debian-forge-composer/internal/disk/customizations.go
Christian Kellner 115c864f93 disk: define the default sector size constant
Move the `sectorSize` constant, defined in `customizations.go`
to `disk.go` as `DefaultSectorSize`. Rename current usages of
the former to the latter.
2022-02-22 19:23:41 +00:00

104 lines
2.6 KiB
Go

package disk
import (
"encoding/hex"
"io"
"math/rand"
"github.com/google/uuid"
"github.com/osbuild/osbuild-composer/internal/blueprint"
)
const (
BIOSBootPartitionGUID = "21686148-6449-6E6F-744E-656564454649"
BIOSBootPartitionUUID = "FAC7F1FB-3E8D-4137-A512-961DE09A5549"
FilesystemDataGUID = "0FC63DAF-8483-4772-8E79-3D69D8477DE4"
FilesystemDataUUID = "CB07C243-BC44-4717-853E-28852021225B"
EFISystemPartitionGUID = "C12A7328-F81F-11D2-BA4B-00A0C93EC93B"
EFISystemPartitionUUID = "68B2905B-DF3E-4FB3-80FA-49D1E773AA33"
EFIFilesystemUUID = "7B77-95E7"
RootPartitionUUID = "6264D520-3FB9-423F-8AB8-7A0A8E3D3562"
)
func CreatePartitionTable(
mountpoints []blueprint.FilesystemCustomization,
imageSize uint64,
basePartitionTable *PartitionTable,
rng *rand.Rand,
) (PartitionTable, error) {
// we are modifying the contents of the base partition table,
// including the file systems, which are shared among shallow
// copies of the partition table, so make a copy first
table := basePartitionTable.Clone()
for _, m := range mountpoints {
partitionSize := m.MinSize / DefaultSectorSize
if m.Mountpoint != "/" {
table.createFilesystem(m.Mountpoint, partitionSize)
}
}
if tableSize := table.getPartitionTableSize(); imageSize < tableSize {
imageSize = tableSize
}
table.Size = imageSize
// start point for all of the arches is
// 2048 sectors.
var start uint64 = table.updatePartitionStartPointOffsets(2048)
// treat the root partition as a special case
// by setting the size dynamically
rootPartition := table.RootPartition()
rootPartition.Size = ((imageSize / DefaultSectorSize) - start - 100)
// Generate new UUIDs for filesystems and partitions
table.GenerateUUIDs(rng)
return *table, nil
}
func (pt *PartitionTable) createFilesystem(mountpoint string, size uint64) {
filesystem := Filesystem{
Type: "xfs",
Mountpoint: mountpoint,
FSTabOptions: "defaults",
FSTabFreq: 0,
FSTabPassNo: 0,
}
partition := Partition{
Size: size,
Filesystem: &filesystem,
}
if pt.Type == "gpt" {
partition.Type = FilesystemDataGUID
}
pt.Partitions = append(pt.Partitions, partition)
}
func newRandomUUIDFromReader(r io.Reader) (uuid.UUID, error) {
var id uuid.UUID
_, err := io.ReadFull(r, id[:])
if err != nil {
return uuid.Nil, err
}
id[6] = (id[6] & 0x0f) | 0x40 // Version 4
id[8] = (id[8] & 0x3f) | 0x80 // Variant is 10
return id, nil
}
// NewRandomVolIDFromReader creates a random 32 bit hex string to use as a
// volume ID for FAT filesystems
func NewRandomVolIDFromReader(r io.Reader) (string, error) {
volid := make([]byte, 4)
_, err := r.Read(volid)
return hex.EncodeToString(volid), err
}