Commit Graph

446 Commits (80c45c5c71af76e4313c37528d29aa485b247073)

Author SHA1 Message Date
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 6459e3b7b1 [linux] Add missing PROVIDE_PCIAPI_INLINE() macros
Ensure type consistency of the PCI I/O API methods by adding the
missing PROVIDE_PCIAPI_INLINE() macros.

Signed-off-by: Michael Brown <mcb30@ipxe.org>
2022-09-15 15:20:58 +01:00
Michael Brown dd35475438 [efi] Support Unicode character output via framebuffer console
Extend the glyph cache to include a number of dynamic entries that are
populated on demand whenever a non-ASCII character needs to be drawn.

Signed-off-by: Michael Brown <mcb30@ipxe.org>
2022-03-15 17:30:52 +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 2ff3385e00 [efi] Support Unicode character output via text console
Signed-off-by: Michael Brown <mcb30@ipxe.org>
2022-03-15 17:09:58 +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 0979b3a11d [efi] Support keyboard remapping via the EFI console
Signed-off-by: Michael Brown <mcb30@ipxe.org>
2022-02-10 13:11:27 +00:00
Michael Brown 6ba671acd9 [efi] Attempt to fetch autoexec script via TFTP
Attempt to fetch the autoexec.ipxe script via TFTP using the PXE base
code protocol installed on the loaded image's device handle, if
present.

This provides a generic alternative to the use of an embedded script
for chainloaded binaries, which is particularly useful in a UEFI
Secure Boot environment since it allows the script to be modified
without the need to sign a new binary.

As a side effect, this also provides a third method for breaking the
PXE chainloading loop (as an alternative to requiring an embedded
script or custom DHCP server configuration).

Signed-off-by: Michael Brown <mcb30@ipxe.org>
2022-01-18 13:16:12 +00:00
Michael Brown ec746c0001 [efi] Allow for autoexec scripts that are not located in a filesystem
Signed-off-by: Michael Brown <mcb30@ipxe.org>
2022-01-18 13:16:12 +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 9062544f6a [efi] Disable EFI watchdog timer when shutting down to boot an OS
The UEFI specification mandates that the EFI watchdog timer should be
disabled by the platform firmware as part of the ExitBootServices()
call, but some platforms (e.g. Hyper-V) are observed to occasionally
forget to do so, resulting in a reboot approximately five minutes
after starting the operating system.

Work around these firmware bugs by disabling the watchdog timer
ourselves.

Requested-by: Andreas Hammarskjöld <junior@2PintSoftware.com>
Tested-by: Andreas Hammarskjöld <junior@2PintSoftware.com>
Signed-off-by: Michael Brown <mcb30@ipxe.org>
2021-11-25 09:30:59 +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 a046da21a4 [efi] Raise TPL during driver unload entry point
The efi_unload() function is currently missing the calls to raise and
restore the TPL.  This has the side effect of causing iPXE to return
from the driver unload entry point at TPL_CALLBACK, which will cause
unexpected behaviour (typically a system lockup) shortly afterwards.

Fix by adding the missing calls to raise and restore the TPL.

Debugged-by: Petr Borsodi <petr.borsodi@gmail.com>
Signed-off-by: Michael Brown <mcb30@ipxe.org>
2021-11-22 12:50:38 +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 51612b6e69 [efi] Do not attempt to use console output after ExitBootServices()
A successful call to ExitBootServices() will result in the EFI console
becoming unusable.  Ensure that the EFI wrapper produces a complete
line of debug output before calling the wrapped ExitBootServices()
method, and attempt subsequent debug output only if the call fails.

Signed-off-by: Michael Brown <mcb30@ipxe.org>
2021-11-21 13:24:24 +00:00
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 3c040ad387 [efi] Veto the Itautec Ip4ConfigDxe driver
The Ip4ConfigDxe driver bug that was observed on Dell systems in
commit 64b4452 ("[efi] Blacklist the Dell Ip4ConfigDxe driver") has
also been observed on systems with a manufacturer name of "Itautec
S.A.".  The symptoms of the bug are identical: an attempt to call
DisconnectController() on the LOM device handle will lock up the
system.

Fix by extending the veto to cover the Ip4ConfigDxe driver for this
manufacturer.

Debugged-by: Celso Viana <celso.vianna@gmail.com>
Signed-off-by: Michael Brown <mcb30@ipxe.org>
2021-06-11 15:14:21 +01:00
Michael Brown e5f0255173 [efi] Provide an "initrd.magic" file for use by UEFI kernels
Provide a file "initrd.magic" via the EFI_SIMPLE_FILE_SYSTEM_PROTOCOL
that contains the initrd file as constructed for BIOS bzImage kernels
(including injected files with CPIO headers constructed by iPXE).

This allows BIOS and UEFI kernels to obtain the exact same initramfs
image, by adding "initrd=initrd.magic" to the kernel command line.
For example:

  #!ipxe
  kernel boot/vmlinuz initrd=initrd.magic
  initrd boot/initrd.img
  initrd boot/modules/e1000.ko      /lib/modules/e1000.ko
  initrd boot/modules/af_packet.ko  /lib/modules/af_packet.ko
  boot

Do not include the "initrd.magic" file within the root directory
listing, since doing so would break software such as wimboot that
processes all files within the root directory.

Signed-off-by: Michael Brown <mcb30@ipxe.org>
2021-05-21 20:18:50 +01:00
Michael Brown ef9953b712 [efi] Allow for non-image-backed virtual files
Restructure the EFI_SIMPLE_FILE_SYSTEM_PROTOCOL implementation to
allow for the existence of virtual files that are not simply backed by
a single underlying image.

Signed-off-by: Michael Brown <mcb30@ipxe.org>
2021-05-21 16:32:36 +01:00
Michael Brown 56f7d44fde [efi] Show ACPI address space descriptor ranges in debug messages
Signed-off-by: Michael Brown <mcb30@ipxe.org>
2021-04-21 16:13:02 +01:00
Michael Brown 3efdbef2f0 [efi] Always map full length of coherent DMA buffer allocation
The EFI PCI API takes a page count as the input to AllocateBuffer()
but a byte count as the input to Map().  There is nothing in the UEFI
specification that requires us to map exactly the allocated length,
and no systems have yet been observed that will fail if the map length
does not exactly match the allocated length.  However, it is plausible
that some implementations may fail if asked to map a length that does
not match the length of the corresponding allocation.

Avoid potential future problems by always mapping the full allocated
length.

Signed-off-by: Michael Brown <mcb30@ipxe.org>
2021-04-20 14:37:08 +01:00
Michael Brown 614d99eba1 [xen] Avoid infinite loop on allocation failure in xenstore_response()
Signed-off-by: Michael Brown <mcb30@ipxe.org>
2021-04-20 13:28:57 +01:00
Michael Brown 7c8fc2cae8 [linux] Fail at link time if building slirp.linux without libslirp
The iPXE build system is constructed for a standalone codebase with no
external dependencies, and does not have any equivalent of the
standard userspace ./configure script.  We currently check for the
ability to include slirp/libslirp.h and conditionalise portions of
linux_api.c on its presence.  The actual slirp driver code is built
unconditionally, as with all iPXE drivers.

This currently leads to a silent runtime failure if attempting to use
slirp.linux built on a system that was missing slirp/libslirp.h.

Convert this to a link-time failure by deliberately omitting the
relevant symbols from linux_api.c when slirp/libslirp.h is not
present.  This allows other builds (e.g. tap.linux or tests.linux) to
succeed: the link-time failure will occur only if the slirp driver is
included within the build target.

Signed-off-by: Michael Brown <mcb30@ipxe.org>
2021-03-11 15:25:33 +00:00
Michael Brown 65bd5c05db [linux] Do not assume that stat() works on sysfs files
Linux kernel 3.12 and earlier report a zero size via stat() for all
ACPI table files in sysfs.  There is no way to determine the file size
other than by reading the file until EOF.

Signed-off-by: Michael Brown <mcb30@ipxe.org>
2021-03-03 02:26:42 +00:00
Michael Brown 1c4917b6a7 [linux] Validate length of ACPI table read from sysfs
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>
2021-03-03 01:55:07 +00:00
Michael Brown 69ecab2634 [linux] Use fstat() rather than statx()
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>
2021-03-03 01:01:58 +00:00
Michael Brown 2a2909cd1f [linux] Use generic sysfs mechanism to read SMBIOS table
Signed-off-by: Michael Brown <mcb30@ipxe.org>
2021-03-02 23:59:48 +00:00
Michael Brown 6816006808 [linux] Use generic sysfs mechanism to read ACPI tables
Signed-off-by: Michael Brown <mcb30@ipxe.org>
2021-03-02 23:59:46 +00:00
Michael Brown 5c8a9905ce [linux] Add a generic function for reading files from sysfs
Signed-off-by: Michael Brown <mcb30@ipxe.org>
2021-03-02 23:59:30 +00:00
Michael Brown 976839ae4c [linux] Free cached ACPI tables on shutdown
Free any cached ACPI tables for the sake of neatness (and a clean
report from Valgrind).

Signed-off-by: Michael Brown <mcb30@ipxe.org>
2021-03-02 23:59:27 +00:00
Michael Brown 3b8aff94bf [build] Fix building on older versions of gcc
Versions of gcc prior to 9.1 do not support the single-argument form
of static_assert().  Fix by unconditionally defining a compatibility
macro for the single file that uses this.

Signed-off-by: Michael Brown <mcb30@ipxe.org>
2021-03-02 16:47:22 +00:00
Michael Brown 2b5d3f582f [slirp] Add libslirp driver for Linux
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>
2021-03-02 11:09:57 +00:00
Michael Brown c09b627973 [linux] Provide ACPI settings via /sys/firmware/acpi/tables
Signed-off-by: Michael Brown <mcb30@ipxe.org>
2021-03-01 01:38:54 +00:00
Michael Brown 9776f6ece1 [acpi] Allow for platforms that provide ACPI tables individually
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>
2021-03-01 00:08:23 +00:00
Michael Brown f309d7a7b7 [linux] Use host glibc system call wrappers
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>
2021-02-28 23:28:23 +00:00
Michael Brown cd3de55ea5 [efi] Record cached DHCPACK from loaded image's device handle, if present
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>
2021-02-17 18:11:43 +00:00
Michael Brown d562339fca [efi] Defer autoboot link-layer address and autoexec script probing
The code to detect the autoboot link-layer address and to load the
autoexec script currently runs before the call to initialise() and so
has to function without a working heap.

This requirement can be relaxed by deferring this code to run via an
initialisation function.  This gives the code a normal runtime
environment, but still invokes it early enough to guarantee that the
original loaded image device handle has not yet been invalidated.

Signed-off-by: Michael Brown <mcb30@ipxe.org>
2021-02-17 17:14:19 +00:00
Michael Brown e39cd79a00 [efi] Split out autoexec script portions of efi_autoboot.c
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>
2021-02-17 17:14:19 +00:00
Michael Brown 885c6d6e98 [efi] Fix erroneous comparison of a pointer against userptr_t
Signed-off-by: Michael Brown <mcb30@ipxe.org>
2021-02-03 16:00:06 +00:00
Michael Brown a08244ecc4 [efi] Use EFI_SIMPLE_TEXT_INPUT_EX_PROTOCOL if available
The original EFI_SIMPLE_TEXT_INPUT_PROTOCOL is not technically
required to handle the use of the Ctrl key, and the long-obsolete EFI
1.10 specification lists only backspace, tab, linefeed, and carriage
return as required.  Some particularly brain-dead vendor UEFI firmware
implementations dutifully put in the extra effort of ensuring that all
other control characters (such as Ctrl-C) are impossible to type via
EFI_SIMPLE_TEXT_INPUT_PROTOCOL.

Current versions of the UEFI specification mandate that the console
input handle must support both EFI_SIMPLE_TEXT_INPUT_PROTOCOL and
EFI_SIMPLE_TEXT_INPUT_EX_PROTOCOL, the latter of which at least
provides access to modifier key state.

Unlike EFI_SIMPLE_TEXT_INPUT_PROTOCOL, the pointer to the
EFI_SIMPLE_TEXT_INPUT_EX_PROTOCOL instance does not appear within the
EFI system table and must therefore be opened explicitly.  The UEFI
specification provides no safe way to do so, since we cannot open the
handle BY_DRIVER or BY_CHILD_CONTROLLER and so nothing guarantees that
this pointer will remain valid for the lifetime of iPXE.  We must
simply hope that no UEFI firmware implementation ever discovers a
motivation for reinstalling the EFI_SIMPLE_TEXT_INPUT_EX_PROTOCOL
instance.

Use EFI_SIMPLE_TEXT_INPUT_EX_PROTOCOL if available, falling back to
the existing EFI_SIMPLE_TEXT_PROTOCOL otherwise.

Signed-off-by: Michael Brown <mcb30@ipxe.org>
2021-01-27 12:45:53 +00:00
Michael Brown 4f9fbe6c16 [efi] Fix misleading debug message
Signed-off-by: Michael Brown <mcb30@ipxe.org>
2021-01-26 22:25:18 +00:00
Michael Brown ade4d2b4fe [efi] Fix use of uninitialised variable
Signed-off-by: Michael Brown <mcb30@ipxe.org>
2021-01-26 11:30:50 +00:00
Michael Brown a3f1e8fb67 [efi] Automatically load "/autoexec.ipxe" when booted from a filesystem
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>
2021-01-25 17:04:44 +00:00
Michael Brown 5aa389593d [efi] Leave asynchronous USB endpoints open until device is removed
Some UEFI device drivers will react to an asynchronous USB transfer
failure by dubiously terminating the scheduled transfer from within
the completion handler.

We already have code from commit fbb776f ("[efi] Leave USB endpoint
descriptors in existence until device is removed") that avoids freeing
memory in this situation, in order to avoid use-after-free bugs.  This
is not sufficient to avoid potential problems, since with an xHCI
controller the act of closing the endpoint requires issuing a command
and awaiting completion via the event ring, which may in turn dispatch
further USB transfer completion events.

Avoid these problems by leaving the USB endpoint open (but with the
refill timer stopped) until the device is finally removed, as is
already done for control and bulk transfers.

Signed-off-by: Michael Brown <mcb30@ipxe.org>
2021-01-03 20:23:51 +00:00
Michael Brown 988d2c13cd [efi] Use segment and bus number to identify PCI root bridge I/O protocol
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>
2020-12-31 21:03:10 +00:00
Michael Brown dced22d6de [smbios] Add support for the 64-bit SMBIOS3 entry point
Support UEFI systems that provide only 64-bit versions of the SMBIOS
entry point.

Signed-off-by: Michael Brown <mcb30@ipxe.org>
2020-12-29 14:41:50 +00:00
b1f6c1c4 485f8ce554 [efi] Allow for longer device paths in debug messages
Modified-by: Michael Brown <mcb30@ipxe.org>
Signed-off-by: Michael Brown <mcb30@ipxe.org>
2020-12-29 13:16:22 +00:00
Michael Brown 47098d7cb1 [efi] Allow EFI_USB_IO_PROTOCOL interfaces to be nullified and leaked
Signed-off-by: Michael Brown <mcb30@ipxe.org>
2020-12-17 21:46:52 +00:00
Michael Brown 6769a7c3c6 [efi] Skip interface uninstallation during shutdown
iPXE seems to be almost alone in the UEFI world in attempting to shut
down cleanly, free resources, and leave hardware in a well-defined
reset state before handing over to the booted operating system.

The UEFI driver model does allow for graceful shutdown via
uninstallation of protocol interfaces.  However, virtually no other
UEFI drivers do this, and the external code paths that react to
uninstallation are consequently poorly tested.  This leads to a
proliferation of bugs found in UEFI implementations in the wild, as
described in commits such as 1295b4a ("[efi] Allow initialisation via
SNP interface even while claimed") or b6e2ea0 ("[efi] Veto the HP
XhciDxe Driver").

Try to avoid triggering such bugs by unconditionally skipping the
protocol interface uninstallation during UEFI boot services shutdown,
leaving the interfaces present but nullified and deliberately leaking
the containing memory.

Signed-off-by: Michael Brown <mcb30@ipxe.org>
2020-12-17 21:32:49 +00:00