[block] Replace gPXE block-device API with an iPXE asynchronous interface
The block device interface used in gPXE predates the invention of even
the old gPXE data-transfer interface, let alone the current iPXE
generic asynchronous interface mechanism. Bring this old code up to
date, with the following benefits:
o Block device commands can be cancelled by the requestor. The INT 13
layer uses this to provide a global timeout on all INT 13 calls,
with the result that an unexpected passive failure mode (such as
an iSCSI target ACKing the request but never sending a response)
will lead to a timeout that gets reported back to the INT 13 user,
rather than simply freezing the system.
o INT 13,00 (reset drive) is now able to reset the underlying block
device. INT 13 users, such as DOS, that use INT 13,00 as a method
for error recovery now have a chance of recovering.
o All block device commands are tagged, with a numerical tag that
will show up in debugging output and in packet captures; this will
allow easier interpretation of bug reports that include both
sources of information.
o The extremely ugly hacks used to generate the boot firmware tables
have been eradicated and replaced with a generic acpi_describe()
method (exploiting the ability of iPXE interfaces to pass through
methods to an underlying interface). The ACPI tables are now
built in a shared data block within .bss16, rather than each
requiring dedicated space in .data16.
o The architecture-independent concept of a SAN device has been
exposed to the iPXE core through the sanboot API, which provides
calls to hook, unhook, boot, and describe SAN devices. This
allows for much more flexible usage patterns (such as hooking an
empty SAN device and then running an OS installer via TFTP).
Signed-off-by: Michael Brown <mcb30@ipxe.org>
Access to the gpxe.org and etherboot.org domains and associated
resources has been revoked by the registrant of the domain. Work
around this problem by renaming project from gPXE to iPXE, and
updating URLs to match.
Also update README, LOG and COPYRIGHTS to remove obsolete information.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
Strip down i386 PCI configuration space I/O to the bare minimum. A
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.)
Michael Brown