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>

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>

Requested-by: Savitha Hiriyannaia <Savitha.Hiriyannaiah@emulex.com>
Signed-off-by: Michael Brown <mcb30@ipxe.org>

Some PXE stacks (notably old Etherboot/gPXE stacks) will claim to use
the timer interrupt, rather than reporting that interrupts are not
supported.  Since using the timer interrupt is equivalent to polling
anyway, we may as well genuinely poll these stacks.

Signed-off-by: Michael Brown <mcb30@ipxe.org>

Some PXE stacks advertise that interrupts are not supported, despite
requiring the use of interrupts.  Attempt to cope with such cards
without breaking others by always hooking the interrupt, and using the
"interrupts supported" flag only to decide whether or not to wait for
an interrupt before calling PXENV_UNDI_ISR_IN_PROCESS.

The possible combinations are therefore:

1. Card generates interrupts and claims to support interrupts

   iPXE will call PXENV_UNDI_ISR_IN_PROCESS only after an interrupt
   has been observed.  (This is required to avoid lockups in some PXE
   stacks, which spuriously sulk if called before an interrupt has
   been generated.)

   Such a card should work correctly.

2. Card does not generate interrupts and does not claim to support
   interrupts

   iPXE will call PXENV_UNDI_ISR_IN_PROCESS indiscriminately, matching
   the observed behaviour of at least one other PXE NBP (winBoot/i).

   Such a card should work correctly.

3. Card generates interrupts but claims not to support interrupts

   iPXE will call PXENV_UNDI_ISR_IN_PROCESS indiscriminately.  An
   interrupt will still result in a call to PXENV_UNDI_ISR_IN_START.

   Such a card may work correctly.

4. Card does not generate interrupts but claims to support interrupts

   Such a card will not work at all.

Reported-by: Jerry Cheng <jaspers.cheng@msa.hinet.net>
Tested-by: Jerry Cheng <jaspers.cheng@msa.hinet.net>
Reported-by: Mauricio Silveira <mauricio@livreti.com.br>
Tested-by: Mauricio Silveira <mauricio@livreti.com.br>
Signed-off-by: Michael Brown <mcb30@ipxe.org>

Some network cards do not generate interrupts when operated via the
UNDI API.  Allow for this by waiting for the ISR to be triggered only
if the PXE stack advertises that it supports interrupts.  When the PXE
stack does not advertise interrupt support, we skip the call to
PXENV_UNDI_ISR_IN_START and just poll the device using
PXENV_UNDI_ISR_IN_PROCESS.  This matches the observed behaviour of at
least one other PXE NBP (emBoot's winBoot/i), so there is a reasonable
chance of this working.

Originally-implemented-by: Muralidhar Appalla <Muralidhar.Appalla@emulex.com>
Signed-off-by: Michael Brown <mcb30@ipxe.org>

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>

Calling the parent PXE stack (the stack that loaded us, for
undionly.kkpxe) can be useful for more than UNDI calls; for instance,
it lets us get cached DHCP packets to avoid re-DHCP when working with
embedded images.

Signed-off-by: Marty Connor <mdc@etherboot.org>

The hardware address is an intrinsic property of the hardware, while
the link-layer address can be changed at runtime.  This separation is
exposed via APIs such as PXE and EFI, but is currently elided by gPXE.

Expose the hardware and link-layer addresses as separate properties
within a net device.  Drivers should now fill in hw_addr, which will
be used to initialise ll_addr at the time of calling
register_netdev().

Add FILE_LICENCE declarations to almost all files that make up the
various standard builds of gPXE.

Certain combinations of PXE stack and BIOS result in a broken INT 18
call, which will leave the system displaying a "PRESS ANY KEY TO
REBOOT" message instead of proceeding to the next boot device.  On
these systems, returning via the PXE stack is the only way to continue
to the next boot device.  Returning via the PXE stack works only if we
haven't already blown away the PXE base code in pxeprefix.S.

In most circumstances, we do want to blow away the PXE base code.
Base memory is a limited resource, and it is desirable to reclaim as
much as possible.  When we perform an iSCSI boot, we need to place the
iBFT above the 512kB mark, because otherwise it may not be detected by
the loaded OS; this may not be possible if the PXE base code is still
occupying that memory.

Introduce a new prefix type .kkpxe which will preserve both the PXE
base code and the UNDI driver (as compared to .kpxe, which preserves
the UNDI driver but uninstalls the PXE base code).  This prefix type
can be used on systems that are known to experience the specific
problem of INT 18 being broken, or in builds (such as gpxelinux.0) for
which it is particularly important to know that returning to the BIOS
will work.

Written by H. Peter Anvin <hpa@zytor.com> and Stefan Hajnoczi
<stefanha@gmail.com>, minor structural alterations by Michael Brown
<mcb30@etherboot.org>.

There are many functions that take ownership of the I/O buffer they
are passed as a parameter.  The caller should not retain a pointer to
the I/O buffer.  Use iob_disown() to automatically nullify the
caller's pointer, e.g.:

    xfer_deliver_iob ( xfer, iob_disown ( iobuf ) );

This will ensure that iobuf is set to NULL for any code after the call
to xfer_deliver_iob().

iob_disown() is currently used only in places where it simplifies the
code, by avoiding an extra line explicitly setting the I/O buffer
pointer to NULL.  It should ideally be used with each call to any
function that takes ownership of an I/O buffer.  (The SSA
optimisations will ensure that use of iob_disown() gets optimised away
in cases where the caller makes no further use of the I/O buffer
pointer anyway.)

If gcc ever introduces an __attribute__((free)), indicating that use
of a function argument after a function call should generate a
warning, then we should use this to identify all applicable function
call sites, and add iob_disown() as necessary.

This brings us in to line with Linux definitions, and also simplifies
adding x86_64 support since both platforms have 2-byte shorts, 4-byte
ints and 8-byte long longs.

The userptr_t is now the fundamental type that gets used for conversions.
For example, virt_to_phys() is implemented in terms of virt_to_user() and
user_to_phys().

__from_data16 and __from_text16 now take a pointer to a
.data16/.text16 variable, and return the real-mode offset within the
appropriate segment.  This matches the use case for every occurrence
of these macros, and prevents potential future bugs such as that fixed
in commit d51d80f.  (The bug arose essentially because "&pointer" is
still syntactically valid.)

We never set up specific multicast filters; native drivers will ask
the card to receive all multicast packets.  The only way to achieve
this via the UNDI API is to enable promiscuous mode.

Add ability for network devices to flag link up/down state to the
networking core.

Autobooting code will now wait for link-up before attempting DHCP.

IPoIB reflects the Infiniband link state as the network device link state
(which is not strictly correct; we also need a succesful IPoIB IPv4
broadcast group join), but is probably more informative.

allow the UNDI NIC interrupt to happen.

bytes of useless zeroes in the final image.

the UNDI stack.

Ignore obviously invalid length combinations (as returned by
e.g. VMWare's PXE stack).

Limit to one packet per poll to avoid memory exhaustion.

safe dropping of the netdev ref by the driver while other refs still
exist.

Add netdev_irq() method.  Net device open()/close() methods should no
longer enable or disable IRQs.

Remove rx_quota; it wasn't used anywhere and added too much complexity
to implementing correct interrupt-masking behaviour in pxe_undi.c.

by PXE and NBI) and UNDI packets (as used by undinet and UNDI).

structures.

DHCP still broken and #if 0'd out.

Achieved via Perl using:

perl -pi -e 's/pk_buff/io_buffer/g; s/Packet buffer/I\/O buffer/ig; ' \
	-e 's/pkbuff\.h/iobuf.h/g; s/pkb_/iob_/g; s/_pkb/_iob/g; ' \
	-e 's/pkb/iobuf/g; s/PKB/IOB/g;'

clean separation between loading and starting, but does mean that more
PXE stacks survive the process.

don't overwrite the parameter block until *after* the debug code.

clue what the "previous" interrupt handler will do, which could range
from "just an iret" to "disable the interrupt"), and that means that
we have to take responsibility for ACKing all interrupts.  Joy.

names.

Add "dev" pointer in struct net_device to tie network interfaces back to a
hardware device.

Force natural alignment of data types in __table() macros.  This seems to
prevent gcc from taking the unilateral decision to occasionally increase
their alignment (which screws up the table packing).

of alloc_pkb() exhaustion when e.g. an iSCSI-booted DOS session is left
idle for a long time at the C:\ prompt and builds up a huge packet
backlog.

skb_tailroom().  Add pkb_headroom().

(which will need us to wait for TX completions).

Added debug autocolourisation to netdevice.c

This will allow us to implement RX quotas.

to the PIC while it was disabled.

function prefix "undinet_" and the variable name "undinic" in undinet.c,
so that we can reserve the variable name "undi" for a struct undi_device.

The idea is that we preserve the Etherboot 5.4 convention that the "UNDI"
code refers to our using an underlying UNDI stack, while the "PXE" code
refers to our providing a PXE API.