Intel Extensible Firmware Interface User Manual
Page 403
Protocols
— Bootable Image Support
Version 1.10
12/01/02
11-43
ReadOnly
TRUE
if the media is marked read-only otherwise,
FALSE
. This
field shows the read-only status as of the most recent
call.
WriteCaching
TRUE
if the
WriteBlocks()
function caches write data.
BlockSize
The intrinsic block size of the device. If the media changes, then
this field is updated.
IoAlign
Supplies the alignment requirement for any buffer used in a data
transfer.
IoAlign
values of 0 and 1 mean that the buffer can
be placed anywhere in memory. Otherwise,
IoAlign
must be
a power of 2, and the requirement is that the start address of a
buffer must be evenly divisible by
IoAlign
with no remainder.
LastBlock
The last logical block address on the device. If the media
changes, then this field is updated.
Description
The
LogicalPartition
is
TRUE
if the device handle is for a partition. For media that have
only one partition, the value will always be
TRUE
. For media that have multiple partitions, this
value is
FALSE
for the handle that accesses the entire device. The firmware is responsible for
adding device handles for each partition on such media.
The firmware is responsible for adding an
interface in the system. The
EFI_DISK_IO
interface allows byte-level access to devices.