GPT
GPT stands for GUID Partition Table. It is made to replace MBR partitioning.
Layout
| LBA 0 | Protective Master Boot Record (PMBR). Holds a partition pointing to GPT to avoid accidental overwrite by old programs. |
| LBA 1 | partition header, can be identified by 8 bytes magic "EFI PART" (45h 46h 49h 20h 50h 41h 52h 54h) |
| LBA 2..33 | partition table entires |
| ...data on disk... | |
| LBA -33..-2 | mirror of partition table |
| LBA -1 | mirror of partition header on last addressable sector |
Utilities
The following utilities can handle GPT:
- parted, gparted, gdisk on Linux
- diskutil on MacOSX
- diskpart on Windows (Vista and upwards)
- gpt on MacOSX and BSDs.
Boot loaders
EFI firmware is capable of booting from a specific GPT partition, EFI System Partition which is basically a FAT32 partition. It should contain a slightly modified PE-executable, like ELILO. On old machines with legacy BIOS only you can use GRUB, or you can write a custom boot code.