Commit Graph

971 Commits (8e478e648fb68ac6f07e4e5cd80a5c1fefcb1cf5)

Author SHA1 Message Date
Michael Brown 8e478e648f [crypto] Allow initialisation vector length to vary from cipher blocksize
Signed-off-by: Michael Brown <mcb30@ipxe.org>
2022-10-25 13:21:28 +01:00
Michael Brown 52f72d298a [crypto] Expose null crypto algorithm methods for reuse
Signed-off-by: Michael Brown <mcb30@ipxe.org>
2022-10-25 13:20:22 +01:00
Michael Brown 2c78242732 [tls] Add support for DHE variants of the existing cipher suites
Signed-off-by: Michael Brown <mcb30@ipxe.org>
2022-10-11 15:42:13 +01:00
Michael Brown 6b2c94d3a7 [tls] Add support for Ephemeral Diffie-Hellman key exchange
Signed-off-by: Michael Brown <mcb30@ipxe.org>
2022-10-11 15:42:11 +01:00
Michael Brown ea33ea33c0 [tls] Add key exchange mechanism to definition of cipher suite
Allow for the key exchange mechanism to vary depending upon the
selected cipher suite.

Signed-off-by: Michael Brown <mcb30@ipxe.org>
2022-10-11 14:37:12 +01:00
Michael Brown 80c45c5c71 [tls] Record ServerKeyExchange record, if provided
Accept and record the ServerKeyExchange record, which is required for
key exchange mechanisms such as Ephemeral Diffie-Hellman (DHE).

Signed-off-by: Michael Brown <mcb30@ipxe.org>
2022-10-11 14:37:12 +01:00
Michael Brown 028aac99a3 [tls] Generate pre-master secret at point of sending ClientKeyExchange
The pre-master secret is currently constructed at the time of
instantiating the TLS connection.  This precludes the use of key
exchange mechanisms such as Ephemeral Diffie-Hellman (DHE), which
require a ServerKeyExchange message to exchange additional key
material before the pre-master secret can be constructed.

Allow for the use of such cipher suites by deferring generation of the
master secret until the point of sending the ClientKeyExchange
message.

Signed-off-by: Michael Brown <mcb30@ipxe.org>
2022-10-11 14:37:12 +01:00
Michael Brown 18b861024a [crypto] Add Ephemeral Diffie-Hellman key exchange algorithm
Add an implementation of the Ephemeral Diffie-Hellman key exchange
algorithm as defined in RFC2631, with test vectors taken from the NIST
Cryptographic Toolkit.

Signed-off-by: Michael Brown <mcb30@ipxe.org>
2022-10-11 14:33:19 +01:00
Michael Brown 007d3cb800 [crypto] Simplify internal HMAC API
Simplify the internal HMAC API so that the key is provided only at the
point of calling hmac_init(), and the (potentially reduced) key is
stored as part of the context for later use by hmac_final().

This simplifies the calling code, and avoids the need for callers such
as TLS to allocate a potentially variable length block in order to
retain a copy of the unmodified key.

Signed-off-by: Michael Brown <mcb30@ipxe.org>
2022-10-10 12:21:54 +01:00
Michael Brown 3aa6b79c8d [pci] Add minimal PCI bridge driver
Add a minimal driver for PCI bridges that can be used to locate the
bridge to which a PCI device is attached.

Signed-off-by: Michael Brown <mcb30@ipxe.org>
2022-09-19 17:47:57 +01:00
Michael Brown 649176cd60 [pci] Select PCI I/O API at runtime for cloud images
Pretty much all physical machines and off-the-shelf virtual machines
will provide a functional PCI BIOS.  We therefore default to using
only the PCI BIOS, with no fallback to an alternative mechanism if the
PCI BIOS fails.

AWS EC2 provides the opportunity to experience some exceptions to this
rule.  For example, the t3a.nano instances in eu-west-1 have no
functional PCI BIOS at all.  As of commit 83516ba ("[cloud] Use
PCIAPI_DIRECT for cloud images") we therefore use direct Type 1
configuration space accesses in the images built and published for use
in the cloud.

Recent experience has discovered yet more variation in AWS EC2
instances.  For example, some of the metal instance types have
multiple PCI host bridges and the direct Type 1 accesses therefore
see only a subset of the PCI devices.

Attempt to accommodate future such variations by making the PCI I/O
API selectable at runtime and choosing ECAM (if available), falling
back to the PCI BIOS (if available), then finally falling back to
direct Type 1 accesses.

This is implemented as a dedicated PCIAPI_CLOUD API, rather than by
having the PCI core select a suitable API at runtime (as was done for
timers in commit 302f1ee ("[time] Allow timer to be selected at
runtime").  The common case will remain that only the PCI BIOS API is
required, and we would prefer to retain the optimisations that come
from inlining the configuration space accesses in this common case.
Cloud images are (at present) disk images rather than ROM images, and
so the increased code size required for this design approach in the
PCIAPI_CLOUD case is acceptable.

Signed-off-by: Michael Brown <mcb30@ipxe.org>
2022-09-18 13:41:21 +01:00
Michael Brown be667ba948 [pci] Add support for the Enhanced Configuration Access Mechanism (ECAM)
The ACPI MCFG table describes a direct mapping of PCI configuration
space into MMIO space.  This mapping allows access to extended
configuration space (up to 4096 bytes) and also provides for the
existence of multiple host bridges.

Add support for the ECAM mechanism described by the ACPI MCFG table,
as a selectable PCI I/O API alongside the existing PCI BIOS and Type 1
mechanisms.

Signed-off-by: Michael Brown <mcb30@ipxe.org>
2022-09-16 01:05:47 +01:00
Michael Brown ff228f745c [pci] Generalise pci_num_bus() to pci_discover()
Allow pci_find_next() to discover devices beyond the first PCI
segment, by generalising pci_num_bus() (which implicitly assumes that
there is only a single PCI segment) with pci_discover() (which has the
ability to return an arbitrary contiguous chunk of PCI bus:dev.fn
address space).

Signed-off-by: Michael Brown <mcb30@ipxe.org>
2022-09-15 16:49:47 +01:00
Michael Brown 56b30364c5 [pci] Check for wraparound in callers of pci_find_next()
The semantics of the bus:dev.fn parameter passed to pci_find_next()
are "find the first existent PCI device at this address or higher",
with the caller expected to increment the address between finding
devices.  This does not allow the parameter to distinguish between the
two cases "start from address zero" and "wrapped after incrementing
maximal possible address", which could therefore lead to an infinite
loop in the degenerate case that a device with address ffff:ff:1f.7
really exists.

Fix by checking for wraparound in the caller (which is already
responsible for performing the increment).

Signed-off-by: Michael Brown <mcb30@ipxe.org>
2022-09-15 15:20:58 +01:00
Michael Brown 8fc3c26eae [pci] Allow pci_find_next() to return non-zero PCI segments
Separate the return status code from the returned PCI bus:dev.fn
address, in order to allow pci_find_next() to be used to find devices
with a non-zero PCI segment number.

Signed-off-by: Michael Brown <mcb30@ipxe.org>
2022-09-15 15:20:58 +01:00
Michael Brown cad1cc6b44 [intelxl] Add driver for Intel 100 Gigabit Ethernet NICs
Add a driver for the E810 family of 100 Gigabit Ethernet NICs.  The
core datapath is identical to that of the 40 Gigabit XL710, and this
part of the code is shared between both drivers.  The admin queue
mechanism is sufficiently similar to make it worth reusing substantial
portions of the code, with separate implementations for several
commands to handle the (unnecessarily) breaking changes in data
structure layouts.  The major differences are in the mechanisms for
programming queue contexts (where the E810 abandons TX/RX symmetry)
and for configuring the transmit scheduler and receive filters: these
portions are sufficiently different to justify a separate driver.

Signed-off-by: Michael Brown <mcb30@ipxe.org>
2022-08-12 16:15:17 +01:00
Michael Brown 0965cec53c [pci] Generalise function-level reset mechanism
Signed-off-by: Michael Brown <mcb30@ipxe.org>
2022-08-08 16:39:40 +01:00
Michael Brown 1e1b9593e6 [linux] Add stub phys_to_user() implementation
For symmetry with the stub user_to_phys() implementation, provide
phys_to_user() with the same underlying assumption that virtual
addresses are physical (since there is no way to know the real
physical address when running as a Linux userspace executable).

Signed-off-by: Michael Brown <mcb30@ipxe.org>
2022-03-24 12:58:52 +00:00
Michael Brown 27825e5557 [acpi] Allow for the possibility of overriding ACPI tables at link time
Allow for linked-in code to override the mechanism used to locate an
ACPI table, thereby opening up the possibility of ACPI self-tests.

Signed-off-by: Michael Brown <mcb30@ipxe.org>
2022-03-24 12:58:52 +00:00
Michael Brown ba93c9134c [fbcon] Support Unicode character output
Accumulate UTF-8 characters in fbcon_putchar(), and require the frame
buffer console's .glyph() method to accept Unicode character values.

Signed-off-by: Michael Brown <mcb30@ipxe.org>
2022-03-15 17:27:18 +00:00
Michael Brown 3cd3a73261 [utf8] Add ability to accumulate Unicode characters from UTF-8 bytes
Signed-off-by: Michael Brown <mcb30@ipxe.org>
2022-03-01 15:57:33 +00:00
Michael Brown 304333dace [console] Support changing keyboard map at runtime
Provide the special keyboard map named "dynamic" which allows the
active keyboard map to be selected at runtime via the ${keymap}
setting, e.g.:

  #define KEYBOARD_MAP dynamic

  iPXE> set keymap uk

Signed-off-by: Michael Brown <mcb30@ipxe.org>
2022-02-16 14:06:33 +00:00
Michael Brown 11e17991d0 [console] Ensure that US keyboard map appears at start of linker table
Signed-off-by: Michael Brown <mcb30@ipxe.org>
2022-02-16 13:50:41 +00:00
Michael Brown e1cedbc0d4 [console] Support AltGr to access ASCII characters via remapping
Several keyboard layouts define ASCII characters as accessible only
via the AltGr modifier.  Add support for this modifier to ensure that
all ASCII characters are accessible.

Experiments suggest that the BIOS console is likely to fail to
generate ASCII characters when the AltGr key is pressed.  Work around
this limitation by accepting LShift+RShift (which will definitely
produce an ASCII character) as a synonym for AltGr.

Signed-off-by: Michael Brown <mcb30@ipxe.org>
2022-02-15 12:50:26 +00:00
Michael Brown f2a59d5973 [console] Centralise handling of key modifiers
Handle Ctrl and CapsLock key modifiers within key_remap(), to provide
consistent behaviour across different console types.

Signed-off-by: Michael Brown <mcb30@ipxe.org>
2022-02-15 11:58:50 +00:00
Michael Brown 871dd236d4 [console] Allow for named keyboard mappings
Separate the concept of a keyboard mapping from a list of remapped
keys, to allow for the possibility of supporting multiple keyboard
mappings at runtime.

Signed-off-by: Michael Brown <mcb30@ipxe.org>
2022-02-15 11:58:47 +00:00
Michael Brown 1150321595 [tables] Add ability to declare static table start and end markers
The compound statement expression within __table_entries() prevents
the use of top-level declarations such as

  static struct thing *things = table_start ( THINGS );

Define TABLE_START() and TABLE_END() macros that can be used as:

  static TABLE_START ( things_start, THINGS );
  static struct thing *things = things_start;

Signed-off-by: Michael Brown <mcb30@ipxe.org>
2022-02-14 13:21:09 +00:00
Michael Brown 0bbd896783 [console] Handle remapping of scancode 86
The key with scancode 86 appears in the position between left shift
and Z on a US keyboard, where it typically fails to exist entirely.
Most US keyboard maps define this nonexistent key as generating "\|",
with the notable exception of "loadkeys" which instead reports it as
generating "<>".  Both of these mapping choices duplicate keys that
exist elsewhere in the map, which causes problems for our ASCII-based
remapping mechanism.

Work around these quirks by treating the key as generating "\|" with
the high bit set, and making it subject to remapping.  Where the BIOS
generates "\|" as expected, this allows us to remap to the correct
ASCII value.

Signed-off-by: Michael Brown <mcb30@ipxe.org>
2022-02-10 13:59:32 +00:00
Michael Brown f51a62bc3f [console] Generalise bios_keymap() as key_remap()
Allow the keyboard remapping functionality to be exposed to consoles
other than the BIOS console.

Signed-off-by: Michael Brown <mcb30@ipxe.org>
2022-02-10 13:11:27 +00:00
Michael Brown f4f9adf618 [efi] Include Secure Boot Advanced Targeting (SBAT) metadata
SBAT defines an encoding for security generation numbers stored as a
CSV file within a special ".sbat" section in the signed binary.  If a
Secure Boot exploit is discovered then the generation number will be
incremented alongside the corresponding fix.

Platforms may then record the minimum generation number required for
any given product.  This allows for an efficient revocation mechanism
that consumes minimal flash storage space (in contrast to the DBX
mechanism, which allows for only a single-digit number of revocation
events to ever take place across all possible signed binaries).

Add SBAT metadata to iPXE EFI binaries to support this mechanism.

Signed-off-by: Michael Brown <mcb30@ipxe.org>
2022-01-13 14:12:44 +00:00
Michael Brown 53a5de3641 [doc] Update user-visible ipxe.org URIs to use HTTPS
Signed-off-by: Michael Brown <mcb30@ipxe.org>
2022-01-13 12:48:38 +00:00
Michael Brown f43c2fd697 [settings] Support formatting UUIDs as little-endian GUIDs
The RFC4122 specification defines UUIDs as being in network byte
order, but an unfortunately significant amount of (mostly Microsoft)
software treats them as having the first three fields in little-endian
byte order.

In an ideal world, any server-side software that compares UUIDs for
equality would perform an endian-insensitive comparison (analogous to
comparing strings for equality using a case-insensitive comparison),
and would therefore not care about byte order differences.

Define a setting type name ":guid" to allow a UUID setting to be
formatted in little-endian order, to simplify interoperability with
server-side software that expects such a formatting.

Signed-off-by: Michael Brown <mcb30@ipxe.org>
2022-01-04 14:03:12 +00:00
Michael Brown 562c74e1ea [efi] Run ExitBootServices shutdown hook at TPL_NOTIFY
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>
2021-11-23 15:55:01 +00:00
Michael Brown b6045a8cbb [efi] Modify global system table when wrapping a loaded image
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>
2021-11-21 13:34:10 +00:00
Michael Brown 1844aacc83 [uri] Retain original encodings for path, query, and fragment fields
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>
2021-11-12 09:58:29 +00:00
Aaron Young f24a2794e1 [virtio] Update driver to use DMA API
Signed-off-by: Aaron Young <aaron.young@oracle.com>
2021-10-28 13:19:30 +01:00
Michael Brown 0cc4c42f0a [acpi] Allow for extraction of a MAC address from the DSDT/SSDT
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>
2021-09-09 12:18:00 +01:00
Michael Brown 02ec659b73 [acpi] Generalise DSDT/SSDT data extraction logic
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>
2021-09-08 14:46:30 +01:00
Michael Brown e09e1142a3 [efi] Record cached ProxyDHCPOFFER and PXEBSACK, if present
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>
2021-07-27 13:50:36 +01:00
Michael Brown 4aa0375821 [rdc] Add driver for RDC R6040 embedded NIC
Signed-off-by: Michael Brown <mcb30@ipxe.org>
2021-06-28 12:32:19 +01:00
Michael Brown 92807f5759 [rndis] Fix size of reserved fields
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>
2021-06-07 12:01:10 +01:00
Michael Brown bfca3db41e [cpio] Split out bzImage initrd CPIO header construction
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>
2021-05-21 15:19:38 +01:00
Michael Brown 191f8825cb [image] Allow single-member archive images to be executed transparently
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>
2021-05-12 13:57:35 +01:00
Michael Brown 866fa1ce76 [gzip] Add support for gzip archive images
Signed-off-by: Michael Brown <mcb30@ipxe.org>
2021-05-08 15:34:19 +01:00
Michael Brown d093683d93 [zlib] Add support for zlib archive images
Signed-off-by: Michael Brown <mcb30@ipxe.org>
2021-05-08 15:34:19 +01:00
Michael Brown 5c9c8d2b9b [image] Add "imgextract" command for extracting archive images
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>
2021-05-08 15:34:19 +01:00
Michael Brown de4f31cdca [image] Provide image_set_len() utility function
Signed-off-by: Michael Brown <mcb30@ipxe.org>
2021-05-08 15:34:19 +01:00
Michael Brown 85d179f2c6 [xen] Support scatter-gather to allow for jumbo frames
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>
2021-04-14 16:33:41 +01:00
Michael Brown 78749542fc [netdevice] Ensure driver transmit() and poll() will not be re-entered
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>
2021-04-10 16:53:52 +01:00
Michael Brown 0be8491b71 [pci] Avoid scanning nonexistent buses when using PCIAPI_DIRECT
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>
2021-04-10 15:05:05 +01:00