disk: AddPartitionsForBootMode() helper function (COMPOSER-2355)

pkg/disk/disk.go

@@ -63,6 +63,12 @@ const (
 
 	// Partition type ID for any native Linux filesystem on dos
 	DosLinuxTypeID = "83"
+
+	// Partition type ID for BIOS boot partition on dos
+	DosBIOSBootID = "ef02"
+
+	// Partition type ID for ESP on dos
+	DosESPID = "ef00"
 )
 
 // FSType is the filesystem type enum.

pkg/disk/partition_table.go

@@ -9,6 +9,7 @@ import (
 
 	"github.com/osbuild/images/pkg/blueprint"
 	"github.com/osbuild/images/pkg/datasizes"
+	"github.com/osbuild/images/pkg/platform"
 )
 
 type PartitionTable struct {
@@ -1054,3 +1055,92 @@ func EnsureBootPartition(pt *PartitionTable, bootFsType FSType) error {
 	pt.Partitions = append(pt.Partitions, bootPart)
 	return nil
 }
+
+// AddPartitionsForBootMode creates partitions to satisfy the boot mode requirements:
+//   - BIOS/legacy: adds a 1 MiB BIOS boot partition.
+//   - UEFI: adds a 200 MiB EFI system partition.
+//   - Hybrid: adds both.
+//
+// The function will append the new partitions to the end of the existing
+// partition table therefore it is best to call this function early to put them
+// near the front (as is conventional).
+func AddPartitionsForBootMode(pt *PartitionTable, bootMode platform.BootMode) error {
+	switch bootMode {
+	case platform.BOOT_LEGACY:
+		// add BIOS boot partition
+		part, err := mkBIOSBoot(pt.Type)
+		if err != nil {
+			return err
+		}
+		pt.Partitions = append(pt.Partitions, part)
+		return nil
+	case platform.BOOT_UEFI:
+		// add ESP
+		part, err := mkESP(200*datasizes.MiB, pt.Type)
+		if err != nil {
+			return err
+		}
+		pt.Partitions = append(pt.Partitions, part)
+		return nil
+	case platform.BOOT_HYBRID:
+		// add both
+		bios, err := mkBIOSBoot(pt.Type)
+		if err != nil {
+			return err
+		}
+		esp, err := mkESP(200*datasizes.MiB, pt.Type)
+		if err != nil {
+			return err
+		}
+		pt.Partitions = append(pt.Partitions, bios, esp)
+		return nil
+	case platform.BOOT_NONE:
+		return nil
+	default:
+		return fmt.Errorf("invalid boot mode specified: %s", bootMode)
+	}
+}
+
+func mkBIOSBoot(ptType string) (Partition, error) {
+	var partType string
+	switch ptType {
+	case "dos":
+		partType = DosBIOSBootID
+	case "gpt":
+		partType = BIOSBootPartitionGUID
+	default:
+		return Partition{}, fmt.Errorf("error creating BIOS boot partition: unknown or unsupported partition table type: %s", ptType)
+	}
+	return Partition{
+		Size:     1 * datasizes.MiB,
+		Bootable: true,
+		Type:     partType,
+		UUID:     BIOSBootPartitionUUID,
+	}, nil
+}
+
+func mkESP(size uint64, ptType string) (Partition, error) {
+	var partType string
+	switch ptType {
+	case "dos":
+		partType = DosESPID
+	case "gpt":
+		partType = EFISystemPartitionGUID
+	default:
+		return Partition{}, fmt.Errorf("error creating EFI system partition: unknown or unsupported partition table type: %s", ptType)
+	}
+	return Partition{
+		Size: size,
+		Type: partType,
+		UUID: EFISystemPartitionUUID,
+		Payload: &Filesystem{
+			Type:         "vfat",
+			UUID:         EFIFilesystemUUID,
+			Mountpoint:   "/boot/efi",
+			Label:        "EFI-SYSTEM",
+			FSTabOptions: "defaults,uid=0,gid=0,umask=077,shortname=winnt",
+			FSTabFreq:    0,
+			FSTabPassNo:  2,
+		},
+	}, nil
+}

pkg/disk/partition_table_test.go

@@ -9,6 +9,7 @@ import (
 	"github.com/osbuild/images/internal/testdisk"
 	"github.com/osbuild/images/pkg/datasizes"
 	"github.com/osbuild/images/pkg/disk"
+	"github.com/osbuild/images/pkg/platform"
 )
 
 func TestPartitionTable_GetMountpointSize(t *testing.T) {
@@ -1023,3 +1024,195 @@ func TestEnsureBootPartition(t *testing.T) {
 		})
 	}
 }
+
+func TestAddPartitionsForBootMode(t *testing.T) {
+	type testCase struct {
+		pt       disk.PartitionTable
+		bootMode platform.BootMode
+		expected disk.PartitionTable
+		errmsg   string
+	}
+
+	testCases := map[string]testCase{
+		// the partition table type shouldn't matter when the boot mode is
+		// none, but let's test with both anyway
+		"none-gpt": {
+			pt:       disk.PartitionTable{Type: "gpt"},
+			bootMode: platform.BOOT_NONE,
+			expected: disk.PartitionTable{Type: "gpt"},
+		},
+		"none-dos": {
+			pt:       disk.PartitionTable{Type: "dos"},
+			bootMode: platform.BOOT_NONE,
+			expected: disk.PartitionTable{Type: "dos"},
+		},
+		"bios-gpt": {
+			pt:       disk.PartitionTable{Type: "gpt"},
+			bootMode: platform.BOOT_LEGACY,
+			expected: disk.PartitionTable{
+				Type: "gpt",
+				Partitions: []disk.Partition{
+					{
+						Bootable: true,
+						Start:    0,
+						Size:     1 * datasizes.MiB,
+						Type:     disk.BIOSBootPartitionGUID,
+						UUID:     disk.BIOSBootPartitionUUID,
+					},
+				},
+			},
+		},
+		"bios-dos": {
+			pt:       disk.PartitionTable{Type: "dos"},
+			bootMode: platform.BOOT_LEGACY,
+			expected: disk.PartitionTable{
+				Type: "dos",
+				Partitions: []disk.Partition{
+					{
+						Bootable: true,
+						Start:    0,
+						Size:     1 * datasizes.MiB,
+						Type:     disk.DosBIOSBootID,
+						UUID:     disk.BIOSBootPartitionUUID,
+					},
+				},
+			},
+		},
+		"uefi-gpt": {
+			pt:       disk.PartitionTable{Type: "gpt"},
+			bootMode: platform.BOOT_UEFI,
+			expected: disk.PartitionTable{
+				Type: "gpt",
+				Partitions: []disk.Partition{
+					{
+						Start: 0 * datasizes.MiB,
+						Size:  200 * datasizes.MiB,
+						Type:  disk.EFISystemPartitionGUID,
+						UUID:  disk.EFISystemPartitionUUID,
+						Payload: &disk.Filesystem{
+							Type:         "vfat",
+							UUID:         disk.EFIFilesystemUUID,
+							Mountpoint:   "/boot/efi",
+							Label:        "EFI-SYSTEM",
+							FSTabOptions: "defaults,uid=0,gid=0,umask=077,shortname=winnt",
+							FSTabFreq:    0,
+							FSTabPassNo:  2,
+						},
+					},
+				},
+			},
+		},
+		"uefi-dos": {
+			pt:       disk.PartitionTable{Type: "dos"},
+			bootMode: platform.BOOT_UEFI,
+			expected: disk.PartitionTable{
+				Type: "dos",
+				Partitions: []disk.Partition{
+					{
+						Start: 0 * datasizes.MiB,
+						Size:  200 * datasizes.MiB,
+						Type:  disk.DosESPID,
+						UUID:  disk.EFISystemPartitionUUID,
+						Payload: &disk.Filesystem{
+							Type:         "vfat",
+							UUID:         disk.EFIFilesystemUUID,
+							Mountpoint:   "/boot/efi",
+							Label:        "EFI-SYSTEM",
+							FSTabOptions: "defaults,uid=0,gid=0,umask=077,shortname=winnt",
+							FSTabFreq:    0,
+							FSTabPassNo:  2,
+						},
+					},
+				},
+			},
+		},
+		"hybrid-gpt": {
+			pt:       disk.PartitionTable{Type: "gpt"},
+			bootMode: platform.BOOT_HYBRID,
+			expected: disk.PartitionTable{
+				Type: "gpt",
+				Partitions: []disk.Partition{
+					{
+						Size:     1 * datasizes.MiB,
+						Bootable: true,
+						Type:     disk.BIOSBootPartitionGUID,
+						UUID:     disk.BIOSBootPartitionUUID,
+					},
+					{
+						Size: 200 * datasizes.MiB,
+						Type: disk.EFISystemPartitionGUID,
+						UUID: disk.EFISystemPartitionUUID,
+						Payload: &disk.Filesystem{
+							Type:         "vfat",
+							UUID:         disk.EFIFilesystemUUID,
+							Mountpoint:   "/boot/efi",
+							Label:        "EFI-SYSTEM",
+							FSTabOptions: "defaults,uid=0,gid=0,umask=077,shortname=winnt",
+							FSTabFreq:    0,
+							FSTabPassNo:  2,
+						},
+					},
+				},
+			},
+		},
+		"hybrid-dos": {
+			pt:       disk.PartitionTable{Type: "dos"},
+			bootMode: platform.BOOT_HYBRID,
+			expected: disk.PartitionTable{
+				Type: "dos",
+				Partitions: []disk.Partition{
+					{
+						Size:     1 * datasizes.MiB,
+						Bootable: true,
+						Type:     disk.DosBIOSBootID,
+						UUID:     disk.BIOSBootPartitionUUID,
+					},
+					{
+						Size: 200 * datasizes.MiB,
+						Type: disk.DosESPID,
+						UUID: disk.EFISystemPartitionUUID,
+						Payload: &disk.Filesystem{
+							Type:         "vfat",
+							UUID:         disk.EFIFilesystemUUID,
+							Mountpoint:   "/boot/efi",
+							Label:        "EFI-SYSTEM",
+							FSTabOptions: "defaults,uid=0,gid=0,umask=077,shortname=winnt",
+							FSTabFreq:    0,
+							FSTabPassNo:  2,
+						},
+					},
+				},
+			},
+		},
+		"bad-pttype-bios": {
+			pt:       disk.PartitionTable{Type: "super-gpt"},
+			bootMode: platform.BOOT_LEGACY,
+			errmsg:   "error creating BIOS boot partition: unknown or unsupported partition table type: super-gpt",
+		},
+		"bad-pttype-uefi": {
+			pt:       disk.PartitionTable{Type: "super-gpt"},
+			bootMode: platform.BOOT_UEFI,
+			errmsg:   "error creating EFI system partition: unknown or unsupported partition table type: super-gpt",
+		},
+		"bad-pttype-hybrid": {
+			pt:       disk.PartitionTable{Type: "super-gpt"},
+			bootMode: platform.BOOT_HYBRID,
+			errmsg:   "error creating BIOS boot partition: unknown or unsupported partition table type: super-gpt",
+		},
+	}
+
+	for name := range testCases {
+		tc := testCases[name]
+		t.Run(name, func(t *testing.T) {
+			assert := assert.New(t)
+			pt := tc.pt
+			err := disk.AddPartitionsForBootMode(&pt, tc.bootMode)
+			if tc.errmsg == "" {
+				assert.NoError(err)
+				assert.Equal(tc.expected, pt)
+			} else {
+				assert.EqualError(err, tc.errmsg)
+			}
+		})
+	}
+}