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Signed-off-by: Michael Brown <mcb30@ipxe.org>
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The "shim" command will skip downloading the shim binary (and is
therefore a conditional no-op) if there is already a selected EFI
image that can be executed directly via LoadImage()/StartImage().
This allows the same iPXE script to be used with Secure Boot either
enabled or disabled.
Generalise this further to provide a dummy "shim" command that is an
unconditional no-op on non-EFI platforms. This then allows the same
iPXE script to be used for BIOS, EFI with Secure Boot disabled, or EFI
with Secure Boot enabled.
The same effect could be achieved by using "iseq ${platform} efi"
within the script, but this would complicate end-user documentation.
To minimise the code size impact, the dummy "shim" command is a pure
no-op that does not call parse_options() and so will ignore even
standardised arguments such as "--help".
Signed-off-by: Michael Brown <mcb30@ipxe.org>
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The UEFI shim implements a fairly nicely designed revocation mechanism
designed around the concept of security generations. Unfortunately
nobody in the shim community has thus far added the relevant metadata
to the Linux kernel, with the result that current versions of shim are
incapable of booting current versions of the Linux kernel.
Experience shows that there is unfortunately no point in trying to get
a fix for this upstreamed into shim. We therefore default to working
around this undesirable behaviour by patching data read from the
"SbatLevel" variable used to hold SBAT configuration.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
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Signed-off-by: Michael Brown <mcb30@ipxe.org>
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Allow a shim to be used to facilitate booting a kernel using a script
such as:
kernel /images/vmlinuz console=ttyS0,115200n8
initrd /images/initrd.img
shim /images/shimx64.efi
boot
Signed-off-by: Michael Brown <mcb30@ipxe.org>
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Add support for using a shim as a helper to execute an EFI image.
When a shim has been specified via shim(), the shim image will be
passed to LoadImage() instead of the selected EFI image and the
command line will be prepended with the name of the selected EFI
image. The selected EFI image will be accessible to the shim via the
virtual filesystem as a hidden file.
Reduce the Secure Boot attack surface by removing, where possible, the
spurious requirement for a third party second stage loader binary such
as GRUB to be used solely in order to call the "shim lock protocol"
entry point.
Do not install the EFI PXE APIs when using a shim, since if shim finds
EFI_PXE_BASE_CODE_PROTOCOL on the loaded image's device handle then it
will attempt to download files afresh instead of using the files
already downloaded by iPXE and exposed via the EFI_SIMPLE_FILE_SYSTEM
protocol. (Experience shows that there is no point in trying to get a
fix for this upstreamed into shim.)
Signed-off-by: Michael Brown <mcb30@ipxe.org>
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The UEFI shim includes a "shim lock protocol" that can be used by a
third party second stage loader such as GRUB to verify a kernel image.
Add definitions for the relevant portions of this protocol interface.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
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Signed-off-by: Michael Brown <mcb30@ipxe.org>
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Most image flags are independent values: any combination of flags may
be set for any image, and the flags for one image are independent of
the flags for any other image. The "selected" flag does not follow
this pattern: at most one image may be marked as selected at any time.
When invoking a kernel via the UEFI shim, there will be multiple
"special" images: the selected kernel itself, the shim image, and
potentially a shim-signed GRUB binary to be used as a crutch to assist
shim in loading the kernel (since current versions of the UEFI shim
are not capable of directly loading a Linux kernel).
Remove the "selected" image flag and replace it with a general concept
of an image tag with the same semantics: a given tag may be assigned
to at most one image, an image may be found by its tag only while the
image is currently registered, and a tag will survive unregistration
and reregistration of an image (if it has not already been assigned to
a new image). For visual consistency, also replace the current image
pointer with a current image tag.
The image pointer stored within the image tag holds only a weak
reference to the image, since the selection of an image should not
prevent that image from being freed. (The strong reference to the
currently executing image is held locally within the execution scope
of image_exec(), and is logically separate from the current image
pointer.)
Signed-off-by: Michael Brown <mcb30@ipxe.org>
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An EFI image that is rejected by LoadImage() due to failing Secure
Boot verification is still an EFI image. Unfortunately, the extremely
broken UEFI Secure Boot model provides no way for us to unambiguously
determine that a valid EFI executable image was rejected only because
it failed signature verification. We must therefore use heuristics to
guess whether not an image that was rejected by LoadImage() could
still be loaded via a separate PE loader such as the UEFI shim.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
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The libc6-dbg:i386 package has spontaneously started failing to
install from the Azure package repositories used by the GitHub Actions
runners, with the somewhat recalcitrant error message:
libc6:i386: Depends: libgcc-s1:i386 but it is not going to be installed
Work around this unexplained issue by explicitly requesting
installation of the libgcc-s1:i386 package.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
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Versions 15.4 and earlier of the UEFI shim are incapable of correctly
parsing the command line in order to extract the second stage loader
filename, and will always attempt to load "grubx64.efi" or equivalent.
Versions 15.3 and later of the UEFI shim are currently incapable of
loading a Linux kernel directly anyway, since the kernel does not
include SBAT metadata. These versions will require a genuine
shim-signed GRUB binary to be used as a crutch to assist shim in
loading a Linux kernel.
This leaves versions 15.2 and earlier of the UEFI shim (as currently
used in e.g. RHEL7) as being capable of directly loading a Linux
kernel, but incorrectly attempting to load it using the filename
"grubx64.efi" or equivalent. To support the bugs in these older
versions of the UEFI shim, allow the currently selected image to be
opened via any filename of the form "grub*.efi".
Signed-off-by: Michael Brown <mcb30@ipxe.org>
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When invoking a kernel via the UEFI shim, the kernel image must be
accessible via EFI_SIMPLE_FILE_SYSTEM_PROTOCOL but must not be present
in the magic initrd constructed from all registered images.
Re-register a currently executing EFI image and mark it as hidden,
thereby allowing it to be accessed via the virtual filesystem exposed
via EFI_SIMPLE_FILE_SYSTEM_PROTOCOL without appearing in the magic
initrd contents.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
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When invoking a kernel via the UEFI shim, the kernel (and potentially
also a helper binary such as GRUB) must be accessible via the virtual
filesystem exposed via EFI_SIMPLE_FILE_SYSTEM_PROTOCOL but must not be
present in the magic initrd constructed from all registered images.
Allow for images to be flagged as hidden, which will cause them to be
excluded from API-level lists of all images such as the virtual
filesystem directory contents, the magic initrd, or the Multiboot
module list. Hidden images remain visible to iPXE commands including
"imgstat", which will show a "[HIDDEN]" flag for such images.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
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Show the original filename as used by the consumer when calling our
EFI_SIMPLE_FILE_SYSTEM_PROTOCOL's Open() method.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
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Try searching for a matching registered image before checking for
fixed filenames (such as "initrd.magic" for the dynamically generated
magic initrd file). This minimises surprise by ensuring that an
explicitly downloaded image will always be used verbatim.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
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Hybrid bzImage and UEFI binaries (such as wimboot) include a bzImage
header within a section starting at offset zero, with the PE header
effectively occupying unused space within this section. This section
should not appear as a named section in the resulting PE file.
Allow for the existence of hidden sections that do not result in a
section header being written to the PE file.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
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Hybrid 32-bit BIOS and 64-bit UEFI binaries (such as wimboot) may
include R_X86_64_32 relocation records for the 32-bit BIOS portions.
These should be ignored when generating PE relocation records, since
they apply only to code that cannot be executed within the context of
the 64-bit UEFI binary, and creating a 4-byte relocation record is
invalid in a binary that may be relocated anywhere within the 64-bit
address space (see commit 907cffb "[efi] Disallow R_X86_64_32
relocations").
Add a "--hybrid" option to elf2efi, which will cause R_X86_64_32
relocation records to be silently discarded.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
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Hybrid bzImage and UEFI binaries (such as wimboot) require the PE
header to be kept as small as possible, since the bzImage header
starts at a fixed offset 0x1f1.
The EFI_IMAGE_OPTIONAL_HEADER structures in PeImage.h define an
optional header containing 16 data directory entries, of which the
last eight are unused in binaries that we create. Shrink the data
directory to contain only the first eight entries, to minimise the
overall size of the PE header.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
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Hybrid bzImage and UEFI binaries (such as wimboot) require the PE
header to be kept as small as possible, since the bzImage header
starts at a fixed offset 0x1f1.
The PE header currently includes 128 bytes of zero padding between the
DOS and NT header portions. This padding has been present since
commit 81d92c6 ("[efi] Add EFI image format and basic runtime
environment") first added support for EFI images in iPXE, and was
included on the basis of matching the observed behaviour of the
Microsoft toolchain. There appears to be no requirement for this
padding to exist: EDK2 binaries built with gcc include only 64 bytes
of zero padding, Linux kernel binaries include 66 bytes of non-zero
padding, and wimboot binaries include no padding at all.
Remove the unnecessary padding between the DOS and NT header portions
to minimise the overall size of the PE header.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
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Originally-implemented-by: Christopher Schenk <christopher@cschenk.net>
Signed-off-by: Michael Brown <mcb30@ipxe.org>
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Prepare for the possibility that a record handler may choose not to
consume the entire record by passing the I/O buffer and requiring the
handler to mark consumed data using iob_pull().
Signed-off-by: Michael Brown <mcb30@ipxe.org>
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Define and use data structures and constants for the (single-byte)
change cipher spec records.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
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As documented in commits 6a004be ("[efi] Support the initrd
autodetection mechanism in newer Linux kernels") and 04e60a2 ("[efi]
Omit EFI_LOAD_FILE2_PROTOCOL for a zero-length initrd"), the choice in
Linux of using a fixed device path requires bootloaders to allow for
the fact that a previous bootloader may have already installed a
handle with the fixed device path.
We currently deal with this situation by reusing the existing handle,
replacing the EFI_LOAD_FILE2_PROTOCOL instance with our own. Simplify
the code by instead uninstalling the EFI_DEVICE_PATH_PROTOCOL instance
from the existing handle (if present), thereby allowing the creation
of a new handle to succeed.
Create the new handle only if we have a non-empty initrd to provide.
This works around bugs in bootloaders such as the systemd EFI stub
that fail to allow for the existence of multiple-bootloader chains.
(The workaround is not comprehensive: if the user has downloaded other
images in iPXE before invoking the systemd Unified Kernel Image (UKI),
then the systemd EFI stub will still crash and burn since it fails to
allow for the fact that a previous bootloader has already installed a
handle with the fixed device path.)
Signed-off-by: Michael Brown <mcb30@ipxe.org>
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The Intel I210's packet buffer size registers reset only on power up,
not when a reset signal is asserted. This can lead to the inability
to pass traffic in the event that the DMA TX Maximum Packet Size
(which does reset to its default value on reset) is bigger than the TX
Packet Buffer Size.
For example, an operating system may be using the time sensitive
networking features of the I210 and the registers may be programmed
correctly, but then a reset signal is asserted and iPXE on the next
boot will be unable to use the I210.
Mimic what Linux does and forcibly set the registers to their default
values.
Signed-off-by: Matt Parrella <parrella.matthew@gmail.com>
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When a DHCP transaction does not result in the registration of a new
"proxydhcp" or "pxebs" settings block, any existing settings blocks
are currently left unaltered.
This can cause surprising behaviour. For example: when chainloading
iPXE, the "proxydhcp" and "pxebs" settings blocks may be prepopulated
using cached values from the previous PXE bootloader. If iPXE
performs a subsequent DHCP request, then the DHCP or ProxyDHCP servers
may choose to respond differently to iPXE. The response may choose to
omit the ProxyDHCP or PXEBS stages, in which case no new "proxydhcp"
or "pxebs" settings blocks may be registered. This will result in
iPXE using a combination of both old and new DHCP responses.
Fix by assuming that a successful DHCPACK effectively acquires
ownership of the "proxydhcp" and "pxebs" settings blocks, and that any
existing settings blocks should therefore be unregistered.
Reported-by: Henry Tung <htung@palantir.com>
Signed-off-by: Michael Brown <mcb30@ipxe.org>
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Signed-off-by: Michael Brown <mcb30@ipxe.org>
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We unregister script images during their execution, to prevent a
"boot" command from re-executing the containing script. This also has
the side effect of preventing executing scripts from showing up within
the Linux magic initrd image (or the Multiboot module list).
Additional logic in bzimage.c and efi_file.c prevents a currently
executing kernel from showing up within the magic initrd image.
Similar logic in multiboot.c prevents the Multiboot kernel from
showing up as a Multiboot module.
This still leaves some corner cases that are not covered correctly.
For example: when using a gzip-compressed kernel image, nothing will
currently hide the original compressed image from the magic initrd.
Fix by moving the logic that temporarily unregisters the current image
from script_exec() to image_exec(), so that it applies to all image
types, and simplify the magic initrd and Multiboot module list
construction logic on the basis that no further filtering of the
registered image list is necessary.
This change has the side effect of hiding currently executing EFI
images from the virtual filesystem exposed by iPXE. For example, when
using iPXE to boot wimboot, the wimboot binary itself will no longer
be visible within the virtual filesystem.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
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Signed-off-by: Michael Brown <mcb30@ipxe.org>
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Signed-off-by: Forest Crossman <cyrozap@gmail.com>
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Extend the request parameter mechanism to allow for arbitrary HTTP
headers to be specified via e.g.:
params
param --header Referer http://www.example.com
imgfetch http://192.168.0.1/script.ipxe##params
Signed-off-by: Michael Brown <mcb30@ipxe.org>
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Prepare for the parameter mechanism to be generalised to specifying
request parameters that are passed via mechanisms other than an
application/x-www-form-urlencoded form.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
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An attempt to use an existent but empty form parameter list will
currently result in an invalid POST request since the Content-Length
header will be missing.
Fix by using GET instead of POST if the form parameter list is empty.
This is a non-breaking change (since the current behaviour produces an
invalid request), and simplifies the imminent generalisation of the
parameter list concept to handle both header and form parameters.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
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When the Linux kernel is being used with no initrd, iPXE will still
provide a zero-length initrd.magic file within the virtual filesystem.
As of commit 6a004be ("[efi] Support the initrd autodetection
mechanism in newer Linux kernels"), this zero-length file will also be
exposed via an EFI_LOAD_FILE2_PROTOCOL instance on a handle with a
fixed device path.
The correct handling of zero-length files via EFI_LOAD_FILE2_PROTOCOL
is unfortunately not well defined.
Linux expects the first call to LoadFile() to always fail with
EFI_BUFFER_TOO_SMALL. When the initrd is genuinely zero-length, iPXE
will return success since the buffer is not too small to hold the
(zero-length) file. This causes Linux to immediately report a
spurious EFI_LOAD_ERROR boot failure.
We could change the logic in iPXE's efi_file_load() to always return
EFI_BUFFER_TOO_SMALL if Buffer is NULL on entry. Since the correct
behaviour of LoadFile() in the corner case of a zero-length file is
left undefined by the UEFI specification, this would be permissible.
Unfortunately this approach would not fix the problem. If we return
EFI_BUFFER_TOO_SMALL and set the file length to zero, then Linux will
call the boot services AllocatePages() method with a zero length. In
at least the EDK2 implementation, this combination of parameters will
cause AllocatePages() to return EFI_OUT_OF_RESOURCES, and Linux will
again report a boot failure.
Another approach would be to install the initrd device path handle
only if we have a non-empty initrd to offer. Unfortunately this would
lead to a failure in yet another corner case: if a previous bootloader
has installed an initrd device path handle (e.g. to pass a boot script
to iPXE) then we must not leave that initrd in place, since then our
loaded kernel would end up seeing the wrong initrd content.
The cleanest fix seems to be to ensure that the initrd device path
handle is installed with the EFI_DEVICE_PATH_PROTOCOL instance present
but with the EFI_LOAD_FILE2_PROTOCOL instance absent (and forcibly
uninstalled if necessary), matching the state in which we leave the
handle after uninstalling our virtual filesystem. Linux will then not
find any handle that supports EFI_LOAD_FILE2_PROTOCOL within the fixed
device path, and so will fall through to trying other mechanisms to
locate the initrd.
Reported-by: Chris Bradshaw <cwbshaw@gmail.com>
Signed-off-by: Michael Brown <mcb30@ipxe.org>
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Commit 7ca801d ("[efi] Use the EFI_RNG_PROTOCOL as an entropy source
if available") added EFI_RNG_PROTOCOL as an alternative entropy source
via an ad-hoc mechanism specific to efi_entropy.c.
Split out EFI_RNG_PROTOCOL to a separate entropy source, and allow the
entropy core to handle the selection of RDRAND, EFI_RNG_PROTOCOL, or
timer ticks as the active source.
The fault detection logic added in commit a87537d ("[efi] Detect and
disable seriously broken EFI_RNG_PROTOCOL implementations") may be
removed completely, since the failure will already be detected by the
generic ANS X9.82-mandated repetition count test and will now be
handled gracefully by the entropy core.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
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Provide per-source state variables for the repetition count test and
adaptive proportion test, to allow for the situation in which an
entropy source can be enabled but then fails during the startup tests,
thereby requiring an alternative entropy source to be used.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
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Signed-off-by: Michael Brown <mcb30@ipxe.org>
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As noted in commit 3c83843 ("[rng] Check for several functioning RTC
interrupts"), experimentation shows that Hyper-V cannot be trusted to
reliably generate RTC interrupts. (As noted in commit f3ba0fb
("[hyperv] Provide timer based on the 10MHz time reference count
MSR"), Hyper-V appears to suffer from a general problem in reliably
generating any legacy interrupts.) An alternative entropy source is
therefore required for an image that may be used in a Hyper-V Gen1
virtual machine.
The x86 RDRAND instruction provides a suitable alternative entropy
source, but may not be supported by all CPUs. We must therefore allow
for multiple entropy sources to be compiled in, with the single active
entropy source selected only at runtime.
Restructure the internal entropy API to allow a working entropy source
to be detected and chosen at runtime.
Enable the RDRAND entropy source for all x86 builds, since it is
likely to be substantially faster than any other source.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
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We currently specify only the iSCSI default value for MaxBurstLength
and ignore any negotiated value, since our internal block device API
allows only for receiving directly into caller-allocated buffers and
so we have no intrinsic limit on burst length.
A conscientious target may however refuse to attempt a transfer that
we request for a number of blocks that would exceed the negotiated
maximum burst length.
Fix by recording the negotiated maximum burst length and using it to
limit the maximum number of blocks per transfer as reported by the
SCSI layer.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
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Signed-off-by: Michael Brown <mcb30@ipxe.org>
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Linux 5.7 added the ability to autodetect an initrd by searching for a
handle via a fixed vendor-specific "Linux initrd device path" and then
locating and using the EFI_LOAD_FILE2_PROTOCOL instance on that
handle.
This maps quite naturally onto our existing concept of a "magic
initrd" as introduced for EFI in commit e5f0255 ("[efi] Provide an
"initrd.magic" file for use by UEFI kernels").
Add an EFI_LOAD_FILE2_PROTOCOL instance to our EFI virtual files
(backed by simply calling the existing EFI_SIMPLE_FILE_SYSTEM_PROTOCOL
method to read from the file), and install the protocol instance for
the "initrd.magic" virtual file onto a new device handle that also
provides the Linux initrd device path.
The design choice in Linux of using a single fixed device path makes
this unfortunately messy to support, since device paths must be unique
within a system. When multiple bootloaders are used (e.g. GRUB
loading iPXE loading Linux) then only one bootloader can ever install
the device path onto a handle. Subsequent bootloaders must locate the
existing handle and replace the load file protocol instance with their
own.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
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Show the requested range when a caller reads from a virtual file via
the EFI_SIMPLE_FILE_SYSTEM_PROTOCOL interface.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
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The Linux kernel bzImage image format and the CPIO archive constructor
will parse the image command line for certain arguments of the form
"key=value". This parsing is currently implemented using strstr() in
a way that can cause a false positive suffix match. For example, a
command line containing "highmem=<n>" would erroneously be treated as
containing a value for "mem=<n>".
Fix by centralising the logic used for parsing such arguments, and
including a check that the argument immediately follows a whitespace
delimiter (or is at the start of the string).
Reported-by: Filippo Giunchedi <filippo@esaurito.net>
Signed-off-by: Michael Brown <mcb30@ipxe.org>
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Commit 74222cd ("[rng] Check for functioning RTC interrupt") added a
check that the RTC is capable of generating interrupts via the legacy
PIC, since this mechanism appears to be broken in some Hyper-V virtual
machines.
Experimentation shows that the RTC is sometimes capable of generating
a single interrupt, but will then generate no subsequent interrupts.
This currently causes rtc_entropy_check() to falsely detect that the
entropy gathering mechanism is functional.
Fix by checking for several RTC interrupts before declaring that it is
a functional entropy source.
Reported-by: Andreas Hammarskjöld <junior@2PintSoftware.com>
Signed-off-by: Michael Brown <mcb30@ipxe.org>
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EISA expansion slot I/O port addresses overlap space that may be
assigned to PCI devices, which can lead to register reads and writes
with unwanted side effects during EISA probing.
Reduce the chances of performing EISA probing on PCI devices by
probing EISA slot vendor and product ID registers only if the EISA
system board vendor ID register indicates that the motherboard
supports EISA.
Debugged-by: Václav Ovsík <vaclav.ovsik@gmail.com>
Tested-by: Václav Ovsík <vaclav.ovsik@gmail.com>
Signed-off-by: Michael Brown <mcb30@ipxe.org>
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Add support for building a LoongArch64 Linux userspace binary.
Signed-off-by: Xiaotian Wu <wuxiaotian@loongson.cn>
Modified-by: Michael Brown <mcb30@ipxe.org>
Signed-off-by: Michael Brown <mcb30@ipxe.org>
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The test suites for the various architectures are often run back to
back, and there is currently nothing to visually distinguish one test
run from another.
Include the architecture name within the self-test startup banner, to
aid in visual identification of test results.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
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Speed up the "Install packages" step for each CI run by caching the
downloaded packages in /var/cache/apt.
Do not include libc6-dbg:i386 within the cache, since apt seems to
complain if asked to download both gcc-aarch64-linux-gnu and
libc6-dbg:i386 at the same time.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
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The PAGE_SHIFT definition is an architectural property, rather than an
aspect of a particular I/O API implementation (of which, in theory,
there may be more than one per architecture).
Reflect this by moving the definition to the top-level bits/io.h for
each architecture.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
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Over the years, the undocumented operand modifier used to produce the
unprefixed constant values in __einfo_error() has varied from "%c0" to
"%a0" in commit 1a77466 ("[build] Fix use of inline assembly on GCC
4.8 ARM64 builds") and back to "%c0" in commit 3fb3ffc ("[build] Fix
use of inline assembly on GCC 8 ARM64 builds"), according to the
evolving demands of the toolchain.
LoongArch64 suffers from a similar issue: GCC 13 will allow either,
but the currently released GCC 12 allows only the "%a0" form.
Introduce a macro ASM_NO_PREFIX, defined in bits/compiler.h, to
abstract away this difference and allow different architectures to use
different operand modifiers.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
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