[efi] Drop to TPL_APPLICATION when gathering entropy
Commit c89a446 ("[efi] Run at TPL_CALLBACK to protect against UEFI
timers") introduced a regression in the EFI entropy gathering code.
When the EFI_RNG_PROTOCOL is not present, we fall back to using timer
interrupts (as for the BIOS build). Since timer interrupts are
disabled at TPL_CALLBACK, WaitForEvent() fails and no entropy can be
gathered.
Fix by dropping to TPL_APPLICATION while entropy gathering is enabled.
Reported-by: Andreas Hammarskjöld <junior@2PintSoftware.com>
Tested-by: Andreas Hammarskjöld <junior@2PintSoftware.com>
Signed-off-by: Michael Brown <mcb30@ipxe.org>
[efi] Run at TPL_CALLBACK to protect against UEFI timers
As noted in the comments, UEFI manages to combines the all of the
worst aspects of both a polling design (inefficiency and inability to
sleep until something interesting happens) and of an interrupt-driven
design (the complexity of code that could be preempted at any time,
thanks to UEFI timers).
This causes problems in particular for UEFI USB keyboards: the
keyboard driver calls UsbAsyncInterruptTransfer() to set up a periodic
timer which is used to poll the USB bus. This poll may interrupt a
critical section within iPXE, typically resulting in list corruption
and either a hang or reboot.
Work around this problem by mirroring the BIOS design, in which we run
with interrupts disabled almost all of the time.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
[xen] Skip probing of any unsupported device types
Xen 4.4 includes the device "device/suspend/event-channel" which does
not have a "backend" key. This currently causes the entire XenBus
device tree probe to fail.
Fix by skipping probe attempts for device types for which there is no
iPXE driver.
Debugged-by: Eytan Heidingsfeld <eytanh@gmail.com>
Signed-off-by: Michael Brown <mcb30@ipxe.org>
[efi] Inhibit our driver Start() method during disconnection attempts
Some HP BIOSes (observed with a Z840) seem to attempt to connect our
drivers in the middle of our call to DisconnectController(). The
precise chain of events is unclear, but the symptom is that we see
several calls to our Supported() and Start() methods, followed by a
system lock-up.
Work around this dubious BIOS behaviour by explicitly failing calls to
our Start() method while we are in the middle of attempting to
disconnect drivers.
Reported-by: Jordan Wright <jordan.m.wright@disney.com>
Debugged-by: Adrian Lucrèce Céleste <adrianlucrececeleste@airmail.cc>
Debugged-by: Christian Nilsson <nikize@gmail.com>
Tested-by: Jordan Wright <jordan.m.wright@disney.com>
Signed-off-by: Michael Brown <mcb30@ipxe.org>
[efi] Continue to connect remaining handles after connection errors
Some UEFI BIOSes will deliberately break the implementation of
ConnectController() to return errors for devices that have been
"disabled" via the BIOS setup screen. (As an added bonus, such BIOSes
may return garbage EFI_STATUS values such as 0xff.)
Work around these broken UEFI BIOSes by ignoring failures and
continuing to attempt to connect any remaining handles.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
[efi] Match behaviour of SnpDxe for truncated received packets
The UEFI specification does not state whether or not a return value of
EFI_BUFFER_TOO_SMALL from the SNP Receive() method should follow the
usual EFI API behaviour of allowing the caller to retry the request
with an increased buffer size.
Examination of the SnpDxe driver in EDK2 suggests that Receive() will
just return the truncated packet (complete with any requested
link-layer header fields), so match this behaviour.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
[efi] Check buffer length for packets retrieved via our SNP protocol
We do not currently check the length of the caller's buffer for
received packets. This creates a potential buffer overrun when iPXE
is being used via the SNP or UNDI protocols.
Fix by checking the buffer length and correctly returning the required
length and an EFI_BUFFER_TOO_SMALL error.
Reported-by: Paul McMillan <paul.mcmillan@oracle.com>
Signed-off-by: Michael Brown <mcb30@ipxe.org>
[efi] Prevent EFI code from being linked in to non-EFI builds
Ensure that efi_systab is an undefined symbol in non-EFI builds. In
particular, this prevents users from incorrectly enabling IMAGE_EFI in
a BIOS build of iPXE.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
Use the PCI bus:dev.fn address in debug messages, falling back to the
EFI handle name only if we do not yet have enough information to
determine the bus:dev.fn address.
Include the vendor and device IDs in debug messages when no suitable
driver is found, to match the diagnostics available in a BIOS
environment.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
[hyperv] Cope with Windows Server 2016 enlightenments
An "enlightened" external bootloader (such as Windows Server 2016's
winload.exe) may take ownership of the Hyper-V connection before all
INT 13 operations have been completed. When this happens, all VMBus
devices are implicitly closed and we are left with a non-functional
network connection.
Detect when our Hyper-V connection has been lost (by checking the
SynIC message page MSR). Reclaim ownership of the Hyper-V connection
and reestablish any VMBus devices, without disrupting any existing
iPXE state (such as IPv4 settings attached to the network device).
Windows Server 2016 will not cleanly take ownership of an active
Hyper-V connection. Experimentation shows that we can quiesce by
resetting only the SynIC message page MSR; this results in a
successful SAN boot (on a Windows 2012 R2 physical host). Choose to
quiesce by resetting (almost) all MSRs, in the hope that this will be
more robust against corner cases such as a stray synthetic interrupt
occurring during the handover.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
[block] Allow use of a non-default EFI SAN boot filename
Some older operating systems (e.g. RHEL6) use a non-default filename
on the root disk and rely on setting an EFI variable to point to the
bootloader. This does not work when performing a SAN boot on a
machine where the EFI variable is not present.
Fix by allowing a non-default filename to be specified via the
"sanboot --filename" option or the "san-filename" setting. For
example:
sanboot --filename \efi\redhat\grub.efi \
iscsi:192.168.0.1::::iqn.2010-04.org.ipxe.demo:rhel6
or
option ipxe.san-filename code 188 = string;
option ipxe.san-filename "\\efi\\redhat\\grub.efi";
option root-path "iscsi:192.168.0.1::::iqn.2010-04.org.ipxe.demo:rhel6";
Originally-implemented-by: Vishvananda Ishaya Abrams <vish.ishaya@oracle.com>
Signed-off-by: Michael Brown <mcb30@ipxe.org>
Describe all SAN devices via ACPI tables such as the iBFT. For tables
that can describe only a single device (i.e. the aBFT and sBFT), one
table is installed per device. For multi-device tables (i.e. the
iBFT), all devices are described in a single table.
An underlying SAN device connection may be closed at the time that we
need to construct an ACPI table. We therefore introduce the concept
of an "ACPI descriptor" which enables the SAN boot code to maintain an
opaque pointer to the underlying object, and an "ACPI model" which can
build tables from a list of such descriptors. This separates the
lifecycles of ACPI descriptions from the lifecycles of the block
device interfaces, and allows for construction of the ACPI tables even
if the block device interface has been closed.
For a multipath SAN device, iPXE will wait until sufficient
information is available to describe all devices but will not wait for
all paths to connect successfully. For example: with a multipath
iSCSI boot iPXE will wait until at least one path has become available
and name resolution has completed on all other paths. We do this
since the iBFT has to include IP addresses rather than DNS names. We
will commence booting without waiting for the inactive paths to either
become available or close; this avoids unnecessary boot delays.
Note that the Linux kernel will refuse to accept an iBFT with more
than two NIC or target structures. We therefore describe only the
NICs that are actually required in order to reach the described
targets. Any iBFT with at most two targets is therefore guaranteed to
describe at most two NICs.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
Add basic support for multipath block devices. The "sanboot" and
"sanhook" commands now accept a list of SAN URIs. We open all URIs
concurrently. The first connection to become available for issuing
block device commands is marked as the active path and used for all
subsequent commands; all other connections are then closed. Whenever
the active path fails, we reopen all URIs and repeat the process.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
Our asprintf() implementation guarantees that strp will be NULL on
allocation failure, but this is not standard behaviour. Detect errors
by checking for a negative return value instead of a NULL pointer.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
[efi] Provide ACPI table description for SAN devices
Provide a basic proof of concept ACPI table description (e.g. iBFT for
iSCSI) for SAN devices in a UEFI environment, using a control flow
that is functionally identical to that used in a BIOS environment.
Originally-implemented-by: Vishvananda Ishaya Abrams <vish.ishaya@oracle.com>
Signed-off-by: Michael Brown <mcb30@ipxe.org>
The concept of the SAN drive number is meaningful only in a BIOS
environment, where it represents the INT13 drive number (0x80 for the
first hard disk). We retain this concept in a UEFI environment to
allow for a simple way for iPXE commands to refer to SAN drives.
Centralise the concept of the default drive number, since it is shared
between all supported environments.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
Allow the active timer (providing udelay() and currticks()) to be
selected at runtime based on probing during the INIT_EARLY stage of
initialisation.
TICKS_PER_SEC is now a fixed compile-time constant for all builds, and
is independent of the underlying clock tick rate. We choose the value
1024 to allow multiplications and divisions on seconds to be converted
to bit shifts.
TICKS_PER_MS is defined as 1, allowing multiplications and divisions
on milliseconds to be omitted entirely. The 2% inaccuracy in this
definition is negligible when using the standard BIOS timer (running
at around 18.2Hz).
TIMER_RDTSC now checks for a constant TSC before claiming to be a
usable timer. (This timer can be tested in KVM via the command-line
option "-cpu host,+invtsc".)
Signed-off-by: Michael Brown <mcb30@ipxe.org>
In some high-end Azure instances (e.g. NC6) we may receive an
unsolicited VMBUS_OFFER_CHANNEL message for a PCIe pass-through device
some time after completing the bus enumeration. This currently causes
apparently random failures due to unexpected VMBus message types.
Fix by ignoring any unsolicited VMBus messages.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
[efi] Work around temporal anomaly encountered during ExitBootServices()
EFI provides no clean way for device drivers to shut down in
preparation for handover to a booted operating system. The platform
firmware simply doesn't bother to call the drivers' Stop() methods.
Instead, drivers must register an EVT_SIGNAL_EXIT_BOOT_SERVICES event
to be signalled when ExitBootServices() is called, and clean up
without any reference to the EFI driver model.
Unfortunately, all timers silently stop working when ExitBootServices()
is called. Even more unfortunately, and for no discernible reason,
this happens before any EVT_SIGNAL_EXIT_BOOT_SERVICES events are
signalled. The net effect of this entertaining design choice is that
any timeout loops on the shutdown path (e.g. for gracefully closing
outstanding TCP connections) may wait indefinitely.
There is no way to report failure from currticks(), since the API
lazily assumes that the host system continues to travel through time
in the usual direction. Work around EFI's violation of this
assumption by falling back to a simple free-running monotonic counter.
Debugged-by: Maor Dickman <maord@mellanox.com>
Signed-off-by: Michael Brown <mcb30@ipxe.org>
The Windows drivers for VMBus devices are enumerated using the
instance UUID rather than the channel number. Include the instance
UUID within the iPXE device name to allow an iPXE network device to be
more easily associated with the corresponding Windows network device
when debugging.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
[efi] Install the HII config access protocol on a child of the SNP handle
In edk2, there are several drivers that associate HII forms (and
corresponding config access protocol instances) with each individual
network device. (In this context, "network device" means the EFI
handle on which the SNP protocol is installed, and on which the device
path ending with the MAC() node is installed also.) Such edk2 drivers
are, for example: Ip4Dxe, HttpBootDxe, VlanConfigDxe.
In UEFI, any given handle can carry at most one instance of a specific
protocol (see e.g. the specification of the InstallProtocolInterface()
boot service). This implies that the class of drivers mentioned above
can't install their EFI_HII_CONFIG_ACCESS_PROTOCOL instances on the
SNP handle directly -- they would conflict with each other.
Accordingly, each of those edk2 drivers creates a "private" child
handle under the SNP handle, and installs its config access protocol
(and corresponding HII package list) on its child handle.
The device path for the child handle is traditionally derived by
appending a Hardware Vendor Device Path node after the MAC() node.
The VenHw() nodes in question consist of a GUID (by definition), and
no trailing data (by choice). The purpose of these VenHw() nodes is
only that all the child nodes can be uniquely identified by device
path.
At the moment iPXE does not follow this pattern. It doesn't run into
a conflict when it installs its EFI_HII_CONFIG_ACCESS_PROTOCOL
directly on the SNP handle, but that's only because iPXE is the sole
driver not following the pattern. This behavior seems risky (one
might call it a "latent bug"); better align iPXE with the edk2 custom.
Cc: Michael Brown <mcb30@ipxe.org>
Cc: Gary Lin <glin@suse.com>
Cc: Ladi Prosek <lprosek@redhat.com>
Ref: http://thread.gmane.org/gmane.comp.bios.edk2.devel/13494/focus=13532
Signed-off-by: Laszlo Ersek <lersek@redhat.com>
Reviewed-by: Ladi Prosek <lprosek@redhat.com>
Modified-by: Michael Brown <mcb30@ipxe.org>
Signed-off-by: Michael Brown <mcb30@ipxe.org>
[efi] Fix uninitialised data in HII IFR structures
The HII IFR structures are allocated via realloc() rather than
zalloc(), and so are not automatically zeroed. This results in the
presence of uninitialised and invalid data, causing crashes elsewhere
in the UEFI firmware.
Fix by explicitly zeroing the newly allocated portion of any IFR
structure in efi_ifr_op().
Debugged-by: Laszlo Ersek <lersek@redhat.com>
Debugged-by: Gary Lin <glin@suse.com>
Signed-off-by: Michael Brown <mcb30@ipxe.org>
[efi] Do not copy garbage bytes into SNP device path MAC address
The SNP device path includes the network device's MAC address within
the MAC_ADDR_DEVICE_PATH.MacAddress field. We check that the
link-layer address will fit within this field, and then perform the
copy using the length of the destination buffer.
At 32 bytes, the MacAddress field is actually larger than the current
maximum iPXE link-layer address. The copy therefore overflows the
source buffer, resulting in trailing garbage bytes being appended to
the device path's MacAddress. This is invisible in debug messages,
since the DevicePathToText protocol will render only the length
implied by the interface type.
Fix by copying only the actual length of the link-layer address (which
we have already verified will not overflow the destination buffer).
Debugged-by: Laszlo Ersek <lersek@redhat.com>
Signed-off-by: Michael Brown <mcb30@ipxe.org>
[pci] Support systems with multiple PCI root bridges
Extend the 16-bit PCI bus:dev.fn address to a 32-bit seg:bus:dev.fn
address, assuming a segment value of zero in contexts where multiple
segments are unsupported by the underlying data structures (e.g. in
the iBFT or BOFM tables).
Signed-off-by: Michael Brown <mcb30@ipxe.org>
[efi] Expose DHCP packets via the Apple NetBoot protocol
Mac OS X uses non-standard EFI protocols to obtain the DHCP packets
from the UEFI firmware.
Originally-implemented-by: Michael Kuron <m.kuron@gmx.de>
Signed-off-by: Michael Brown <mcb30@ipxe.org>
[efi] Use a timer event to generate the currticks() timer
We currently use the EFI_CPU_ARCH_PROTOCOL's GetTimerValue() method to
generate the currticks() timer, calibrated against a 1ms delay from
the boot services Stall() method.
This does not work on ARM platforms, where GetTimerValue() is an empty
stub which just returns EFI_UNSUPPORTED.
Fix by instead creating a periodic timer event, and using this event
to increment a current tick counter.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
The EFI_HII_CONFIG_ACCESS_PROTOCOL's ExtractConfig() method is passed
a request string which includes the parameters being queried plus an
apparently meaningless blob of information (the ConfigHdr), and is
expected to include this same meaningless blob of information in the
results string.
Neither the specification nor the existing EDK2 code (including the
nominal reference implementation in the DriverSampleDxe driver)
provide any reason for the existence of this meaningless blob of
information. It appears to be consumed in its entirety by the
EFI_HII_CONFIG_ROUTING_PROTOCOL, and to contain zero bits of
information by the time it reaches an EFI_HII_CONFIG_ACCESS_PROTOCOL
instance. It would potentially allow for multiple configuration data
sets to be handled by a single EFI_HII_CONFIG_ACCESS_PROTOCOL
instance, in a style alien to the rest of the UEFI specification
(which implicitly assumes that the instance pointer is always
sufficient to uniquely identify the instance).
iPXE currently handles this by simply copying the ConfigHdr from the
request string to the results string, and otherwise ignoring it. This
approach is also used by some code in EDK2, such as OVMF's PlatformDxe
driver.
As of EDK2 commit 8a45f80 ("MdeModulePkg: Make HII configuration
settings available to OS runtime"), this causes an assertion failure
inside EDK2. The failure arises when iPXE is handled a NULL request
string, and responds (as per the specification) with a results string
including all settings. Since there is no meaningless blob to copy
from the request string, there is no corresponding meaningless blob in
the results string. This now causes an assertion failure in
HiiDatabaseDxe's HiiConfigRoutingExportConfig().
The same failure does not affect the OVMF PlatformDxe driver, which
simply passes the request string to the HII BlockToConfig() utility
function. The BlockToConfig() function returns EFI_INVALID_PARAMETER
when passed a null request string, and PlatformDxe propagates this
error directly to the caller.
Fix by matching the behaviour of OVMF's PlatformDxe driver: explicitly
return EFI_INVALID_PARAMETER if the request string is NULL or empty.
This violates the specification (insofar as it is feasible to
determine what the specification actually requires), but causes
correct behaviour with the EDK2 codebase.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
[efi] Provide access to files stored on EFI filesystems
Provide access to local files via the "file://" URI scheme. There are
three syntaxes:
- An opaque URI with a relative path (e.g. "file:script.ipxe").
This will be interpreted as a path relative to the iPXE binary.
- A hierarchical URI with a non-network absolute path
(e.g. "file:/boot/script.ipxe"). This will be interpreted as a
path relative to the root of the filesystem from which the iPXE
binary was loaded.
- A hierarchical URI with a network path in which the authority is a
volume label (e.g. "file://bootdisk/script.ipxe"). This will be
interpreted as a path relative to the root of the filesystem with
the specified volume label.
Note that the potentially desirable shell mappings (e.g. "fs0:" and
"blk0:") are concepts internal to the UEFI shell binary, and do not
seem to be exposed in any way to external executables. The old
EFI_SHELL_PROTOCOL (which did provide access to these mappings) is no
longer installed by current versions of the UEFI shell.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
[efi] Work around broken GetFontInfo() implementations
Several UEFI platforms are known to return EFI_NOT_FOUND when asked to
retrieve the system default font information via GetFontInfo(). Work
around these broken platforms by iterating over the glyphs to find the
maximum height used by a printable character.
Originally-fixed-by: Jonathan Dieter <jdieter@lesbg.com>
Signed-off-by: Michael Brown <mcb30@ipxe.org>
Michael Brown