystem" : {
 			"format" : default_filesystem
diff --git a/examples/guided.py b/examples/guided.py
index 0760baf1..e8a1f4df 100644
--- a/examples/guided.py
+++ b/examples/guided.py
@@ -255,8 +255,8 @@ def perform_installation(mountpoint):
 		# Placing /boot check during installation because this will catch both re-use and wipe scenarios.
 		for partition in installation.partitions:
 			if partition.mountpoint == installation.target + '/boot':
-				if partition.size <= 0.25: # in GB
-					raise archinstall.DiskError(f"The selected /boot partition in use is not large enough to properly install a boot loader. Please resize it to at least 256MB and re-run the installation.")
+				if partition.size < 0.19: # ~200 MiB in GiB
+					raise archinstall.DiskError(f"The selected /boot partition in use is not large enough to properly install a boot loader. Please resize it to at least 200MiB and re-run the installation.")
 
 		# if len(mirrors):
 		# Certain services might be running that affects the system during installation.