zpool create should support efi system partition
Since we support whole-disk configuration for boot pool, we also will need whole disk support with UEFI boot and for this, zpool create should create efi-system partition.
I have borrowed the idea from oracle solaris, and introducing zpool create -B switch to provide an way to specify that boot partition should be created. However, there is still an question, how big should the system partition be.
For time being, I have set default size 256MB (thats minimum size for FAT32 with 4k blocks). To support custom size, the set on creation "bootsize" property is created and so the custom size can be set as: zpool create
B -o bootsize=34MB rpool c0t0d0'. Older zfs/zpool implementations are ignoring this property.
After pool is created, the "bootsize" property is read only. When -B switch is not used, the bootsize defaults to 0 and is shown in zpool get output with value '