On some systems (observed with the Thunderbolt ports on a ThinkPad X1
Extreme Gen3 and a ThinkPad P53), if the IOMMU is enabled then the
system firmware will install an ExitBootServices notification event
that disables bus mastering on the Thunderbolt xHCI controller and all
PCI bridges, and destroys any extant IOMMU mappings. This leaves the
xHCI controller unable to perform any DMA operations.
As described in commit 236299b ("[xhci] Avoid DMA during shutdown if
firmware has disabled bus mastering"), any subsequent DMA operation
attempted by the xHCI controller will end up completing after the
operating system kernel has reenabled bus mastering, resulting in a
DMA operation to an area of memory that the hardware is no longer
permitted to access and, on Windows with the Driver Verifier enabled,
a STOP 0xE6 (DRIVER_VERIFIER_DMA_VIOLATION).
That commit avoids triggering any DMA attempts during the shutdown of
the xHCI controller itself. However, this is not a complete solution
since any attached and opened USB device (e.g. a USB NIC) may
asynchronously trigger DMA attempts that happen to occur after bus
mastering has been disabled but before we reset the xHCI controller.
Avoid this problem by installing our own ExitBootServices notification
event at TPL_NOTIFY, thereby causing it to be invoked before the
firmware's own ExitBootServices notification event that disables bus
mastering.
This unsurprisingly causes the shutdown hook itself to be invoked at
TPL_NOTIFY, which causes a fatal error when later code attempts to
raise the TPL to TPL_CALLBACK (which is a lower TPL). Work around
this problem by redefining the "internal" iPXE TPL to be variable, and
set this internal TPL to TPL_NOTIFY when the shutdown hook is invoked.
Avoid calling into an underlying SNP protocol instance from within our
shutdown hook at TPL_NOTIFY, since the underlying SNP driver may
attempt to raise the TPL to TPL_CALLBACK (which would cause a fatal
error). Failing to shut down the underlying SNP device is safe to do
since the underlying device must, in any case, have installed its own
ExitBootServices hook if any shutdown actions are required.
Reported-by: Andreas Hammarskjöld <junior@2PintSoftware.com>
Tested-by: Andreas Hammarskjöld <junior@2PintSoftware.com>
Signed-off-by: Michael Brown <mcb30@ipxe.org>
The EFI loaded image protocol allows an image to be provided with a
custom system table, and we currently use this mechanism to wrap any
boot services calls made by the loaded image in order to provide
strace-like debugging via DEBUG=efi_wrap.
The ExitBootServices() call will modify the global system table,
leaving the loaded image using a system table that is no longer
current. When DEBUG=efi_wrap is used, this generally results in the
machine locking up at the point that the loaded operating system calls
ExitBootServices().
Fix by modifying the global EFI system table to point to our wrapper
functions, instead of providing a custom system table via the loaded
image protocol.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
iPXE decodes any percent-encoded characters during the URI parsing
stage, thereby allowing protocol implementations to consume the raw
field values directly without further decoding.
When reconstructing a URI string for use in an HTTP request line, the
percent-encoding is currently reapplied in a reversible way: we
guarantee that our reconstructed URI string could be decoded to give
the same raw field values.
This technically violates RFC3986, which states that "URIs that differ
in the replacement of a reserved character with its corresponding
percent-encoded octet are not equivalent". Experiments show that
several HTTP server applications will attach meaning to the choice of
whether or not a particular character was percent-encoded, even when
the percent-encoding is unnecessary from the perspective of parsing
the URI into its component fields.
Fix by storing the originally encoded substrings for the path, query,
and fragment fields and using these original encoded versions when
reconstructing a URI string. The path field is also stored as a
decoded string, for use by protocols such as TFTP that communicate
using raw strings rather than URI-encoded strings. All other fields
(such as the username and password) continue to be stored only in
their decoded versions since nothing ever needs to know the originally
encoded versions of these fields.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
Some vendors provide a "system MAC address" within the DSDT/SSDT, to
be used to override the MAC address for a USB docking station.
A full implementation would require an ACPI bytecode interpreter,
since at least one OEM allows the MAC address to be constructed by
executable ACPI bytecode (rather than a fixed data structure).
We instead attempt to extract a plausible-looking "_AUXMAC_#.....#"
string that appears shortly after an "AMAC" or "MACA" signature. This
should work for most implementations encountered in practice.
Debugged-by: Andreas Hammarskjöld <junior@2PintSoftware.com>
Signed-off-by: Michael Brown <mcb30@ipxe.org>
Allow for the DSDT/SSDT signature-scanning and value extraction code
to be reused for extracting a pass-through MAC address.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
Commit cd3de55 ("[efi] Record cached DHCPACK from loaded image's
device handle, if present") added the ability for a chainloaded UEFI
iPXE to reuse an IPv4 address and DHCP options previously obtained by
a built-in PXE stack, without needing to perform a second DHCP
request.
Extend this to also record the cached ProxyDHCPOFFER and PXEBSACK
obtained from the EFI_PXE_BASE_CODE_PROTOCOL instance installed on the
loaded image's device handle, if present.
This allows a chainloaded UEFI iPXE to reuse a boot filename or other
options that were provided via a ProxyDHCP or PXE boot server
mechanism, rather than by standard DHCP.
Tested-by: Andreas Hammarskjöld <junior@2PintSoftware.com>
Signed-off-by: Michael Brown <mcb30@ipxe.org>
When building the Linux userspace binaries, the external system
headers may have already defined values for the __LITTLE_ENDIAN and
__BIG_ENDIAN constants.
Fix by retaining the existing values if already defined, since the
actual values of these constants do not matter.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
The RTL8211B seems to have a bug that prevents the link from coming up
unless the MII_MMD_DATA register is cleared.
The Linux kernel driver applies this workaround (in rtl8211b_resume())
only to the specific RTL8211B PHY model, along with a matching
workaround to set bit 9 of MII_MMD_DATA when suspending the PHY.
Since we have no need to ever suspend the PHY, and since writing a
zero ought to be harmless, we just clear the register unconditionally.
Debugged-by: Nikolay Pertsev <nikolay.p@cos.flag.org>
Tested-by: Nikolay Pertsev <nikolay.p@cos.flag.org>
Signed-off-by: Michael Brown <mcb30@ipxe.org>
Most RNDIS data structures include a trailing 4-byte reserved field.
For the REMOTE_NDIS_PACKET_MSG and REMOTE_NDIS_INITIALIZE_CMPLT
structures, this is an 8-byte field instead.
iPXE currently uses incorrect structure definitions with a 4-byte
reserved field in all data structures, resulting in data payloads that
overlap the last 4 bytes of the 8-byte reserved field.
RNDIS uses explicit offsets to locate any data payloads beyond the
message header, and so liberal RNDIS parsers (such as those used in
Hyper-V and in the Linux USB Ethernet gadget driver) are still able to
parse the malformed structures.
A stricter RNDIS parser (such as that found in some older Android
builds that seem to use an out-of-tree USB Ethernet gadget driver) may
reject the malformed structures since the data payload offset is less
than the header length, causing iPXE to be unable to transmit packets.
Fix by correcting the length of the reserved fields.
Debugged-by: Martin Nield <pmn1492@gmail.com>
Signed-off-by: Michael Brown <mcb30@ipxe.org>
iPXE will construct CPIO headers for images that have a non-empty
command line, thereby allowing raw images (without CPIO headers) to be
injected into a dynamically constructed initrd. This feature is
currently implemented within the BIOS-only bzImage format support.
Split out the CPIO header construction logic to allow for reuse in
other contexts such as in a UEFI build.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
Provide image_extract_exec() as a helper method to allow single-member
archive images (such as gzip compressed images) to be executed without
an explicit "imgextract" step.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
Add the concept of extracting an image from an archive (which could be
a single-file archive such as a gzip-compressed file), along with an
"imgextract" command to expose this functionality to scripts.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
The use of jumbo frames for the Xen netfront virtual NIC requires the
use of scatter-gather ("feature-sg"), with the receive descriptor ring
becoming a list of page-sized buffers and the backend using as many
page buffers as required for each packet.
Since iPXE's abstraction of an I/O buffer does not include any sort of
scatter-gather list, this requires an extra allocation and copy on the
receive datapath for any packet that spans more than a single page.
This support is required in order to successfully boot an AWS EC2
virtual machine (with non-enhanced networking) via iSCSI if jumbo
frames are enabled, since the netback driver used in EC2 seems not to
allow "feature-sg" to be renegotiated once the Linux kernel driver
takes over.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
When CONSOLE_SYSLOG is used, a DBG() from within a network device
driver may cause its transmit() or poll() methods to be unexpectedly
re-entered. Since these methods are not intended to be re-entrant,
this can lead to undefined behaviour.
Add an explicit re-entrancy guard to both methods. Note that this
must operate at a per-netdevice level, since there are legitimate
circumstances under which the netdev_tx() or netdev_poll() functions
may be re-entered (e.g. when using VLAN devices).
Signed-off-by: Michael Brown <mcb30@ipxe.org>
There is no method for obtaining the number of PCI buses when using
PCIAPI_DIRECT, and we therefore currently scan all possible bus
numbers. This can cause a several-second startup delay in some
virtualised environments, since PCI configuration space access will
necessarily require the involvement of the hypervisor.
Ameliorate this situation by defaulting to scanning only a single bus,
and expanding the number of PCI buses to accommodate any subordinate
buses that are detected during enumeration.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
Consumers of acpi_find() will assume that returned structures include
a valid table header and that the length in the table header is
correct. These assumptions are necessary when dealing with raw ACPI
tables, since there exists no independent source of length
information.
Ensure that these assumptions are also valid for ACPI tables read from
sysfs.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
The statx() system call has a clean header file and a consistent
layout, but was unfortunately added only in kernel 4.11.
Using stat() or fstat() directly is extremely messy since glibc does
not necessarily use the kernel native data structures. However, as
the only current use case is to obtain the length of an open file, we
can merely provide a wrapper that does precisely this.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
Add a driver using libslirp to provide a virtual network interface
without requiring root permissions on the host. This simplifies the
process of running iPXE as a Linux userspace application with network
access. For example:
make bin-x86_64-linux/slirp.linux
./bin-x86_64-linux/slirp.linux --net slirp
libslirp will provide a built-in emulated DHCP server and NAT router.
Settings such as the boot filename may be controlled via command-line
options. For example:
./bin-x86_64-linux/slirp.linux \
--net slirp,filename=http://192.168.0.1/boot.ipxe
Signed-off-by: Michael Brown <mcb30@ipxe.org>
The ACPI API currently expects platforms to provide access to a single
contiguous ACPI table. Some platforms (e.g. Linux userspace) do not
provide a convenient way to obtain the entire ACPI table, but do
provide access to individual tables.
All iPXE consumers of the ACPI API require access only to individual
tables.
Redefine the internal API to make acpi_find() an API method, with all
existing implementations delegating to the current RSDT-based
implementation.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
When building as a Linux userspace application, iPXE currently
implements its own system calls to the host kernel rather than relying
on the host's C library. The output binary is statically linked and
has no external dependencies.
This matches the general philosophy of other platforms on which iPXE
runs, since there are no external libraries available on either BIOS
or UEFI bare metal. However, it would be useful for the Linux
userspace application to be able to link against host libraries such
as libslirp.
Modify the build process to perform a two-stage link: first picking
out the requested objects in the usual way from blib.a but with
relocations left present, then linking again with a helper object to
create a standard hosted application. The helper object provides the
standard main() entry point and wrappers for the Linux system calls
required by the iPXE Linux drivers and interface code.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
Record the cached DHCPACK obtained from the EFI_PXE_BASE_CODE_PROTOCOL
instance installed on the loaded image's device handle, if present.
This allows a chainloaded UEFI iPXE to reuse the IPv4 address and DHCP
options previously obtained by the built-in PXE stack, as is already
done for a chainloaded BIOS iPXE.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
The "autoboot device" and "autoexec script" functionalities in
efi_autoboot.c are unrelated except in that they both need to be
invoked by efiprefix.c before device drivers are loaded.
Split out the autoexec script portions to a separate file to avoid
potential confusion.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
Split out the portions of cachedhcp.c that can be shared between BIOS
and UEFI (both of which can provide a buffer containing a previously
obtained DHCP packet, and neither of which provide a means to
determine the length of this DHCP packet).
Signed-off-by: Michael Brown <mcb30@ipxe.org>
The semantics of the assembler's .align directive vary by CPU
architecture. For the ARM builds, it specifies a power of two rather
than a number of bytes. This currently leads to the .einfo entries
(which do not appear in the final binary) having an alignment of 256
bytes for the ARM builds.
Fix by switching to the GNU-specific directive .balign, which is
consistent across architectures
Signed-off-by: Michael Brown <mcb30@ipxe.org>
Support for building with the Intel C compiler (icc) was added in 2009
in the expectation that UEFI support would eventually involve
compiling iPXE to EFI Byte Code.
EFI Byte Code has never found any widespread use: no widely available
compilers can emit it, Microsoft refuses to sign EFI Byte Code
binaries for UEFI Secure Boot, and I have personally never encountered
any examples of EFI Byte Code in the wild.
The support for using the Intel C compiler has not been tested in over
a decade, and would almost certainly require modification to work with
current releases of the compiler.
Simplify the build process by removing this old legacy code.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
Require drivers to report the total number of Infiniband ports. This
is necessary to report the correct number of ports on devices with
dynamic port types.
For example, dual-port Mellanox cards configured for (eth, ib) would
be rejected by the subnet manager, because they report using "port 2,
out of 1".
Signed-off-by: Christian Iversen <ci@iversenit.dk>
When booting iPXE from a filesystem (e.g. a FAT-formatted USB key) it
can be useful to have an iPXE script loaded automatically from the
same filesystem. Compared to using an embedded script, this has the
advantage that the script can be edited without recompiling the iPXE
binary.
For the BIOS version of iPXE, loading from a filesystem is handled
using syslinux (or isolinux) which allows the script to be passed to
the iPXE .lkrn image as an initrd.
For the UEFI version of iPXE, the platform firmware loads the iPXE
.efi image directly and there is currently no equivalent of the BIOS
initrd mechanism.
Add support for automatically loading a file "autoexec.ipxe" (if
present) from the root of the filesystem containing the UEFI iPXE
binary.
A combined BIOS and UEFI image for a USB key can be created using e.g.
./util/genfsimg -o usbkey.img -s myscript.ipxe \
bin-x86_64-efi/ipxe.efi bin/ipxe.lkrn
The file "myscript.ipxe" would appear as "autoexec.ipxe" on the USB
key, and would be loaded automatically on both BIOS and UEFI systems.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
Consolidate the remaining logic common to initrd_init() and imgmem()
into a shared image_memory() function.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
Provide the "imgmem" command to create an image from an existing block
of memory, for debugging purposes only.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
A switch port using 802.1x authentication will send EAP
Request-Identity packets once the physical link is up, and will not be
forwarding packets until the port identity has been established.
We do not currently support 802.1x authentication. However, a
reasonably common configuration involves using a preset list of
permitted MAC addresses, with the "authentication" taking place
between the switch and a RADIUS server. In this configuration, the
end device does not need to perform any authentication step, but does
need to be prepared for the switch port to fail to forward packets for
a substantial time after physical link-up. This exactly matches the
"blocked link" semantics already used when detecting a non-forwarding
switch port via LACP or STP.
Treat a received EAP Request-Identity as indicating a blocked link.
Unlike LACP or STP, there is no way to determine the expected time
until the next EAP packet and so we must choose a fixed timeout.
Erroneously assuming that the link is blocked is relatively harmless
since we will still attempt to transmit and receive data even over a
link that is marked as blocked, and so the net effect is merely to
prolong DHCP attempts. In contrast, erroneously assuming that the
link is unblocked will potentially cause DHCP to time out and give up,
resulting in a failed boot.
The default EAP Request-Identity interval in Cisco switches (where
this is most likely to be encountered in practice) is 30 seconds, so
choose 45 seconds as a timeout that is likely to avoid gaps during
which we falsely assume that the link is unblocked.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
Replace the GPL2+-only EAPoL code (currently used only for WPA) with
new code licensed under GPL2+-or-UBDL.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
There may be multiple instances of EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL for
a single PCI segment. Use the bus number range descriptor from the
ACPI resource list to identify the correct protocol instance.
There is some discrepancy between the ACPI and UEFI specifications
regarding the interpretation of values within the ACPI resource list.
The ACPI specification defines the min/max field values to be within
the secondary (device-side) address space, and defines the offset
field value as "the offset that must be added to the address on the
secondary side to obtain the address on the primary side".
The UEFI specification states instead that the offset field value is
the "offset to apply to the starting address to convert it to a PCI
address", helpfully omitting to clarify whether "to apply" in this
context means "to add" or "to subtract". The implication of the
wording is also that the "starting address" is not already a "PCI
address" and must therefore be a host-side address rather than the
ACPI-defined device-side address.
Code comments in the EDK2 codebase seem to support the latter
(non-ACPI) interpretation of these ACPI structures. For example, in
the PciHostBridgeDxe driver there can be found the comment
Macros to translate device address to host address and vice versa.
According to UEFI 2.7, device address = host address + translation
offset.
along with a pair of macros TO_HOST_ADDRESS() and TO_DEVICE_ADDRESS()
which similarly negate the sense of the "translation offset" from the
definition found in the ACPI specification.
The existing logic in efipci_ioremap() (based on a presumed-working
externally contributed patch) applies the non-ACPI interpretation: it
assumes that min/max field values are host-side addresses and that the
offset field value is negated.
Match this existing logic by assuming that min/max field values are
host-side bus numbers. (The bus number offset value is therefore not
required and so can be ignored.)
As noted in commit 9b25f6e ("[efi] Fall back to assuming identity
mapping of MMIO address space"), some systems seem to fail to provide
MMIO address space descriptors. Assume that some systems may
similarly fail to provide bus number range descriptors, and fall back
in this situation to assuming that matching on segment number alone is
sufficient.
Testing any of this is unfortunately impossible without access to
esoteric hardware that actually uses non-zero translation offsets.
Originally-implemented-by: Thomas Walker <twalker@twosigma.com>
Signed-off-by: Michael Brown <mcb30@ipxe.org>
USB tethering via an iPhone is unreasonably complicated due to the
requirement to perform a pairing operation that involves establishing
a TLS session over a completely unrelated USB function that speaks a
protocol that is almost, but not quite, entirely unlike TCP.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
Michael Brown
Aaron Young
Christian Iversen