Linux IA-64 kernel and GNU Parted both support GPT (Score 3)

As author of both the Linux IA-64 kernel patch to add GPT support, and of the GNU Parted GPT patch, it's appropriate for me to comment.

Intel's Extensible Firmware Interface specification contains the spec for GPT. All systems incorporating EFI (currently, this is only IA-64 systems) need use GPT, for others it is optional.

I wrote the Linux IA-64 kernel GPT support, and it has been included in the IA-64 kernel port since September 2000. It allows use of either MBR-style or GPT-style partition records per disk. With minor tweaking, it could be used on Linux IA-32, but it is not currently.

Boot loaders such as LILO remain unaffected. LILO takes a file system location (i.e. /boot/vmlinuz), from which it asks the kernel for the physical location of that file on the disk (i.e. where in /dev/sda is the file?). The file location is entirely independent of the partitioning strategy, thus LILO works with both MBR-style and GPT-style partitioning. Linux IA-64 uses its own boot loader (elilo.efi) which again does not need to be aware of the partitioning strategy of a given disk.

Partitioning tools such as fdisk and GNU Parted need to become GPT-aware. I have created a patch for GNU Parted and have made it available to the IA-64 distributions. It could use a bit of cleanup, but is quite functional. I don't believe that anyone has written GPT support into fdisk, and would encourage anyone who wishes to please do so.

I've also written a new Linux IA-64 application "efibootmgr" which manages the EFI Boot Manager options (as defined in the EFI spec above). This tool is both MBR and GPT-aware, and allows for booting your OS off of any disk/partition in your system provided the partition contains a FAT-12,-16, or -32 file system. Additional work will go into EFI in the future to add ext2 file system awareness to avoid even this restriction.

All of these topics have been discussed on the Linux IA-64 developer mailing list. If you care to join the Linux IA-64 developer community, please see www.linuxia64.org.