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).
typical build will now include 880 bytes of PCI support code, compared to
2327 bytes in Etherboot 5.4.
(There is a slight cost of around 5 extra bytes per access to a
non-constant config space address; this should be an overall win.
Driver-specific accesses will usually be to constant addresses, for
which there is no additional cost.)
Generic PCI code now handles 64-bit BARs correctly when setting
"membase"; drivers should need to call pci_bar_start() only if they want
to use BARs other than the first memory or I/O BAR.
Split rarely-used PCI functions out into pciextra.c.
Core PCI code is now 662 bytes (down from 1308 bytes in Etherboot 5.4).
284 bytes of this saving comes from the pci/pciextra split.
Cosmetic changes to lots of drivers (e.g. vendor_id->vendor in order to
match the names used in Linux).
Use .text16.data section with "aw" attributes, to avoid section type
conflicts when placing both code and data into .text16.
Add __from_{text16,data16}.
between the low half stored in the static variable rm_sp, and the high
half stored on the prot_call() stack, because:
Just using the stack would screw up when a prot_call()ed routine
executes a real_call(); it would have no way to find the current top of
the RM stack.
Extending rm_sp to rm_esp would not be safe, because the guarantee that
rm_sp must return to the correct value by the time an external
real-mode call returns applies only to %sp, not to %esp.
from protected-mode code.
Set up %ds to point to .data16 in prot_to_real, so that code specified
via REAL_EXEC() and friends can access variables in .data16.
Move most real-mode librm variables from .text16 to .data16.
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.
Michael Brown