Minimise code size by forcing the use of memory addresses for
__bswap_16s() and __bswap_64s(). (__bswap_32s() cannot avoid loading the
value into a register.)
Signed-off-by: Michael Brown <mcb30@ipxe.org>
Fix a strict-aliasing error on certain versions of gcc.
Reported-by: Marko Myllynen <myllynen@redhat.com>
Signed-off-by: Michael Brown <mcb30@ipxe.org>
Replace SHA-1 implementation from AXTLS with a dedicated iPXE
implementation which is around 40% smaller. This implementation has
been verified using the existing SHA-1 self-tests (including the NIST
SHA-1 test vectors).
Signed-off-by: Michael Brown <mcb30@ipxe.org>
Use the "bswap" instruction to shrink the size of byte-swapping code,
and provide the in-place variants __bswap_{16,32,64}s.
"bswap" is available only on 486 and later processors. (We already
assume the presence of "cpuid" and "rdtsc", which are available only
on Pentium and later processors.)
Signed-off-by: Michael Brown <mcb30@ipxe.org>
Advertise support for TLS version 1.1, and be prepared to downgrade to
TLS version 1.0. Tested against Apache with mod_gnutls, using the
GnuTLSPriorities directive to force specific protocol versions.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
Allow packet transmission to be deferred pending successful ARP
resolution. This avoids the time spent waiting for a higher-level
protocol (e.g. TCP or TFTP) to attempt retransmission.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
Some PXE stacks (observed with a QLogic 8242) will always try to
prepend a link-layer header, even if the caller uses P_UNKNOWN to
indicate that the link-layer header has already been filled in. This
results in an invalid packet being transmitted.
Work around these faulty PXE stacks where possible by stripping the
existing link-layer header and allowing the PXE stack to (re)construct
the link-layer header itself.
Originally-fixed-by: Buck Huppmann <buckh@pobox.com>
Signed-off-by: Michael Brown <mcb30@ipxe.org>
Some iSCSI targets respond to a PDU before receiving the padding
bytes. If the target responds quickly enough, this can cause iPXE to
start processing a new TX PDU before the padding bytes have been sent,
which results in a protocol violation.
Fix by always transmitting the padding bytes along with the data
segment.
Originally-fixed-by: Shyam Iyer <shyam_iyer@dell.com>
Signed-off-by: Michael Brown <mcb30@ipxe.org>
As RFC 2616 10.3.4 explains, a 303 status is the proper HTTP 1.1
behavior for what most HTTP 1.0 clients did with code 302.
Signed-off-by: Jason Lunz <lunz@acm.org>
Signed-off-by: Michael Brown <mcb30@ipxe.org>
Abstract out the generic line-handling portions of the syslog
putchar() routine, to allow use by other console types.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
Explicitly disable the syslog console when no syslog server is
defined, rather than (ab)using the socket family address as an
equivalent console-enabled flag.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
Separate out the core HTTP functionality (which is shared by both HTTP
and HTTPS) from the provision of the "http://" URI opener. This
allows for builds that support only "https://" URIs.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
The RTC-based entropy source uses the nanosecond-scale CPU TSC to
measure the time between two 1kHz interrupts generated by the CMOS
RTC. In a physical machine these clocks are driven from independent
crystals, resulting in some observable clock drift. In a virtual
machine, the CMOS RTC is typically emulated using host-OS
constructions such as SIGALRM.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
Separate out the list of self-tests from the self-test infrastructure.
This allows tests to be run individually. For example:
make bin/sha1_test.iso
Signed-off-by: Michael Brown <mcb30@ipxe.org>
RSA requires the generation of random non-zero bytes (i.e. a sequence
of random numbers in the range [0x01,0xff]). ANS X9.82 provides
various Approved methods for converting random bits into random
numbers. The simplest such method is the Simple Discard Method.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
ANS X9.82 specifies that the start-up tests shall consist of at least
one full cycle of the continuous tests.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
ANS X9.82 specifies several Approved Sources of Entropy Input (SEI).
One such SEI uses an entropy source as the Source of Entropy Input,
condensing each entropy source output after each GetEntropy call.
This can be implemented relatively cheaply in iPXE and avoids the need
to allocate potentially very large buffers.
(Note that the terms "entropy source" and "Source of Entropy Input"
are not synonyms within the context of ANS X9.82.)
Use the iPXE API mechanism to allow entropy sources to be selected at
compilation time.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
Treat an empty (zeroed) DRBG as invalid. This ensures that a DRBG
that has not yet been instantiated (or that has been uninstantiated)
will refuse to attempt to generate random bits.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
NIST provides a set of known-answer tests for the Hash_DRBG algorithm,
which includes known answers for the derivation function Hash_df used
as part of Hash_DRBG. Hash_DRBG is not an Approved algorithm for ANS
X9.82, but the known answers for Hash_df (which is part of ANS X9.82)
can still be used as part of the conformance testing for ANS X9.82.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
ANS X9.82 specifies several Approved derivation functions for use in
distributing entropy throughout a buffer. One such derivation
function is Hash_df, which can be implemented using the existing iPXE
SHA-1 functionality.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
iPXE exposes some extended capabilities via the PXE FILE API to allow
NBPs such as pxelinux to use protocols other than TFTP. Provide an
equivalent interface as a UEFI protocol so that EFI binaries may also
take advantage of iPXE's extended capabilities.
This can be used with a patched version of elilo, for example:
http://comments.gmane.org/gmane.comp.boot-loaders.elilo.general/147
Signed-off-by: Michael Brown <mcb30@ipxe.org>
Practically speaking, it seems the convention is to only have one
packet pending and not rely upon any mechanism to associate returned
txbuf with txqueue.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
This function never did much in this driver anyway, and after commit
b5ed30b2 ("[tg3] Fix compilation on newer gcc versions") it became
apparent that its remaining functionality could be easily moved to
tg3_test_dma().
Signed-off-by: Thomas Miletich <thomas.miletich@gmail.com>
Signed-off-by: Michael Brown <mcb30@ipxe.org>
initrd_init() calls umalloc() to allocate space for the initrd image,
but does so before hide_etherboot() has been called. It is therefore
possible for the initrd to end up overwriting iPXE itself.
Fix by converting initrd_init() from an init_fn to a startup_fn.
Originally-fixed-by: Till Straumann <strauman@slac.stanford.edu>
Signed-off-by: Michael Brown <mcb30@ipxe.org>
Replace the old Etherboot tg3 driver with a more up-to-date driver
using the iPXE API.
Signed-off-by: Thomas Miletich <thomas.miletich@gmail.com>
Modified-by: Michael Brown <mcb30@ipxe.org>
Signed-off-by: Michael Brown <mcb30@ipxe.org>
ANS X9.82 specifies that an Approved DRBG must consist of an Approved
algorithm wrapped inside an envelope which handles entropy gathering,
prediction resistance, automatic reseeding and other housekeeping
tasks.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
Cryptographic random number generation requires an entropy source,
which is used as the input to a Deterministic Random Bit Generator
(DRBG).
iPXE does not currently have a suitable entropy source. Provide a
dummy source to allow the DRBG code to be implemented.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
NIST provides a set of known-answer tests for the HMAC_DRBG algorithm,
which can be used as part of the conformance testing for ANS X9.82.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
ANS X9.82 specifies several Approved algorithms for use in a
Deterministic Random Bit Generator (DRBG). One such algorithm is
HMAC_DRBG, which can be implemented using the existing iPXE SHA-1 and
HMAC functionality. This algorithm provides a maximum security
strength of 128 bits.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
The command line may be situated in an area of base memory that will
be overwritten by iPXE's real-mode segments, causing the command line
to be corrupted before it can be used.
Fix by creating a copy of the command line on the prefix stack (below
0x7c00) before installing the real-mode segments.
Reported-by: Dave Hansen <dave@sr71.net>
Signed-off-by: Michael Brown <mcb30@ipxe.org>
PXENV_FILE_EXIT_HOOK is designed to allow ipxelinux.0 to unload both
the iPXE and pxelinux components without affecting the underlying PXE
stack. Unfortunately, it causes unexpected behaviour in other
situations, such as when loading a non-embedded pxelinux.0 via
undionly.kpxe. For example:
PXE ROM -> undionly.kpxe -> pxelinux.0 -> chain.c32 to boot hd0
would cause control to return to iPXE instead of booting from the hard
disk. In some cases, this would result in a harmless but confusing
"No more network devices" message; in other cases stranger things
would happen, such as being returned to the iPXE shell prompt.
The fundamental problem is that when pxelinux detects
PXENV_FILE_EXIT_HOOK, it may attempt to specify an exit hook and then
exit back to iPXE, assuming that iPXE will in turn exit cleanly via
the specified exit hook. This is not a valid assumption in the
general case, since the action of exiting back to iPXE does not
directly cause iPXE to exit itself. (In the specific case of
ipxelinux.0, this will work since the embedded script exits as soon as
pxelinux.0 exits.)
Fix the unexpected behaviour in the non-ipxelinux.0 cases by including
support for PXENV_FILE_EXIT_HOOK only when using a new .kkkpxe format.
The ipxelinux.0 build process should therefore now use undionly.kkkpxe
instead of undionly.kkpxe.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
Very nasty things can happen if a NULL network device is used. Check
that pxe_netdev is non-NULL at the applicable entry points, so that
this type of problem gets reported to the caller rather than being
allowed to crash the system.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
It can sometimes be awkward to prevent additional packets from being
received during a loopback test. Allow such additional packets to be
present without terminating the test.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
On at least one PXE stack (Realtek r8169), PXENV_UNDI_INITIALIZE has
been observed to fail intermittently due to a media test failure (PXE
error 0x00000061). Retrying the call to PXENV_UNDI_INITIALIZE
succeeds, and the NIC is then usable.
It is worth noting that this particular Realtek PXE stack is already
known to be unreliable: for example, it repeatably fails its own
boot-time media test after every warm reboot.
Fix by attempting PXENV_UNDI_INITIALIZE multiple times, with a short
delay between each attempt to allow the link to settle.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
The PXE specification requires us to request DHCP options 128 to 135
inclusive, although these have no defined purpose.
Suggested-by: Ralf Buettner <rab@bootix.com>
Signed-off-by: Michael Brown <mcb30@ipxe.org>
The RS bit is used to instruct the NIC to update the TX descriptor
status byte. The RPS bit is used to instruct the NIC to defer this
update until after the packet has been transmitted on the wire (rather
than merely read into the transmit FIFO).
The driver currently sets RPS but not RS. Some e1000 models seem to
interpret this as implying that the status byte should be updated;
some don't. On the ones that don't, we never see any TX completions
and so rapidly run out of TX buffers.
Fix by setting the RS bit in the TX descriptor. (We don't care about
when the packet reaches the wire, so don't bother setting the RPS
bit.)
Reported-by: Miroslav Halas <miroslav.halas@bankofamerica.com>
Signed-off-by: Michael Brown <mcb30@ipxe.org>
Some iSCSI targets (observed with stgt) can be configured to reject
connections that do not use header or data digests, and will respond
with "HeaderDigest=Reject" and/or "DataDigest=Reject", while still
allowing the connection to proceed to the full feature phase.
According to a strict reading of RFC3720, we are perfectly safe to
ignore these "Reject" messages: upon such a rejection "the negotiated
key is left at its current value (or default if no value was set)".
Since the default value for both HeaderDigest and DataDigest is
"None", then the only viable conclusion to be drawn is that the value
resulting from "Reject" is still "None".
Unfortunately, stgt doesn't seem to agree with this interpretation of
events, causing us to eventually report an unhelpful "connection timed
out" message to the user when we don't get any response to our first
PDU in full feature phase.
Fix by detecting any rejected parameters and immediately reporting an
error, which at least gives the user some insight as to what the real
problem may be.
Reported-by: Michal Suchanek <hramrach@centrum.cz>
Tested-by: Michal Suchanek <hramrach@centrum.cz>
Signed-off-by: Michael Brown <mcb30@ipxe.org>
Commit 9b99d2a ("[build] Avoid generating ROMs with "match-any" vendor
or device IDs") introduced a regression which caused the UNDI PCI
driver to be omitted from the list of all drivers, and thus to be
excluded from the all-drivers build.
Fix by ensuring that the per-driver section of the Makefile is
generated even when there are no ROMs to be built.
Reported-by: Sven Dreyer <sven@dreyer-net.de>
Signed-off-by: Michael Brown <mcb30@ipxe.org>
WinPE has been observed to call PXENV_UNDI_SHUTDOWN but not
PXENV_STOP_UNDI. This means that Hermon hardware is left partially
active (firmware running and one event queue mapped) when WinPE starts
up, which can cause a Blue Screen of Death.
Fix by ensuring that the hardware is left quiescent (with the firmware
stopped) when no interfaces are open.
Reported-by: Itay Gazit <itayg@mellanox.co.il>
Signed-off-by: Michael Brown <mcb30@ipxe.org>
Avoid spurious matches for peer key 0 against empty peer cache
entries, and set the LL_MULTICAST flag in addition to LL_BROADCAST.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
The ChipCmd register is only an 8-bit register. The 16-bit access
used by iPXE was causing an issue when used with qemu emulated rtl8139
device which was improperly aligning IOs.
Signed-off-by: Julian Pidancet <julian.pidancet@gmail.com>
Signed-off-by: Michael Brown <mcb30@ipxe.org>
Allow an initrd (such as an embedded script) to be passed to iPXE when
loaded as a .lkrn (or .iso) image. This allows an embedded script to
be varied without recompiling iPXE.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
Specify a driver name of "undionly" and a device name based on the
UNDI-reported underlying hardware device. For example:
net0: 52:54:00:12:34:56 using undionly on UNDI-PCI00:03.0 (open)
Signed-off-by: Michael Brown <mcb30@ipxe.org>
Drivers are currently expected to initialise only the hardware
address, with the link-layer protocol code taking care of converting
this into a valid link-layer address. Some drivers (e.g. undinet) can
legitimately determine both the hardware and link-layer addresses,
which may differ.
Allow for this situation by checking to see if the link-layer address
is empty before initialising it from the hardware address.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
Some BIOSes are reported to corrupt %ebx when using INT 15,2401 (see
http://opensolaris.org/jive/thread.jspa?messageID=377026). Guard
against this by preserving all (non-segment) registers.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
The symbol_text16 is defined globally by the linker. Use rm_text16
instead of _text16 for the local variable within librm.S to avoid
confusion when reading linker maps.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
All users of imgdownload() require registration of the image, so make
registration an integral part of imgdownload() itself and simplify the
"action" parameter to be one of image_select(), image_exec() et al.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
The "sleep" command is generally useful to have. For example:
:dhcp_retry
dhcp && goto dhcp_done
sleep 5
goto dhcp_retry
:dhcp_done
Make the "sleep" command available by default, leaving TIME_CMD
controlling only the (fairly specialist) "time" command.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
Arbel seems to crash the system as soon as the first send WQE
completes on an RC queue pair. (NOPs complete successfully, so this
is a problem specific to the work queue rather than the completion
queue.) The cause of this problem has remained unknown for over a
year.
Check in the non-functioning code to avoid bit-rot, and in the hope
that someone will find the fix.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
This self-test mechanism is inspired by Perl's Test::Simple and
similar modules. The aim is to encourage the use of self-tests by
making it as easy as possible to create self-test code
Signed-off-by: Michael Brown <mcb30@ipxe.org>
iPXE currently uses the last four bytes of the MAC address as the DHCP
transaction identifier. Reduce the probability of collisions by
generating a random transaction identifier.
Originally-implemented-by: Amos Kong <akong@redhat.com>
Signed-off-by: Michael Brown <mcb30@ipxe.org>
Provide a utility to quickly determine the ROM size and .mrom format
support for attached PCI devices. For example:
01:00.0 (1186:4300) supports a 128kB .rom or .mrom
Inspired-by: Wes Frazier <wes.frazier@members.fsf.org>
Signed-off-by: Michael Brown <mcb30@ipxe.org>
TCP currently neglects to allow sufficient space for its own headers
when allocating I/O buffers. This problem is masked by the fact that
the maximum link-layer header size (802.11) is substantially larger
than the common Ethernet link-layer header.
Fix by allowing sufficient space for any TCP headers, as well as the
network-layer and link-layer headers.
Reported-by: Scott K Logan <logans@cottsay.net>
Debugged-by: Scott K Logan <logans@cottsay.net>
Tested-by: Scott K Logan <logans@cottsay.net>
Signed-off-by: Michael Brown <mcb30@ipxe.org>
The version field of an X.509 certificate appears to be optional.
Reported-by: Sebastiano Manusia <Sebastiano.Manusia@chuv.ch>
Signed-off-by: Michael Brown <mcb30@ipxe.org>
CRLF line terminators are allowed in scripts; the carriage return is
simply interpreted as trailing whitespace and so is ignored. This
fails on lines containing script labels, since the label-finding code
checks for a line containing only the ":" marker and the label itself
(without any trailing whitespace).
Fix by allowing a label to be terminated by either a NUL or a
whitespace character.
Reported-by: Bovey Christian <Christian.Bovey@chuv.ch>
Signed-off-by: Michael Brown <mcb30@ipxe.org>
iPXE specifies a value of 0 for cmdline_size, causing GRUB to not pass
in a command line. Fix by setting cmdline_size to the maximum value
of 2047.
Signed-off-by: Valentine Barshak <gvaxon@gmail.com>
Signed-off-by: Michael Brown <mcb30@ipxe.org>
timer->refcnt is allowed to be NULL, in which case the timer's
expired() method may end up freeing the timer object.
Discovered using valgrind.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
When transmitting, use the broadcast link-layer address for any
broadcast address (e.g. 192.168.0.255), not just INADDR_BROADCAST
(255.255.255.255).
Signed-off-by: Michael Brown <mcb30@ipxe.org>
Explicitly discard any unicast packets for addresses that we do not
control, to avoid unexpected behaviour when operating in promiscuous
mode (which is now the default, thanks to FCoE).
Signed-off-by: Michael Brown <mcb30@ipxe.org>
Allow the link layer to directly report whether or not a packet is
multicast or broadcast at the time of calling pull(), rather than
relying on heuristics to determine this at a later stage.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
According to section 14.23 of RFC2616, an HTTP Host header without
port implies the default port is used. Thus, when fetching from
anywhere but port 80 for HTTP or 443 for HTTPS, the port ought to be
explicitly given in that header. Otherwise, some servers might fail
to associate the request with the correct virtual host or generate
incorrect self-referencing URLs.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
Reported-by: Stefan Hajnoczi <stefanha@gmail.com>
Signed-off-by: Thomas Miletich <thomas.miletich@gmail.com>
Signed-off-by: Michael Brown <mcb30@ipxe.org>
The iSCSI TX process can now be woken up by the TCP socket via
xfer_window_changed(), so it is no longer valid to assume that
iscsi_tx_step() can be called in state ISCSI_TX_IDLE only immediately
after completing a transmission.
Fix by calling iscsi_tx_done() only upon a transition into state
ISCSI_TX_IDLE.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
Some older versions of gcc issue a warning if -ffunction-sections is
used in combination with -g (gcc bug #18553). Inhibit
-ffunction-sections when building with such a version of gcc.
Reported-by: zhengwei <zw111_2001@126.com>
Signed-off-by: Michael Brown <mcb30@ipxe.org>
Provide support for HTTP range requests, and expose this functionality
via the iPXE block device API. This allows SAN booting from a root
path such as:
sanboot http://boot.ipxe.org/freedos/fdfullcd.iso
Signed-off-by: Michael Brown <mcb30@ipxe.org>
Allow objects to support both streaming and block device protocols, by
starting streaming data only when the data transfer window opens.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
Polling for the data-transfer window to become open is wasteful. We
can eliminate the polling loop by using hw_step() as the handler for
an xfer_window_changed() event.
If the window is already open at the time of instantiation, then
xfer_window_changed() may never be called. We can cover this case by
using hw_step() as the step() method of a one-shot process. Since the
signature for an xfer_window_changed() method is identical to the
signature for a process step() method, the same function can be used
for both.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
Some processes execute only once, and exist solely in order to defer
execution until after the relevant instantiator method has returned.
Such processes do not need to be automatically rescheduled when
executing.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
Give the step() method a pointer to the containing object, rather than
a pointer to the process. This is consistent with the operation of
interface methods, and allows a single function to serve as both an
interface method and a process step() method.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
Modify the default action for xfer_vredirect() to automatically send
xfer_window_changed() messages to both the new child and the parent
interfaces. This will allow the elimination of processes that simply
poll on xfer_window() to determine when a redirection has completed
successfully.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
ftp_data_deliver() does nothing except pass through the received data
to the xfer interface, and so can be eliminated by using a
pass-through interface.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
Some bootloaders seem to add "BOOT_IMAGE=..." at the end of the
command line; some at the start. Cope with either variation.
Reported-by: Dave Hansen <dave@sr71.net>
Signed-off-by: Michael Brown <mcb30@ipxe.org>
At the time of attempting ARP resolution, we already know the
transmitting network device. We can therefore record ARP errors using
netdev_tx_err() so that they show up in the output of "ifstat".
Inspired-by: Dominik Russenberger <dominik.russenberger@terreactive.ch>
Signed-off-by: Michael Brown <mcb30@ipxe.org>
Allow TX errors to be recorded against a network device even when the
packet didn't make it as far as netdev_tx().
Inspired-by: Dominik Russenberger <dominik.russenberger@terreactive.ch>
Signed-off-by: Michael Brown <mcb30@ipxe.org>
IBM BIOSes ignore the PnP header offset stored at address 0x1a and
instead scan for the $PnP signature on a 16-byte boundary. (This
alignment is not mandated by the PnP specification.)
Force PnP header to a 16-byte boundary to work around these BIOSes.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
Several BIOSes (including most IBM BIOSes and many virtual machine
BIOSes) do not provide detectable PnP support, but will use the BEV
entry point for a PnP option ROM. On these semi-PnP BIOSes, iPXE will
respond to the absence of detectable PnP support by hooking INT19,
which disrupts the boot order.
BIOSes that genuinely require hooking INT19 seem to be very rare
nowadays. It may therefore be preferable to assume that the absence
of detectable PnP support indicates a semi-PnP BIOS rather than a
non-PnP BIOS.
Change the default behaviour so that INT19 will never be hooked unless
the compile-time option NONPNP_HOOK_INT19 is enabled. Leave the
redundant PnP detection routine in-place to allow for debugging via
the ROM banner line.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
