Add the concept of a "user pointer" (similar to the void __user * in
the kernel), which encapsulates the information needed to refer to an
external buffer. Under normal operation, this can just be a void *
equivalent, but under -DKEEP_IT_REAL it would be a segoff_t equivalent.
Use this concept to avoid the need for bounce buffers in int13.c,
which reduces memory usage and opens up the possibility of using
multi-sector reads.
Extend the block-device API and the SCSI block device implementation
to support multi-sector reads.
Update iscsi.c to use user buffers.
Move the obsolete portions of realmode.h to old_realmode.h.
MS-DOS now boots an order of magnitude faster over iSCSI (~10 seconds
from power-up to C:> prompt in bochs).
iSCSI writes seem to be working (at least, the ethereal trace shows no
errors; still need to verify data integrity).
SCSI response PDUs are handled: status and sense data (if available) are
returned via the scsi_command structure.
Updated iSCSI session parameter usage.
I want to get to the point where any header in include/ reflects a
standard user-level header (e.g. a POSIX header), while everything that's
specific to gPXE lives in include/gpxe/. Headers that reflect a Linux
header (e.g. if_ether.h) should also be in include/gpxe/, with the same
name as the Linux header and, preferably, the same names used for the
definitions.