UEFI and Grub2 support

Overview

OpenSolaris installs and boots off disks that are up to 2TiB in size.  While disks bigger than these can be used, they are truncated to 2TiB.  In order support disks greater than 2TiB,  UEFI specification needs to be implemented.  This impacts the boot loader, the kernel I/O framework and utilities.  Installers needed to be enhanced to support installs to these large devices.  The tasks listed here are the changes and dependencies for the installers.

Background

The UEFI specification defined a new disk label format called Guid Partition Table or GPT. GPT specification allows one to partition a disk into a large number "slices".  However in OpenSolaris, only 7 (0-6) slices are supported.  For SPARC users, this will be similar to  SMI label with slices, except with 7 instead of 8.  For x86 users, asignificant difference is that MBR based partitions will not exist.  MBR labeling  divided the disk into primary and extended partitions.   OpenSolaris  installed a VTOC into one of these partitions.  This two level indirection will disappear and  a disk will simply appear with 7 slices.  Another change for x86 users will be the introduction of  GRUB2 since GRUB is not capable of accessing devices beyond 2TiB. GRUB2 is capable of supporting MBR labels as well.

For OpenSolaris,In order  to provide a consistent user experience, GPT labels will only applied if the disk is greater than 2 TiB.

Installer Task List

Install needs to implement changes to detect and set GPT partitions, detect and set the correct bootloader when crossing the GRUB, GRUB2 boundary.  The installers also need to set a the boot bootdevice for UEFI.  The changes to support this affect all the installers as well as beadm and libti.  The text and GUI installers will need to be enhanced to display the GPT slices.