[lkrnprefix] Copy command line before installing iPXE
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>
[pxe] Provide PXENV_FILE_EXIT_HOOK only for ipxelinux.0 builds
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>
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>
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>
[romprefix] Force PnP header to a 16-byte boundary for IBM BIOSes
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>
[romprefix] Do not fall back to hooking INT19 by default
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>
[romprefix] Remove special treatment for IBM BIOSes
Revert commit 38cd351 ("[romprefix] Attempt to gracefully handle
semi-PnP IBM BIOSes"), since the test for the "IBM " signature in %edi
is not sufficient to identify an IBM BIOS.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
[romprefix] Attempt to gracefully handle semi-PnP IBM BIOSes
Some IBM BIOSes provide partial support for PnP: they will use the BEV
entry point but will not advertise PnP support. This causes iPXE to
hook INT 19, which disrupts the boot process.
Attempt to improve this situation by detecting an IBM BIOS and
treating it as a PnP BIOS despite the absence of a PnP signature.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
An iPXE .exe image can be loaded from DOS. Tested using bin/ipxe.exe
to load a Linux kernel and simple initramfs from within MS-DOS 6.22.
(EDD must be disabled using the "edd=off" kernel parameter, since the
loaded kernel image has already overwritten parts of DOS' INT 13
wrapper.)
Signed-off-by: Michael Brown <mcb30@ipxe.org>
[prefix] Avoid using base memory for temporary decompression area
In the unlikely (but observable) event that INT 15,88 returns less
memory above 1MB than is required for the temporary decompression
area, ignore it and use the 1MB point anyway.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
[romprefix] Use correct size for PMM allocation of image source block
iPXE allocates its first PMM block using the image source length,
which is rounded up to the nearest 16-byte paragraph. It then copies
in data of a length calculated from the ROM size, which is
theoretically less than or equal to the image source length, but is
rounded up to the nearest 512-byte sector. This can result in copying
beyond the end of the allocated PMM block, which can corrupt the PMM
data structures (and other essentially arbitrary areas of memory).
Fix by rounding up the image source length to the nearest 512-byte
sector before using it as the PMM allocation length.
Reported-by: Alex Williamson <alex.williamson@redhat.com>
Reported-by: Jarrod Johnson <jarrod.b.johnson@gmail.com>
Reported-by: Itay Gazit <itayg@mellanox.co.il>
Signed-off-by: Michael Brown <mcb30@ipxe.org>
[prefix] Allow iPXE's own command line to be executed as a script
Some prefixes (e.g. .lkrn) allow a command line to be passed in to
iPXE. At present, this command line is ignored.
If a command line is provided, treat it as an embedded script (without
an explicit "#!ipxe" magic marker). This allows for patterns of
invocation such as
title iPXE
kernel /boot/ipxe.lkrn dhcp && \
sanboot iscsi:10.0.4.1::::iqn.2010-04.org.ipxe.dolphin:storage
Here GRUB is instructed to load ipxe.lkrn with an embedded script
equivalent to
#!ipxe
dhcp
sanboot iscsi:10.0.4.1::::iqn.2010-04.org.ipxe.dolphin:storage
This can be used to effectively vary the embedded script without
having to rebuild ipxe.lkrn.
Originally-implemented-by: Dave Hansen <dave@sr71.net>
Signed-off-by: Michael Brown <mcb30@ipxe.org>
[prefix] Set the "size" bit in the GDT entry for the flat data segment
The "size" bit (aka the D/B) bit should (as far as I can tell) be
irrelevant for accesses to a non-code, non-stack, expand-upwards
segment. However, VirtualBox fails on some accesses via this segment
if this bit is not set.
This change allows iPXE to boot under VirtualBox without having to
disable VT-x/AMD-V support.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
Some binutils versions will drag in an object to satisfy the entry
symbol; some won't. Try to cope with this exciting variety of
behaviour by ensuring that all entry symbols are unique.
Remove the explicit inclusion of the prefix object on the linker
command line, since the entry symbol now provides all the information
needed to identify the prefix.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
[build] Ensure an entry point symbol exists in all builds
Commit 623469d ("[build] Eliminate unused sections at link-time")
introduced a regression in several build formats, in which the prefix
would end up being garbage-collected out of existence. Fix by
ensuring that an entry symbol exists in each possible prefix, and is
required by the linker script.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
Flat real mode will have been set up as a side-effect of the
protected-mode call invoked during install_block() for .text16.early;
there is no need to do so explicitly.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
[prefix] Use 16-bit protected mode for access to high memory
Flat real mode works perfectly on real hardware, but seems to cause
problems for some hypervisors. Revert to using 16-bit protected mode
(and returning to real mode with 4GB limits, so as not to break PMM
BIOSes).
Allow the code specific to the .mrom format to continue to assume that
flat real mode works, since this format is specific to real hardware.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
Support qemu-like arguments for network setup:
--net driver_name[,setting=value]*
and global settings:
--settings setting=value[,setting=value]*
Signed-off-by: Piotr Jaroszyński <p.jaroszynski@gmail.com>
Signed-off-by: Michael Brown <mcb30@ipxe.org>
The existence and usage of the BEV entry point is covered by the PnP
spec, not the BBS spec; the BBS spec merely describes a policy for
selecting the boot device order. iPXE should therefore check only for
a PnP BIOS in order to decide whether or not to hook INT19.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
[romprefix] Add .mrom format, allowing loading of large ROMs
Add an infrastructure allowing the prefix to provide an open_payload()
method for obtaining out-of-band access to the whole iPXE image. Add
a mechanism within this infrastructure that allows raw access to the
expansion ROM BAR by temporarily borrowing an address from a suitable
memory BAR on the same PCI card.
For cards that have a memory BAR that is at least as large as their
expansion ROM BAR, this allows large iPXE ROMs to be supported even on
systems where PMM fails, or where option ROM space pressure makes it
impossible to use PMM shrinking. The BIOS sees only a stub ROM of
approximately 3kB in size; the remainder (which can be well over 64kB)
is loaded only at the time iPXE is invoked.
As a nice side-effect, an iPXE .mrom image will continue to work even
if its PMM-allocated areas are overwritten between initialisation and
invocation.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
[romprefix] Inhibit the use of relocation during POST
It is common for system memory maps to be grotesquely unreliable
during POST. Many sanity checks have been added to the memory map
reading code, but these do not catch all problems.
Skip relocation entirely if called during POST. This should avoid the
problems typically encountered, at the cost of slightly disrupting the
memory map of an operating system booted via iPXE when iPXE was
entered during POST. Since this is a very rare special case (used,
for example, when reflashing an experimental ROM that would otherwise
prevent the system from completing POST), this is an acceptable cost.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
[romprefix] Split PMM allocations for image source and decompression area
Some BIOSes (at least some AMI BIOSes) tend to refuse to allocate a
single area large enough to hold both the iPXE image source and the
temporary decompression area, despite promising a largest available
PMM memory block of several megabytes. This causes ROM image
shrinking to fail on these BIOSes, with undesirable consequences:
other option ROMs may be disabled due to shortage of option ROM space,
and the iPXE ROM may itself be corrupted by a further BIOS bug (again,
observed on an AMI BIOS) which causes large ROMs to end up overlapping
reserved areas of memory. This can potentially render a system
unbootable via any means.
Increase the chances of a successful PMM allocation by dropping the
alignment requirement (which is redundant now that we can enable A20
from within the prefix); this allows us to reduce the allocation size
from 2MB down to only the required size.
Increase the chances still further by using two separate allocations:
one to hold the image source (i.e. the copy of the ROM before being
shrunk) and the other to act as the decompression area. This allows
ROM image shrinking to take place even on systems that fail to
allocate enough memory for the temporary decompression area.
Improve the behaviour of iPXE in systems with multiple iPXE ROMs by
sharing PMM allocations where possible. Image source areas can be
shared with any iPXE ROMs with a matching build identifier, and the
temporary decompression area can be shared with any iPXE ROMs with the
same uncompressed size (rounded up to the nearest 128kB).
Signed-off-by: Michael Brown <mcb30@ipxe.org>
[prefix] Use area at top of INT 15,88 memory map for temporary decompression
Use INT 15,88 to find a suitable temporary decompression area, rather
than a fixed address. This hopefully gives us a better chance of not
treading on any PMM-allocated areas, in BIOSes where PMM support
exists but tends not to give us the large blocks that we ask for.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
Randomly generate a 32-bit build identifier that can be used to
identify identical iPXE ROMs when multiple such ROMs are present in a
system (e.g. when a multi-function NIC exposes the same iPXE ROM image
via each function's expansion ROM BAR).
Signed-off-by: Michael Brown <mcb30@ipxe.org>
[romprefix] Provide indication of successful call to install_prealloc
The existing "iPXE starting execution" message indicates that the BEV
(or INT19) was invoked, but gives no indication on whether or not the
iPXE source was successfully retrieved (e.g. from PMM). Split the
"starting execution message" into "starting execution...ok"; the "ok"
indicates that the main iPXE body was successfully decompressed and
relocated.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
[prefix] Default to 1MB mark as fallback high memory load point
Now that we can use odd megabytes, there is no particular need to use
an even megabyte as the fallback temporary load point.
Note that the old warnings about avoiding 2MB pre-date our ability to
cooperate with other PXE ROMs by using PMM.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
iPXE currently insists on residing in an even megabyte. This imposes
undesirably severe constraints upon our PMM allocation strategy, and
limits our options for mechanisms to access ROMs greater than 64kB in
size.
Add A20 handling code to libflat so that prefixes are able to access
memory even in odd megabytes.
The algorithms and tuning parameters in the new A20 handling code are
based upon a mixture of the existing iPXE A20 code and the A20 code
from the 2.6.32 Linux kernel.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
The flatten_real_mode routine is not needed until after decompressing
.text16.early, and currently performs various contortions to
compensate for the fact that .prefix may not be writable. Move
flatten_real_mode to .text16.early to save on (compressed) binary size
and simplify the code.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
Add a section .text16.early which is always kept inline with the
prefix. This will allow for some code sharing between the .prefix and
.text16 sections.
Note that the simple solution of just prepending the .prefix section
to the .text16 section will not work, because a bug in Wyse Streaming
Manager server (WLDRM13.BIN) requires us to place a dummy PXENV+ entry
point at the start of .text16.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
[prefix] Use flat real mode for access to high memory
Use flat real mode rather than 16-bit protected mode for access to
high memory during installation. This simplifies the code by reducing
the number of CPU modes we need to think about, and also increases the
amount of code in common between the normal and (somewhat
hypothetical) KEEP_IT_REAL methods of operation.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
When returning to real mode, set 4GB segment limits instead of 64kB
limits. This change improves our chances of successfully returning to
a PMM-capable BIOS aftering entering iPXE during POST; the BIOS will
have set up flat real mode before calling our initialisation point,
and may be disconcerted if we then return in genuine real mode.
This change is unlikely to break anything, since any code that might
potentially access beyond 64kB must use addr32 prefixes to do so; if
this is the case then it is almost certainly code written to expect
flat real mode anyway.
Note that it is not possible to restore the real-mode segment limits
to their original values, since it is not possible to know which
protected-mode segment descriptor was originally used to initialise
the limit portion of the segment register.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
The .hrom prefix provides an experimental mechanism for reducing
option ROM space usage on systems where PMM allocation fails, by
pretending that PMM allocation succeeded and gave us an address fixed
at compilation time. This is unreliable, and potentially dangerous.
In particular, when multiple gPXE ROMs are present in a system, each
gPXE ROM will assume ownership of the same fixed address, resulting in
undefined behaviour.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
The .xrom prefix provides an experimental mechanism for loading ROM
images greater than 64kB in size by mapping the expansion ROM BAR in
at a hopefully-unused address. This is unreliable, and potentially
dangerous. In particular, there is no guarantee that any PCI bridges
between the CPU and the device will respond to accesses for the
"unused" memory region that is chosen, and it is possible that the
process of scanning for the "unused" memory region may end up issuing
reads to other PCI devices. If this ends up trampling on a register
with read side-effects belonging to an unrelated PCI device, this may
cause undefined behaviour.
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>
The .elf, .elfd, .lmelf, and .lmelfd prefices were brought over from
legacy Etherboot and they do not build in gPXE. This patch removes the
ELF prefices.
Signed-off-by: Stefan Hajnoczi <stefanha@gmail.com>
Signed-off-by: Marty Connor <mdc@etherboot.org>
The unfinished .exe prefix was brought over from legacy Etherboot.
There has been no demand for .exe images so this patch removes the
prefix.
Signed-off-by: Stefan Hajnoczi <stefanha@gmail.com>
Signed-off-by: Marty Connor <mdc@etherboot.org>
The DOS .com prefix was brought over from legacy Etherboot but does not
build. There has been no demand for .com images so this patch removes
the prefix.
Signed-off-by: Stefan Hajnoczi <stefanha@gmail.com>
Signed-off-by: Marty Connor <mdc@etherboot.org>
The .lkrn prefix allows gPXE to be loaded as a Linux bzImage. The
bImage prefix was carried over from legacy Etherboot and does not build.
This patch removes the .bImage prefix, use .lkrn instead.
Signed-off-by: Stefan Hajnoczi <stefanha@gmail.com>
Signed-off-by: Marty Connor <mdc@etherboot.org>
Till Straumann